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DWR的学习文档（Hello World,类型转换,Spring,Annotation)
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DWR的学习文档（Hello World,类型转换,Spring,Annotation)
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來源：http://www.iteye.com/topic/40313
DWR是作為遠程調用的ajax框架，將服務端的java類，方法和瀏覽器的javascript的類，方法對應起來。現在官方最新的版本是DWR2.0，可以在http://getahead.ltd.uk/dwr/download下載到。
我們真對DWR2.0做一些例子講解一下它的特性：
Hello World：
新建一個web項目DWRStudy，在項目中構建路徑中加入dwr.jar，
新建類Hello如下：
Java代碼
package org.li.dwr;
package org.li.dwr;
import java.util.Date;
public class Hello
{
public String getHelloWorld()
{
return "現在的時間為："+new Date();
}
}
package org.li.dwr;
package org.li.dwr;
import java.util.Date;
public class Hello
{
public String getHelloWorld()
{
return "現在的時間為："+new Date();
}
}
在WEB-INF目錄下新建dwr.xml文件：
Java代碼
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd">
<dwr>
<allow>
<!-- javascript的對象是jshello,create="new"是DWR自己創建類 -->
<create javascript="jshello" creator="new" scope="application">
<param name="class" value="org.li.dwr.Hello"></param>
</create>
</allow>
</dwr>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd">
<dwr>
<allow>
<!-- javascript的對象是jshello,create="new"是DWR自己創建類 -->
<create javascript="jshello" creator="new" scope="application">
<param name="class" value="org.li.dwr.Hello"></param>
</create>
</allow>
</dwr>
在WebRoot目錄里新建hello.js
Java代碼
function load()//載入的時候調用
{
var jbutton = document.getElementById("jbutton");
jbutton.onclick=function(event)//注冊按鈕點擊事件
{
jbClick();
};
}
function jbClick()//按鈕點擊事件
{
jshello.getHelloWorld(callback);//沒有參數傳遞，只傳遞回調函數就行
}
function callback(msg)//回調函數
{
DWRUtil.setValue('jdiv',msg);
}
function load()//載入的時候調用
{
var jbutton = document.getElementById("jbutton");
jbutton.onclick=function(event)//注冊按鈕點擊事件
{
jbClick();
};
}
function jbClick()//按鈕點擊事件
{
jshello.getHelloWorld(callback);//沒有參數傳遞，只傳遞回調函數就行
}
function callback(msg)//回調函數
{
DWRUtil.setValue('jdiv',msg);
}
在WebRoot目錄里新建HelloWorld.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>HelloWorld.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jshello.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="hello.js"></script>
</head>
<body>
<input id="jbutton" type="button" value="得到Hello World"/>
<div id="jdiv"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>HelloWorld.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jshello.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="hello.js"></script>
</head>
<body>
<input id="jbutton" type="button" value="得到Hello World"/>
<div id="jdiv"></div>
<script>load()</script>
</body>
</html>
在web.xml中加入一個dwr的servlet：
Java代碼
<servlet>
<servlet-name>dwr-invoker</servlet-name>
<servlet-class>
org.directwebremoting.servlet.DwrServlet
</servlet-class>
<init-param>
<param-name>debug</param-name>
<param-value>true</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>dwr-invoker</servlet-name>
<servlet-class>
org.directwebremoting.servlet.DwrServlet
</servlet-class>
<init-param>
<param-name>debug</param-name>
<param-value>true</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
在運行一下服務器在瀏覽器里輸入http://localhost:8080/DWRStudy/HelloWorld.html，然后點一下按鈕下面就會顯示服務端的系統時間了，而瀏覽器頁面并沒有被刷新。
下面解釋一下：
1. 新建的Hello類中有一個getHelloWorld方法這個方法就是作為遠程調用的服務端方法，這個Hello類也就是遠程調用的類。方法的返回值為服務端當前的時間
2. dwr.xml是DWR用來配置服務端類和瀏覽器端javascript類之間的映射。可以下載dtd看一下，在<allow></allow>里類配置映射類如：<create javascript="jshello" creator="new" scope="application">
<param name="class" value="org.li.dwr.Hello"></param>
</create>
javascript="jshello"是在瀏覽器端的javascript的映射的類名，（不要用javascript里的關鍵字）creator="new"是表示這個類是dwr自己創建的，如果creator="new"那么就必須有下面的<param name=”class” value=”類的全路徑”></param>，creator還可為spring(與spring集成的時候),script(與apache的一個框架BSF集成的時候用),后來又加入了struts,jsf,ejb3.現在是個HelloWorld讓大家體驗一下，具體后面會細講。最后的scope=”application”是說這個pojo類的范圍，和jsp是一樣的。
3. 創建hello.js和HelloWorld.html都是看自己是怎么發揮了，注意的是在HelloWorld.html中導入js文件的時候注意順序和路徑命名規律，自己發揮的這個hello.js一定放在后面，因為要調用其它js文件中的函數。由于在HelloWorld.html里寫入了<script>load()</script>所以在html加載的時候會調用hello.js里的load方法(注意這幾個js文件里的函數最好不要重名)在load里面做的事情就是注冊一下id為jbutton的按鈕的點擊事件。當我們點擊id為jbutton的按鈕的時候就開始用與服務器端的類相對應的javascript類了（jshello），直接調用jshello類的getHelloWorld方法，可以向函數傳遞參數，不過要在最后加一個回調函數。而我們的服務端的類沒有參數就直接傳回調函數了。在回調函數的形參msg是服務端Hello類中getHelloWorld方法返回值。在回調函數里面調用了DWR的工具類DWRUtil類的setValue方法設置id為jdiv的值。另外我們把doucment.getElementById(“jbutton”);換與$(“jbutton”)也可以得到同樣的效果，這就有點像prototype了。
4. 在web.xml里加入DWRServlet的配置一是為了遠程調用，二是自動生成了<script type='text/javascript' src='dwr/interface/jshello.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>文件。
上個HelloWorld例子只是返回了一個字符串，當然我們顯示字符串很容易，可是如果返回一個對象怎么辦呢？，DWR為我們將java類和javascript的DOM對象，不過這得需要我們在dwr.xml里配置。
再看一個綜合的例子：
新建類User
Java代碼
package org.li.dwr;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public List<Book> getBook()
{
this.books = new ArrayList<Book>();
Book javaBook = new Book();
Book vcBook = new Book();
javaBook.setAuthor("孫鑫");
vcBook.setAuthor("孫鑫");
javaBook.setName("java Web開發詳解");
vcBook.setName("vc++深入詳解");
this.books.add(javaBook);
this.books.add(vcBook);
return this.books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
try
{
FileInputStream fis = new FileInputStream("D:\\workspace\\DWRStudy\\src\\user.properties");
Properties pp = new Properties();
pp.load(fis);
this.username=pp.getProperty("username");
this.age=Integer.valueOf(pp.getProperty("age"));
this.address=pp.getProperty("address");
fis.close();
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return this;
}
}
package org.li.dwr;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public List<Book> getBook()
{
this.books = new ArrayList<Book>();
Book javaBook = new Book();
Book vcBook = new Book();
javaBook.setAuthor("孫鑫");
vcBook.setAuthor("孫鑫");
javaBook.setName("java Web開發詳解");
vcBook.setName("vc++深入詳解");
this.books.add(javaBook);
this.books.add(vcBook);
return this.books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
try
{
FileInputStream fis = new FileInputStream("D:\\workspace\\DWRStudy\\src\\user.properties");
Properties pp = new Properties();
pp.load(fis);
this.username=pp.getProperty("username");
this.age=Integer.valueOf(pp.getProperty("age"));
this.address=pp.getProperty("address");
fis.close();
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return this;
}
}
新建Book類：
Java代碼
package org.li.dwr;
public class Book
{
private String name;
private String author;
public String getAuthor()
{
return author;
}
public void setAuthor(String author)
{
this.author = author;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}
package org.li.dwr;
public class Book
{
private String name;
private String author;
public String getAuthor()
{
return author;
}
public void setAuthor(String author)
{
this.author = author;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}
新建DWRLog類
Java代碼
package org.li.dwr.log;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilterChain;
public class DWRLog implements org.directwebremoting.AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method,params);
}
}
package org.li.dwr.log;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilterChain;
public class DWRLog implements org.directwebremoting.AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method,params);
}
}
新建D:\\workspace\\DWRStudy\\src\\user.properties
username=javafish
age=21
address=北京市海淀區
然后在dwr.xml里加入
Java代碼
<create javascript="jsuser" creator="new">
<param name="class" value="org.li.dwr.User"></param>
<!-- 過濾允許調用的方法 -->
<include method="getUser"/>
<include method="getBook"/>
<!-- 配置自己的過濾器 -->
<filter class="org.li.dwr.log.DWRLog"></filter>
</create>
<!-- 需要轉換的類 -->
<convert match="org.li.dwr.User" converter="bean"></convert>
<convert match="org.li.dwr.Book" converter="bean"></convert>
<create javascript="jsuser" creator="new">
<param name="class" value="org.li.dwr.User"></param>
<!-- 過濾允許調用的方法 -->
<include method="getUser"/>
<include method="getBook"/>
<!-- 配置自己的過濾器 -->
<filter class="org.li.dwr.log.DWRLog"></filter>
</create>
<!-- 需要轉換的類 -->
<convert match="org.li.dwr.User" converter="bean"></convert>
<convert match="org.li.dwr.Book" converter="bean"></convert>
新建UserInfo.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jsuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="userInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish的信息"/>
<input id="sbutton" type="button" value="得到javafish的書"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jsuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="userInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish的信息"/>
<input id="sbutton" type="button" value="得到javafish的書"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
新建userInfo.js
Java代碼
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
jsuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address+user.books[0].author);
}
function sOnClick()
{
jsuser.getBook(callbackBooks);
}
function callbackBooks(msg)
{
alert(msg);
DWRUtil.setValue('result',msg);
}
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
jsuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address+user.books[0].author);
}
function sOnClick()
{
jsuser.getBook(callbackBooks);
}
function callbackBooks(msg)
{
alert(msg);
DWRUtil.setValue('result',msg);
}
運行服務器輸入http://localhost:8080/DWRStudy/UserInfo.html，可看到運行結果
這個例子需要解釋的就是dwr.xml了
在這里用到了兩個java類，User、Book，方法呢就是User.getUser和User.getBook，而Book類呢由于我們沒有在javascript中調用，所以就不用配置Book的create了。
大家可能會奇怪為什么會多出來兩個<convert match="org.li.dwr.User" converter="bean"></convert>
<convert match="org.li.dwr.Book" converter="bean"></convert>
呢，是因為在調用getBook和getUser的時候會返回給javascript有關User和Book的對象或數據，這里的用<convert match=”類” converter=”bean”/>做一下轉換，否則javascript將不會得到有效的數據。
下面討論一下DWR的安全性，由于我們將javaBean整體都對外暴露了，所以說會有非常多的安全問題，真對這些DWR也作了一些的措施就是上面例子中dwr.xml的配置：
<include method="getUser"/>
<include method="getBook"/>
<filter class="org.li.dwr.log.DWRLog"></filter>
這樣配置的話就只暴露了User類的兩個方法getUser,getBook。就相對安全多了，相反還有<exclude>的配置它們是類似的。對于安全我們也可以用DWR的過濾器來實現，這里我用過濾器實現的是一個日志記錄。過濾器類只需要實現AjaxFilter接口就可以了，不過注意的是這個過濾器不是HttpServelt的過濾器而是DWR自己內部實現的（有興趣可以查看一下源代碼）。
真對DWR的安全性上來說，官方也不敢保證，官方只是說自己可以看一下源代碼因地施宜。
不過DWR可以和acegi集成，讓acegi來管理安全問題。由于acegi我還沒有完全搞定關于DWR和acegi的集成，先放一放日后補充。
下面對DWR.xml的配置具體補充一下：
首先是<init></init>里面有<converter>和<create>是配置在初始化的時候需要創建和轉化的類。
然后是<allow></allow>里面有<converter>和<create>這個地方就是正式的配置了，creator里有param,filter,include,exclude,auth，除了auth我們都接觸過了，而auth是集成J2EE的安全認證用的，這個可能和acegi的集成有關吧（？）。<converter>呢，它的converter有很多
? Array Converter
? Bean and Object Converters
? Collection Converter
? Enum Converter
? DOM Objects
這些都是轉換的時候配置的
還有就是<signatures></signatures>的配置了，申明一些不java用反射不可得到的參數類型。
我在上面例子上用的getBook來本來想用signatures實現List<Book>的轉換可是沒有成功（不用配置就可以）
主要是真對jdk1.4以下的，我本機用的是jdk6,所以屢試不爽最后在官方DWR2的特性中看到如果你用的是DWR2和JDK5以上的話就不用配置了DWR會自動轉換。
下面講一下DWR與Spring的集成：
還是上面那個例子用Spring搞定大部分和上面一樣
新建類User（包換了）
Java代碼
package org.li.dwr.spring;
import java.util.List;
import org.li.dwr.Book;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
package org.li.dwr.spring;
import java.util.List;
import org.li.dwr.Book;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
Book還是以前那個
在src下新建application.xml文件（spring的配置文件）
Java代碼
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="user" class="org.li.dwr.spring.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
</beans>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="user" class="org.li.dwr.spring.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
</beans>
在dwr.xml加入：
Java代碼
<create javascript="springUser" creator="spring">
<param name="beanName" value="user"></param>
<!-- 指定Spring配置文件的位置，如果沒設置DWR會根據web.xml找到主配置文件，不過速度上就慢了 -->
<param name="location" value="applicationContext.xml"></param>
</create><convert match="org.li.dwr.spring.User" converter="bean"></convert>
<create javascript="springUser" creator="spring">
<param name="beanName" value="user"></param>
<!-- 指定Spring配置文件的位置，如果沒設置DWR會根據web.xml找到主配置文件，不過速度上就慢了 -->
<param name="location" value="applicationContext.xml"></param>
</create><convert match="org.li.dwr.spring.User" converter="bean"></convert>
新建springUserInfo.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/springUser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="springuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/springUser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="springuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
新建springUserInfo.js
Java代碼
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
springUser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
springUser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
在web.xml中加入
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/classes/applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
運行服務器輸入http://localhost:8080/DWRStudy/springUserInfo.html，可以看到運行結果
主要的區別是dwr.xml的配置，需要在creator=spring,然后里面的<param>的name用beanName,值是spring的配置文件里的bean的id。Name=location是指定spring的配置文件的路徑（如果不指定DWR可以根據web.xml自動找到spring的主配置文件）。
DWR的Annotation配置
還是上面spring那個例子的功能再來一遍(new 的配置太簡單)，這樣的話項目中的dwr.xml對于這個例子就沒有作用了
新建User類（包名換了）
Java代碼
package org.li.dwr.spring.annotation;
import java.util.List;
import org.directwebremoting.annotations.Convert;
import org.directwebremoting.annotations.Create;
import org.directwebremoting.annotations.Param;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProperty;
import org.directwebremoting.convert.BeanConverter;
import org.directwebremoting.spring.SpringCreator;
import org.li.dwr.Book;
@Create(creator=SpringCreator.class,name="anspringuser",creatorParams={@Param(name="beanName",value="anuser"),@Param(name="location",value="applicationContext.xml")})
@Convert(converter=BeanConverter.class)
public class User
{
private String welcome;
private String username;
@RemoteProperty
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
@RemoteMethod
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
package org.li.dwr.spring.annotation;
import java.util.List;
import org.directwebremoting.annotations.Convert;
import org.directwebremoting.annotations.Create;
import org.directwebremoting.annotations.Param;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProperty;
import org.directwebremoting.convert.BeanConverter;
import org.directwebremoting.spring.SpringCreator;
import org.li.dwr.Book;
@Create(creator=SpringCreator.class,name="anspringuser",creatorParams={@Param(name="beanName",value="anuser"),@Param(name="location",value="applicationContext.xml")})
@Convert(converter=BeanConverter.class)
public class User
{
private String welcome;
private String username;
@RemoteProperty
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
@RemoteMethod
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
新建過濾器類DWRAnLog
Java代碼
package org.li.dwr.log.annotation;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilter;
import org.directwebremoting.AjaxFilterChain;
import org.directwebremoting.annotations.Filter;
import org.directwebremoting.filter.SpringTransactionAjaxFilter;
@Filter(type=SpringTransactionAjaxFilter.class)
public class DWRAnLog implements AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("annotation過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method, params);
}
}
package org.li.dwr.log.annotation;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilter;
import org.directwebremoting.AjaxFilterChain;
import org.directwebremoting.annotations.Filter;
import org.directwebremoting.filter.SpringTransactionAjaxFilter;
@Filter(type=SpringTransactionAjaxFilter.class)
public class DWRAnLog implements AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("annotation過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method, params);
}
}
在spring的applicationContext.xml里加入
Java代碼
<bean id="anuser" class="org.li.dwr.spring.annotation.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
<bean id="anuser" class="org.li.dwr.spring.annotation.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
新建AnSpringUserInfoHtml.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/anspringuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="anspringuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/anspringuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="anspringuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
新建anspringuserInfo.js
Java代碼
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
}
function bOnClick()
{
alert("haha");
anspringuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
}
function bOnClick()
{
alert("haha");
anspringuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
在web.xml中
的DWR的servlet的初始化參數里加入
Java代碼
<init-param>
<param-name>classes</param-name>
<param-value>
org.li.dwr.log.annotation.DWRAnLog,org.li.dwr.spring.annotation.User
</param-value>
</init-param>
<init-param>
<param-name>classes</param-name>
<param-value>
org.li.dwr.log.annotation.DWRAnLog,org.li.dwr.spring.annotation.User
</param-value>
</init-param>
運行服務器輸入http://localhost:8080/DWRStudy/AnSpringUserInfo.html，成功了
用Annotation的配置和dwr.xml的意思基本一樣，這里就不多做介紹了。
Util.js的函數庫
$()和prototype.js一樣相當于document.getElementById
(Set)getValue（）(設置)得到元素的值一般是（設置）得到元素的innerHTML。
getText()得到元素的文本值
(set)getValues()（設置）得到元素下的元素，以array為對象載體。
這里都是一些最常用的函數，具體可以看一下util.js文件。
DWR是作為遠程調用的ajax框架，將服務端的java類，方法和瀏覽器的javascript的類，方法對應起來。現在官方最新的版本是DWR2.0，可以在http://getahead.ltd.uk/dwr/download下載到。
我們真對DWR2.0做一些例子講解一下它的特性：
Hello World：
新建一個web項目DWRStudy，在項目中構建路徑中加入dwr.jar，
新建類Hello如下：
Java代碼
package org.li.dwr;
package org.li.dwr;
import java.util.Date;
public class Hello
{
public String getHelloWorld()
{
return "現在的時間為："+new Date();
}
}
package org.li.dwr;
package org.li.dwr;
import java.util.Date;
public class Hello
{
public String getHelloWorld()
{
return "現在的時間為："+new Date();
}
}
在WEB-INF目錄下新建dwr.xml文件：
Java代碼
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd">
<dwr>
<allow>
<!-- javascript的對象是jshello,create="new"是DWR自己創建類 -->
<create javascript="jshello" creator="new" scope="application">
<param name="class" value="org.li.dwr.Hello"></param>
</create>
</allow>
</dwr>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr/dwr20.dtd">
<dwr>
<allow>
<!-- javascript的對象是jshello,create="new"是DWR自己創建類 -->
<create javascript="jshello" creator="new" scope="application">
<param name="class" value="org.li.dwr.Hello"></param>
</create>
</allow>
</dwr>
在WebRoot目錄里新建hello.js
Java代碼
function load()//載入的時候調用
{
var jbutton = document.getElementById("jbutton");
jbutton.onclick=function(event)//注冊按鈕點擊事件
{
jbClick();
};
}
function jbClick()//按鈕點擊事件
{
jshello.getHelloWorld(callback);//沒有參數傳遞，只傳遞回調函數就行
}
function callback(msg)//回調函數
{
DWRUtil.setValue('jdiv',msg);
}
function load()//載入的時候調用
{
var jbutton = document.getElementById("jbutton");
jbutton.onclick=function(event)//注冊按鈕點擊事件
{
jbClick();
};
}
function jbClick()//按鈕點擊事件
{
jshello.getHelloWorld(callback);//沒有參數傳遞，只傳遞回調函數就行
}
function callback(msg)//回調函數
{
DWRUtil.setValue('jdiv',msg);
}
在WebRoot目錄里新建HelloWorld.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>HelloWorld.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jshello.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="hello.js"></script>
</head>
<body>
<input id="jbutton" type="button" value="得到Hello World"/>
<div id="jdiv"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>HelloWorld.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jshello.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="hello.js"></script>
</head>
<body>
<input id="jbutton" type="button" value="得到Hello World"/>
<div id="jdiv"></div>
<script>load()</script>
</body>
</html>
在web.xml中加入一個dwr的servlet：
Java代碼
<servlet>
<servlet-name>dwr-invoker</servlet-name>
<servlet-class>
org.directwebremoting.servlet.DwrServlet
</servlet-class>
<init-param>
<param-name>debug</param-name>
<param-value>true</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>dwr-invoker</servlet-name>
<servlet-class>
org.directwebremoting.servlet.DwrServlet
</servlet-class>
<init-param>
<param-name>debug</param-name>
<param-value>true</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dwr-invoker</servlet-name>
<url-pattern>/dwr/*</url-pattern>
</servlet-mapping>
在運行一下服務器在瀏覽器里輸入http://localhost:8080/DWRStudy/HelloWorld.html，然后點一下按鈕下面就會顯示服務端的系統時間了，而瀏覽器頁面并沒有被刷新。
下面解釋一下：
1. 新建的Hello類中有一個getHelloWorld方法這個方法就是作為遠程調用的服務端方法，這個Hello類也就是遠程調用的類。方法的返回值為服務端當前的時間
2. dwr.xml是DWR用來配置服務端類和瀏覽器端javascript類之間的映射。可以下載dtd看一下，在<allow></allow>里類配置映射類如：<create javascript="jshello" creator="new" scope="application">
<param name="class" value="org.li.dwr.Hello"></param>
</create>
javascript="jshello"是在瀏覽器端的javascript的映射的類名，（不要用javascript里的關鍵字）creator="new"是表示這個類是dwr自己創建的，如果creator="new"那么就必須有下面的<param name=”class” value=”類的全路徑”></param>，creator還可為spring(與spring集成的時候),script(與apache的一個框架BSF集成的時候用),后來又加入了struts,jsf,ejb3.現在是個HelloWorld讓大家體驗一下，具體后面會細講。最后的scope=”application”是說這個pojo類的范圍，和jsp是一樣的。
3. 創建hello.js和HelloWorld.html都是看自己是怎么發揮了，注意的是在HelloWorld.html中導入js文件的時候注意順序和路徑命名規律，自己發揮的這個hello.js一定放在后面，因為要調用其它js文件中的函數。由于在HelloWorld.html里寫入了<script>load()</script>所以在html加載的時候會調用hello.js里的load方法(注意這幾個js文件里的函數最好不要重名)在load里面做的事情就是注冊一下id為jbutton的按鈕的點擊事件。當我們點擊id為jbutton的按鈕的時候就開始用與服務器端的類相對應的javascript類了（jshello），直接調用jshello類的getHelloWorld方法，可以向函數傳遞參數，不過要在最后加一個回調函數。而我們的服務端的類沒有參數就直接傳回調函數了。在回調函數的形參msg是服務端Hello類中getHelloWorld方法返回值。在回調函數里面調用了DWR的工具類DWRUtil類的setValue方法設置id為jdiv的值。另外我們把doucment.getElementById(“jbutton”);換與$(“jbutton”)也可以得到同樣的效果，這就有點像prototype了。
4. 在web.xml里加入DWRServlet的配置一是為了遠程調用，二是自動生成了<script type='text/javascript' src='dwr/interface/jshello.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>文件。
上個HelloWorld例子只是返回了一個字符串，當然我們顯示字符串很容易，可是如果返回一個對象怎么辦呢？，DWR為我們將java類和javascript的DOM對象，不過這得需要我們在dwr.xml里配置。
再看一個綜合的例子：
新建類User
Java代碼
package org.li.dwr;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public List<Book> getBook()
{
this.books = new ArrayList<Book>();
Book javaBook = new Book();
Book vcBook = new Book();
javaBook.setAuthor("孫鑫");
vcBook.setAuthor("孫鑫");
javaBook.setName("java Web開發詳解");
vcBook.setName("vc++深入詳解");
this.books.add(javaBook);
this.books.add(vcBook);
return this.books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
try
{
FileInputStream fis = new FileInputStream("D:\\workspace\\DWRStudy\\src\\user.properties");
Properties pp = new Properties();
pp.load(fis);
this.username=pp.getProperty("username");
this.age=Integer.valueOf(pp.getProperty("age"));
this.address=pp.getProperty("address");
fis.close();
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return this;
}
}
package org.li.dwr;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public List<Book> getBook()
{
this.books = new ArrayList<Book>();
Book javaBook = new Book();
Book vcBook = new Book();
javaBook.setAuthor("孫鑫");
vcBook.setAuthor("孫鑫");
javaBook.setName("java Web開發詳解");
vcBook.setName("vc++深入詳解");
this.books.add(javaBook);
this.books.add(vcBook);
return this.books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
try
{
FileInputStream fis = new FileInputStream("D:\\workspace\\DWRStudy\\src\\user.properties");
Properties pp = new Properties();
pp.load(fis);
this.username=pp.getProperty("username");
this.age=Integer.valueOf(pp.getProperty("age"));
this.address=pp.getProperty("address");
fis.close();
}
catch (FileNotFoundException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
return this;
}
}
新建Book類：
Java代碼
package org.li.dwr;
public class Book
{
private String name;
private String author;
public String getAuthor()
{
return author;
}
public void setAuthor(String author)
{
this.author = author;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}
package org.li.dwr;
public class Book
{
private String name;
private String author;
public String getAuthor()
{
return author;
}
public void setAuthor(String author)
{
this.author = author;
}
public String getName()
{
return name;
}
public void setName(String name)
{
this.name = name;
}
}
新建DWRLog類
Java代碼
package org.li.dwr.log;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilterChain;
public class DWRLog implements org.directwebremoting.AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method,params);
}
}
package org.li.dwr.log;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilterChain;
public class DWRLog implements org.directwebremoting.AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method,params);
}
}
新建D:\\workspace\\DWRStudy\\src\\user.properties
username=javafish
age=21
address=北京市海淀區
然后在dwr.xml里加入
Java代碼
<create javascript="jsuser" creator="new">
<param name="class" value="org.li.dwr.User"></param>
<!-- 過濾允許調用的方法 -->
<include method="getUser"/>
<include method="getBook"/>
<!-- 配置自己的過濾器 -->
<filter class="org.li.dwr.log.DWRLog"></filter>
</create>
<!-- 需要轉換的類 -->
<convert match="org.li.dwr.User" converter="bean"></convert>
<convert match="org.li.dwr.Book" converter="bean"></convert>
<create javascript="jsuser" creator="new">
<param name="class" value="org.li.dwr.User"></param>
<!-- 過濾允許調用的方法 -->
<include method="getUser"/>
<include method="getBook"/>
<!-- 配置自己的過濾器 -->
<filter class="org.li.dwr.log.DWRLog"></filter>
</create>
<!-- 需要轉換的類 -->
<convert match="org.li.dwr.User" converter="bean"></convert>
<convert match="org.li.dwr.Book" converter="bean"></convert>
新建UserInfo.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jsuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="userInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish的信息"/>
<input id="sbutton" type="button" value="得到javafish的書"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/jsuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="userInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish的信息"/>
<input id="sbutton" type="button" value="得到javafish的書"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
新建userInfo.js
Java代碼
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
jsuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address+user.books[0].author);
}
function sOnClick()
{
jsuser.getBook(callbackBooks);
}
function callbackBooks(msg)
{
alert(msg);
DWRUtil.setValue('result',msg);
}
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
jsuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address+user.books[0].author);
}
function sOnClick()
{
jsuser.getBook(callbackBooks);
}
function callbackBooks(msg)
{
alert(msg);
DWRUtil.setValue('result',msg);
}
運行服務器輸入http://localhost:8080/DWRStudy/UserInfo.html，可看到運行結果
這個例子需要解釋的就是dwr.xml了
在這里用到了兩個java類，User、Book，方法呢就是User.getUser和User.getBook，而Book類呢由于我們沒有在javascript中調用，所以就不用配置Book的create了。
大家可能會奇怪為什么會多出來兩個<convert match="org.li.dwr.User" converter="bean"></convert>
<convert match="org.li.dwr.Book" converter="bean"></convert>
呢，是因為在調用getBook和getUser的時候會返回給javascript有關User和Book的對象或數據，這里的用<convert match=”類” converter=”bean”/>做一下轉換，否則javascript將不會得到有效的數據。
下面討論一下DWR的安全性，由于我們將javaBean整體都對外暴露了，所以說會有非常多的安全問題，真對這些DWR也作了一些的措施就是上面例子中dwr.xml的配置：
<include method="getUser"/>
<include method="getBook"/>
<filter class="org.li.dwr.log.DWRLog"></filter>
這樣配置的話就只暴露了User類的兩個方法getUser,getBook。就相對安全多了，相反還有<exclude>的配置它們是類似的。對于安全我們也可以用DWR的過濾器來實現，這里我用過濾器實現的是一個日志記錄。過濾器類只需要實現AjaxFilter接口就可以了，不過注意的是這個過濾器不是HttpServelt的過濾器而是DWR自己內部實現的（有興趣可以查看一下源代碼）。
真對DWR的安全性上來說，官方也不敢保證，官方只是說自己可以看一下源代碼因地施宜。
不過DWR可以和acegi集成，讓acegi來管理安全問題。由于acegi我還沒有完全搞定關于DWR和acegi的集成，先放一放日后補充。
下面對DWR.xml的配置具體補充一下：
首先是<init></init>里面有<converter>和<create>是配置在初始化的時候需要創建和轉化的類。
然后是<allow></allow>里面有<converter>和<create>這個地方就是正式的配置了，creator里有param,filter,include,exclude,auth，除了auth我們都接觸過了，而auth是集成J2EE的安全認證用的，這個可能和acegi的集成有關吧（？）。<converter>呢，它的converter有很多
? Array Converter
? Bean and Object Converters
? Collection Converter
? Enum Converter
? DOM Objects
這些都是轉換的時候配置的
還有就是<signatures></signatures>的配置了，申明一些不java用反射不可得到的參數類型。
我在上面例子上用的getBook來本來想用signatures實現List<Book>的轉換可是沒有成功（不用配置就可以）
主要是真對jdk1.4以下的，我本機用的是jdk6,所以屢試不爽最后在官方DWR2的特性中看到如果你用的是DWR2和JDK5以上的話就不用配置了DWR會自動轉換。
下面講一下DWR與Spring的集成：
還是上面那個例子用Spring搞定大部分和上面一樣
新建類User（包換了）
Java代碼
package org.li.dwr.spring;
import java.util.List;
import org.li.dwr.Book;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
package org.li.dwr.spring;
import java.util.List;
import org.li.dwr.Book;
public class User
{
private String welcome;
private String username;
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
Book還是以前那個
在src下新建application.xml文件（spring的配置文件）
Java代碼
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="user" class="org.li.dwr.spring.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
</beans>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
<beans>
<bean id="user" class="org.li.dwr.spring.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
</beans>
在dwr.xml加入：
Java代碼
<create javascript="springUser" creator="spring">
<param name="beanName" value="user"></param>
<!-- 指定Spring配置文件的位置，如果沒設置DWR會根據web.xml找到主配置文件，不過速度上就慢了 -->
<param name="location" value="applicationContext.xml"></param>
</create><convert match="org.li.dwr.spring.User" converter="bean"></convert>
<create javascript="springUser" creator="spring">
<param name="beanName" value="user"></param>
<!-- 指定Spring配置文件的位置，如果沒設置DWR會根據web.xml找到主配置文件，不過速度上就慢了 -->
<param name="location" value="applicationContext.xml"></param>
</create><convert match="org.li.dwr.spring.User" converter="bean"></convert>
新建springUserInfo.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/springUser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="springuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/springUser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="springuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
新建springUserInfo.js
Java代碼
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
springUser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
var sbutton = $("sbutton");
sbutton.onclick=function(event)
{
sOnClick();
};
}
function bOnClick()
{
springUser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
在web.xml中加入
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/classes/applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
運行服務器輸入http://localhost:8080/DWRStudy/springUserInfo.html，可以看到運行結果
主要的區別是dwr.xml的配置，需要在creator=spring,然后里面的<param>的name用beanName,值是spring的配置文件里的bean的id。Name=location是指定spring的配置文件的路徑（如果不指定DWR可以根據web.xml自動找到spring的主配置文件）。
DWR的Annotation配置
還是上面spring那個例子的功能再來一遍(new 的配置太簡單)，這樣的話項目中的dwr.xml對于這個例子就沒有作用了
新建User類（包名換了）
Java代碼
package org.li.dwr.spring.annotation;
import java.util.List;
import org.directwebremoting.annotations.Convert;
import org.directwebremoting.annotations.Create;
import org.directwebremoting.annotations.Param;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProperty;
import org.directwebremoting.convert.BeanConverter;
import org.directwebremoting.spring.SpringCreator;
import org.li.dwr.Book;
@Create(creator=SpringCreator.class,name="anspringuser",creatorParams={@Param(name="beanName",value="anuser"),@Param(name="location",value="applicationContext.xml")})
@Convert(converter=BeanConverter.class)
public class User
{
private String welcome;
private String username;
@RemoteProperty
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
@RemoteMethod
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
package org.li.dwr.spring.annotation;
import java.util.List;
import org.directwebremoting.annotations.Convert;
import org.directwebremoting.annotations.Create;
import org.directwebremoting.annotations.Param;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProperty;
import org.directwebremoting.convert.BeanConverter;
import org.directwebremoting.spring.SpringCreator;
import org.li.dwr.Book;
@Create(creator=SpringCreator.class,name="anspringuser",creatorParams={@Param(name="beanName",value="anuser"),@Param(name="location",value="applicationContext.xml")})
@Convert(converter=BeanConverter.class)
public class User
{
private String welcome;
private String username;
@RemoteProperty
private String address;
private List<Book> books;
private int age;
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public int getAge()
{
return age;
}
public void setAge(int age)
{
this.age = age;
}
public String getUsername()
{
return username;
}
public void setUsername(String username)
{
this.username = username;
}
public String getWelcome()
{
return welcome;
}
public void setWelcome(String welcome)
{
this.welcome = welcome;
}
public List<Book> getBooks()
{
return books;
}
public void setBooks(List<Book> books)
{
this.books = books;
}
@RemoteMethod
public User getUser(String welcome)
{
this.welcome=welcome;
return this;
}
}
新建過濾器類DWRAnLog
Java代碼
package org.li.dwr.log.annotation;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilter;
import org.directwebremoting.AjaxFilterChain;
import org.directwebremoting.annotations.Filter;
import org.directwebremoting.filter.SpringTransactionAjaxFilter;
@Filter(type=SpringTransactionAjaxFilter.class)
public class DWRAnLog implements AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("annotation過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method, params);
}
}
package org.li.dwr.log.annotation;
import java.lang.reflect.Method;
import org.directwebremoting.AjaxFilter;
import org.directwebremoting.AjaxFilterChain;
import org.directwebremoting.annotations.Filter;
import org.directwebremoting.filter.SpringTransactionAjaxFilter;
@Filter(type=SpringTransactionAjaxFilter.class)
public class DWRAnLog implements AjaxFilter
{
public Object doFilter(Object obj, Method method, Object[] params, AjaxFilterChain chain) throws Exception
{
System.out.println("annotation過濾器Log輸出:..對象："+obj.getClass().getName()+"方法："+method.getName());
return chain.doFilter(obj, method, params);
}
}
在spring的applicationContext.xml里加入
Java代碼
<bean id="anuser" class="org.li.dwr.spring.annotation.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
<bean id="anuser" class="org.li.dwr.spring.annotation.User">
<property name="username">
<value>javafish</value>
</property>
<property name="age">
<value>21</value>
</property>
<property name="address">
<value>北京市海淀區</value>
</property>
</bean>
新建AnSpringUserInfoHtml.html
Java代碼
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/anspringuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="anspringuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>UserInfo.html</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<script type='text/javascript' src='dwr/interface/anspringuser.js'></script>
<script type='text/javascript' src='dwr/engine.js'></script>
<script type='text/javascript' src='dwr/util.js'></script>
<script type="text/javascript" src="anspringuserInfo.js"></script>
</head>
<body>
請輸入你的名字：
<input id="name" type="text"/>
<input id="jbutton" type="button" value="得到javafish(spring)的信息"/>
<div id="result"></div>
<script>load()</script>
</body>
</html>
新建anspringuserInfo.js
Java代碼
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
}
function bOnClick()
{
alert("haha");
anspringuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
function load()
{
var jbutton = $("jbutton");
jbutton.onclick=function(event)
{
bOnClick();
};
}
function bOnClick()
{
alert("haha");
anspringuser.getUser($("name").value,callback);
}
function callback(msg)
{
var user = msg;
DWRUtil.setValue('result',"歡迎你！"+user.welcome+" 姓名："+user.username+",年齡："+user.age+"，住址："+user.address);
}
在web.xml中
的DWR的servlet的初始化參數里加入
Java代碼
<init-param>
<param-name>classes</param-name>
<param-value>
org.li.dwr.log.annotation.DWRAnLog,org.li.dwr.spring.annotation.User
</param-value>
</init-param>
<init-param>
<param-name>classes</param-name>
<param-value>
org.li.dwr.log.annotation.DWRAnLog,org.li.dwr.spring.annotation.User
</param-value>
</init-param>
運行服務器輸入http://localhost:8080/DWRStudy/AnSpringUserInfo.html，成功了
用Annotation的配置和dwr.xml的意思基本一樣，這里就不多做介紹了。
Util.js的函數庫
$()和prototype.js一樣相當于document.getElementById
(Set)getValue（）(設置)得到元素的值一般是（設置）得到元素的innerHTML。
getText()得到元素的文本值
(set)getValues()（設置）得到元素下的元素，以array為對象載體。
這里都是一些最常用的函數，具體可以看一下util.js文件。
總結
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