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Struts 学习笔记2(输入校验、国际化、异常处理)

發布時間：2024/1/17 编程问答 22 豆豆

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項目文件結構

項目源文件下載地址：http://dl.dbank.com/c05qyg3yir

Struts2的輸入校驗

Struts2輸入校驗、執行流程：

1）首先進行類型轉換

2）然后進行輸入校驗（執行validate方法）

3）如果在上述過程中出現了任何錯誤，都不會再去執行 execute方法，會轉向 struts.xml 中該 action 的名為 input 的 result 所對應的頁面。

要點：

1. ActionSupport 類的 addActionError()方法的實現：首先創建一個ArrayList對象，然后將錯誤消息添加到該 ArrayList對象中。

2. 當調用 getActionErrors()方法返回 Action 級別的錯誤信息列表時，返回的實際上是集合的一個副本而不是集合本身，因此對集合副本調用 clear()方法清除的依舊是副本中的元素而非原集合中的元素，此時原集合中的內容沒有收到任何的影響。換句話說，Action級別的錯誤信息列表對開發者來說是只讀的。

3. Field Error 級別的錯誤信息底層是用 LinkedHashMap 實現的，該Map 的 key 是 String 類型，value 是 List<String>類型，這就表示一個 Field Name 可以對應多條錯誤信息，這些錯誤信息都放置在List<String>集合當中。

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<%@ taglib prefix="s" uri="/struts-tags" %>

………………………………

<body>

<s:actionerror cssStyle="color:red"/>

----------------------------------------

<s:fielderror cssStyle="color:blue"></s:fielderror>

<!--

username: <input type="text" name="username" size="20"><br>

password: <input type="password" name="password" size="20"><br>

repassword: <input type="password" name="repassword" size="20"><br>

age: <input type="text" name="age" size="20"><br>

birthday: <input type="text" name="birthday" size="20"><br>

graduation: <input type="text" name="graduation" size="20"><br>

</form>

-->

<s:form action="register.action" theme="simple"><!—-加theme="simple修飾以簡單表單呈現-->

username: <s:textfield name="username" label="username"></s:textfield><br>

password: <s:password name="password" label="password"></s:password><br>

repassword: <s:password name="repassword" label="repassword"></s:password><br>

age: <s:textfield name="age" label="age"></s:textfield><br>

birthday: <s:textfield name="birthday" label="birthday"></s:textfield><br>

graduation: <s:textfield name="graduation" label="graduation"></s:textfield><br>

<s:submit value="submit"></s:submit>

</s:form>

</body>

</html>

RegisterAction.java

package com.shengsiyuan.struts2;

import java.util.Calendar;

import java.util.Date;

import com.opensymphony.xwork2.ActionSupport;

public class RegisterAction extends ActionSupport

{

????private String username;

????private String password;

????private String repassword;

????private int age;

????private Date birthday;

????private Date graduation;

????public String getUsername()

????{

????????return username;

????}

????public void setUsername(String username)

????{

????????this.username = username;

????}

????public String getPassword()

????{

????????return password;

????}

????public void setPassword(String password)

????{

????????this.password = password;

????}

????public String getRepassword()

????{

????????return repassword;

????}

????public void setRepassword(String repassword)

????{

????????this.repassword = repassword;

????}

????public int getAge()

????{

????????return age;

????}

????public void setAge(int age)

????{

????????this.age = age;

????}

????public Date getBirthday()

????{

????????return birthday;

????}

????public void setBirthday(Date birthday)

????{

????????this.birthday = birthday;

????}

????public Date getGraduation()

????{

????????return graduation;

????}

????public void setGraduation(Date graduation)

????{

????????this.graduation = graduation;

????}

????@Override

????public String execute() throws Exception

????{

????????return SUCCESS;

????}

????@Override

????public void validate()

????{

????????if(null == username || username.length() < 4 || username.length() > 6)

????????{

????????????this.addActionError("username invalid");????//Action級別的錯誤

????????????this.addFieldError("username", "username invalid in field");//field級別的錯誤

????????}

????????if(null == password || password.length() < 4 || password.length() > 6)

????????{

????????????this.addActionError("password invalid");

????????}

????????else if(null == repassword || repassword.length() < 4 || repassword.length() > 6)

????????{

????????????this.addActionError("repassword invalid");

????????}

????????else if(!password.equals(repassword))

????????{

????????????this.addActionError("the passwords not the same");

????????}

????????if(age < 10 || age > 50)

????????{

????????????this.addActionError("age invalid");

????????}

????????if(null == birthday)

????????{

????????????this.addActionError("birthday invalid");

????????}

????????if(null == graduation)

????????{

????????????this.addActionError("graduation invalid");

????????}

????????if(null != birthday && null != graduation)

????????{

????????????Calendar c1 = Calendar.getInstance();????//獲取日期

????????????c1.setTime(birthday);

????????????

????????????Calendar c2 = Calendar.getInstance();

????????????c2.setTime(graduation);

????????????

????????????if(!c1.before(c2)) //如果c1不在c2前

????????????{

????????????????this.addActionError("birthday should be before graduation");

????????????}

????????}

????????//this.getFieldErrors().clear();????//clear()方法清空的只是副本

????????//this.getActionErrors().clear();

????????//this.clearActionErrors();????//清除Action級別的錯誤消息

????????//this.clearFieldErrors();????//清除field級別的錯誤消息

????????System.out.println("invoked!!!");

????}

}

struts.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE struts PUBLIC

"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"

"http://struts.apache.org/dtds/struts-2.0.dtd">

????<package name="struts2" extends="struts-default">

???? ?

????????<action name="login" class="com.shengsiyuan.struts2.LoginAction" method="myExecute">????

????????????<result name="success">/result.jsp</result>

????????</action>

????????

????????<action name="userAction" class="com.shengsiyuan.struts2.UserAction">

????????????<result name="success">/output.jsp</result>

????????</action>

????????

????????<action name="userAction2" class="com.shengsiyuan.struts2.UserAction2">

????????????<result name="success">/output.jsp</result>

????????</action>

????????

????????<action name="register" class="com.shengsiyuan.struts2.RegisterAction">

????????????<result name="success">/registerResult.jsp</result>

????????????<result name="input">/register.jsp</result>

????????</action>

????</package>

</struts>

截圖

提交之前截圖

以html標簽提交之后的截圖

以struts標簽，且未加theme="simple"屬性提交的結果

若使用<s:form action="register.action" theme="simple">則呈現的結果同以html提交一樣。不管是Action級別的，還是field級別的，在執行excute方法時，只要對應的錯誤容器中有錯誤消息，則轉到input對應的頁面，如果容器中沒有錯誤消息，則繼續往下執行。

----------------------------------------------------------

在tomcat中手動添加web項目：

????…………

</Host>

</Engine>

</Service>

</Server>

java.lang.ClassNotFoundException: javax.el.ELResolver錯誤解決方法：Remove of classpath server-api.jar and jsp-api.jar

-------------------------------------------------------------

Action級別的自定義方法的輸入校驗

要點：

1. Action中自定義方法的輸入校驗。對于通過action的method屬性所指定的自定義方法，其對應的自定義輸入校驗方法名為validateMyExecute（假設自定義的方法名為 myExecute）。底層是通過反射來調用的。

2. 當在Action中指定了自定義的 execute方法時，首先會執行自定義的 execute 方法所對應的輸入校驗方法，然后再去執行標準的 validate 方法，執行完畢后如果出現了任何錯誤都不會再去執行自定義的execute方法，流程轉向了 input這個名字所對應的頁面上。

…………

<body>

username: <input type="text" name="username"><br>

password: <input type="password" name="password"><br>

age: <input type="text" name="age"><br>

date: <input type="text" name="date"><br>

</form>

</body>

</html>

LoginAction

package com.shengsiyuan.struts2;

import java.util.Date;

import com.opensymphony.xwork2.ActionSupport;

import com.shengsiyuan.exception.PasswordException;

import com.shengsiyuan.exception.UsernameException;

public class LoginAction extends ActionSupport

{

????private String username;

????private String password;

????private int age;

????private Date date;

????

????public Date getDate()

????{

????????return date;

????}

????public void setDate(Date date)

????{

????????this.date = date;

????}

????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 getPassword()

????{

????????return password;

????}

????public void setPassword(String password)

????{

????????this.password = password;

????}

????

????public String execute() throws Exception

????{

????????if(!"hello".equals(username))

????????{

????????????throw new UsernameException("username invalid");

????????}

????????if(!"world".equals(password))

????????{

????????????throw new PasswordException("password invalid");

????????}

????????return SUCCESS;

????}

????

????//自定的execute方法，在struts.xml中指定了LoginAction中的method方法為myExecute

????public String myExecute() throws Exception

????{

????????System.out.println("myExecute invoked!!");

????????return SUCCESS;

????}

????

????//Action自定義方法的輸入校驗

????public void validateMyExecute()????//此驗證方法規定為將myExecute()方法名首字母大寫后，再加前綴validate構成

????{

????????System.out.println("validateMyExecute invoked!!");

????????this.addActionError("action error");

????}

????

????@Override

????public void validate()

????{

????????//System.out.println("validate invoked!");

????????//this.addActionError("action error");

????}

}

注：如果去除了struts.xml文件中的method="myExecute"，則對應的自定義的校驗方法將無效。

????<result name="success">/result.jsp</result>

</action>

自定義Field級別的錯誤提示消息

要點：

1）新建一個以 Action 名命名的 properties 文件，如RegisterAction.properties。屬性文件名要求為對應的Action文件名字。

2）然后在該屬性文件中指定每一個出錯字段的錯誤消息 invalid.fieldvalue.birthday=birthday invalid !!

Tip: jdk提供的一款中文轉換為unicode編碼的工具,在jdk的bin目錄下，native2ascii。在命令行下使用，使用方法如下：

struts2校驗框架

要點：

Struts2的校驗框架（有效的xml文件）。具體來說分為字段優先校驗器與校驗器優先校驗器。

配置文件的命名規則為：要對哪個Action加入校驗框架，即在此個Action所在的包下添加一個名字為 xxxActioh-validation.xml文件。比如給RegisterAction用校驗框架校驗，則在RegiterAction對應的包下，添加一個名為RegisterAction-validation.xml的文件.

注釋掉Action當中的校驗方法與自定義的校驗方法，配置Action的execute方法為默認的execute方法。

Struts2框架校驗執行的先后順序：

1）首先執行校驗框架（xml文件）

2）執行自定義方法的校驗方法（validateMyExecute）

3）執行validate方法

對于struts.xml文件的結果配置來說，局部要優于全局。

xwork-validator.xml

<?xml version="1.0" encoding="UTF-8"?>

<!--

XWork Validators DTD.

Used the following DOCTYPE.

<!DOCTYPE validators PUBLIC

????????"-//OpenSymphony Group//XWork Validator 1.0.2//EN"

????????"http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

-->

<!ELEMENT validators (field|validator)+><!—字段優先與校驗器優先兩種-->

<!ELEMENT field (field-validator+)>

<!ATTLIST field

????name CDATA #REQUIRED

<!ELEMENT field-validator (param*, message)>

<!ATTLIST field-validator

????type CDATA #REQUIRED

short-circuit (true|false) "false"

<!ELEMENT validator (param*, message)>

<!ATTLIST validator

????type CDATA #REQUIRED

short-circuit (true|false) "false"

<!ELEMENT param (#PCDATA)>

<!ATTLIST param

name CDATA #REQUIRED

<!ELEMENT message (#PCDATA)>

<!ATTLIST message

key CDATA #IMPLIED

RegisterAcion-validation.xml

字段優先校驗

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

????<field name="username">

????????<field-validator type="requiredstring">

????????????<param name="trim">false</param>

????????????<message>username can't be blank!</message>

????????</field-validator>

????????<field-validator type="stringlength">

????????????<param name="minLength">4</param>

????????????<param name="maxLength">6</param>

????????????<param name="trim">false</param>

????????????<!—讀取屬性文件，使用國際化，當校驗失敗提示的錯誤消息 --

????????????<message key="username.invalid"></message>>

????????</field-validator>

????</field>

????

????<field name="password">

????????<field-validator type="requiredstring">

????????????<message>password can't be blank!</message>

????????</field-validator>

????????<field-validator type="stringlength">

????????????<param name="minLength">4</param>

????????????<param name="maxLength">6</param>

????????????<message>length of password should be between ${minLength} and ${maxLength}</message>

????????</field-validator>

????</field>

????

????<field name="age">

????????<field-validator type="required">

????????????<message>age can't be blank!</message>

????????</field-validator>

????????<field-validator type="int">

????????????<param name="min">10</param>

????????????<param name="max">40</param>

????????????<!—在這里可以用${元素名} 引用上面的子元素-->

????????????<message>age should be between ${min} and ${max}</message>

????????</field-validator>

????</field>

????

????<field name="birthday">

????????<field-validator type="required">

????????????<message>birthday can't be blank!</message>

????????</field-validator>

????????<field-validator type="date">

????????????<param name="min">2005-1-1</param>

????????????<param name="max">2007-12-31</param>

????????????<message>birthday should be between ${min} and ${max}</message>

????????</field-validator>

????</field>

</validators>

校驗器優先校驗（混合）

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE validators PUBLIC "-//OpenSymphony Group//XWork Validator 1.0.2//EN" "http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">

????<validator type="requiredstring">

????????<param name="fieldName">username</param>

????????<message>username can't be blank!</message>

????</validator>

????

????<validator type="stringlength">

????????<param name="fieldName">username</param>

????????<param name="minLength">4</param>

????????<param name="maxLength">6</param>

????????<!—在這里可以用${元素名} 引用上面的子元素-->

????????<message>length of username should be between ${minLength} and ${maxLength}</message>

????</validator>

????

????<field name="birthday">

????????<field-validator type="required">

????????????<message>birthday can't be blank!</message>

????????</field-validator>

????????<field-validator type="date">

????????????<param name="min">2005-1-1</param>

????????????<param name="max">2007-12-31</param>

????????????<message>birthday should be between ${min} and ${max}</message>

????????</field-validator>

????</field>

</validators>

打開com.opensymphony.xwork2.validator.validators可以發現一個default.xml文件，打開可以發現其中定義了各種校驗器，內容如下：

default.xml

<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE validators PUBLIC

"-//OpenSymphony Group//XWork Validator Config 1.0//EN"

"http://www.opensymphony.com/xwork/xwork-validator-config-1.0.dtd">

</validators>

錯誤消息國際化

在Action所在的包下建立兩個屬性文件，名字分別叫：

package_en_US.properties

username.invalid=username invalid

package_zh_CN.properties

username.invalid=\u7528\u6237\u540D\u4E0D\u5408\u6CD5\uFF01

#用戶名不合法

運行結果截圖

Struts2國際化

對于國際化的資源文件，其命名規則是： package_語言名_國家名，比如package_zh_CN，package_en_US 。

I18NTest1.java

package com.shengsiyuan.i18n;

import java.util.Locale;

public class I18NTest1

{

????public static void main(String[] args)

????{

????????Locale[] locales = Locale.getAvailableLocales();

????????for (Locale locale : locales)

????????{

????????????System.out.println(locale.getDisplayCountry() + " : "

????????????????????+ locale.getCountry());????????//顯示國家及國家代碼

//????????????System.out.println(locale.getDisplayLanguage() + " : " + locale.getLanguage());

????????}

????}

}

I18Ntest2.java

在src目錄(classpath)下,建立三個資源文件，分別如下(注 i18n即為資源文件的base name)：

i18n_en_US.properties

hello=hello\:{0}

i18n_zh_CN.properties

hello=\u4F60\u597D\uFF1A{0}

i18n.properties

hello=hello world

I18Ntest2.java代碼如下：

package com.shengsiyuan.i18n;

import java.util.Locale;

import java.util.ResourceBundle;

public class I18NTest2

{

????public static void main(String[] args)

????{

????????System.out.println(Locale.getDefault());

????????//綁定一個base name 為i18n的資源文件，Locale使用FRANCE(法國)

????????ResourceBundle bundle = ResourceBundle.getBundle("i18n", Locale.FRANCE);

????????//獲取hello字符串的值

????????String value = bundle.getString("hello");

????????System.out.println(value);

????}

}

I18Ntest3.java(傳入參數)

package com.shengsiyuan.i18n;

import java.text.MessageFormat;

import java.util.Locale;

import java.util.ResourceBundle;

public class I18NTest3

{

????public static void main(String[] args)

????{

????????Locale locale = Locale.CHINA;????//將locale定義為CHINA

????????//綁定到資源文件

????????ResourceBundle bundle = ResourceBundle.getBundle("i18n", locale);

????????//獲取資源文件中的字符串對象

????????String value = bundle.getString("hello");

????????//格式化字符串對象，并傳入參數，后邊的Object數組對象表示要插入到占位符上的具體的對象

????????String result = MessageFormat.format(value, new Object[]{"維唯為為"});

????????System.out.println(result);

????}

}

注意：調整瀏覽器的語言和字符編碼選項后，要注意，程序中輸入的日期格式，也要做相應的改變，不然會出現日期類型轉換錯誤。字符串國際化的同時，也要注意，日期的國際化。

Struts2異常處理及全局異常與結果

要點：

我們既可以在 Action 中定義異常與結果，也可以定義全局的異常與結果，局部總是優于全局的，如果定義成全局，那么可以為所有的 Action 所公用，而局部的異常與結果只能被當前的 Action 所獨享，不能為其他Action所共享。

validate主要進行沒有業務邏輯的驗證，比如判斷用戶名長名、密碼與重復密碼是否相同等。而判斷用戶登錄是否成功，

struts2異常處理實例

在第三層建一個包，取名exception ,并在包中建兩個類，分別取名為：

PasswordException.java

package com.shengsiyuan.exception;

public class UsernameException extends Exception

{

????private String message;

????public UsernameException(String message)

????{

????????super(message);

????????this.message = message;

????}

????public String getMessage()

????{

????????return message;

????}

????public void setMessage(String message)

????{

????????this.message = message;

????}

}

UsernameException.java

package com.shengsiyuan.exception;

public class PasswordException extends Exception

{

????private String message;

????public PasswordException(String message)

????{

????????super(message);

????????this.message = message;

????}

????public String getMessage()

????{

????????return message;

????}

????public void setMessage(String message)

????{

????????this.message = message;

????}

}

編輯loginAction的execute方法

????public String execute() throws Exception

????{

????????if(!"hello".equals(username))

????????{

????????????throw new UsernameException("username invalid");

????????}

????????if(!"world".equals(password))

????????{

????????????throw new PasswordException("password invalid");

????????}

????????return SUCCESS;

????}

編輯struts.xml文件

Struts2的處理局部異常機制

…………

????<package name="struts2" extends="struts-default">

????????<action name="login" class="com.shengsiyuan.struts2.LoginAction">

????????????<exception-mapping result="usernameInvalid" exception="com.shengsiyuan.exception.UsernameException"></exception-mapping>

????????????<exception-mapping result="passwordInvalid" exception="com.shengsiyuan.exception.PasswordException"></exception-mapping>

????????????

????????????<result name="usernameInvalid">/usernameInvalid.jsp</result>

????????????<result name="passwordInvalid">/passwordInvalid.jsp</result>

????????????<result name="success">/result.jsp</result>

????????</action>

????………………

</struts>

Struts2的處理全局異常機制

…………

????<package name="struts2" extends="struts-default">

????????<global-results>

????????????<result name="usernameInvalid">/usernameInvalid.jsp</result>

????????????<result name="passwordInvalid">/passwordInvalid.jsp</result>

????????</global-results>

????????<global-exception-mappings>

????????????<exception-mapping result="usernameInvalid" exception="com.shengsiyuan.exception.UsernameException"></exception-mapping>

????????????<exception-mapping result="passwordInvalid" exception="com.shengsiyuan.exception.PasswordException"></exception-mapping>

????????</global-exception-mappings>

????………………

</struts>

轉載于:https://www.cnblogs.com/luowei010101/archive/2012/02/07/2340764.html

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