1.創(chuàng)建項目,項目名稱hibernatedemo26,目錄結(jié)構(gòu)如圖所示

2.在項目中創(chuàng)建lib目錄存儲jar文件,目錄結(jié)構(gòu)如圖所示

3.在src目錄中創(chuàng)建實體類Forum,包名(com.mycompany.demo.bean),如圖所示

4.實體類Forum的內(nèi)容如下

package?com.mycompany.demo.bean;import?java.util.Set;public?class?Forum?{private?int?fid;private?String?name;private?Set<ForumPost>?forumPosts;public?int?getFid()?{return?fid;}public?void?setFid(int?fid)?{this.fid?=?fid;}public?String?getName()?{return?name;}public?void?setName(String?name)?{this.name?=?name;}public?Set<ForumPost>?getForumPosts()?{return?forumPosts;}public?void?setForumPosts(Set<ForumPost>?forumPosts)?{this.forumPosts?=?forumPosts;} }

5.在src目錄中創(chuàng)建實體類Forum的映射文件Forum.hbm.xml,包名(com.mycompany.demo.bean),如圖所示

6.映射文件Forum.hbm.xml的內(nèi)容如下

<?xml?version="1.0"?encoding="utf-8"?> <!DOCTYPE?hibernate-mapping?PUBLIC?"-//Hibernate/Hibernate?Mapping?DTD//EN""http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">?<!--package:指定<class/>所在的包?--> <hibernate-mapping?package="com.mycompany.demo.bean"><!--name:類名table:表名?catalog:數(shù)據(jù)庫名稱,默認為hibernate.cfg.xml中配置的數(shù)據(jù)庫名稱--><class?name="Forum"?table="forum"><meta?attribute="class-description">This?class?contains?the?forum?detail.?</meta><!--name:屬性名colum:列名?--><id?name="fid"?type="int"?column="fid"><!--increment:hibernate維護主鍵值identity:數(shù)據(jù)庫自增長sequence:序列native:根據(jù)不同的數(shù)據(jù)庫選擇生成策略uuid:通過UUID算法生成,實際使用較多assigned:手工設(shè)置--><generator?class="native"/></id><!--length:字節(jié)長度type:字段類型,支持java和hibernate類型not-null:非空約束unique:唯一性約束--><property?name="name"?column="name"?/><!--lazy:false:直接加載true:延遲加載extra:特別延遲加載fetchjoin:迫切左外連接select:普通select查詢subselect?:子查詢方式--><set?name="forumPosts"><key?column="fid"/><one-to-many?class="ForumPost"/></set></class> </hibernate-mapping>

7.在src目錄中創(chuàng)建實體類ForumPost,包名(com.mycompany.demo.bean),如圖所示

8.實體類ForumPost的內(nèi)容如下

package?com.mycompany.demo.bean;public?class?ForumPost?{private?int?pid;private?String?subject;private?Forum?forum;public?int?getPid()?{return?pid;}public?void?setPid(int?pid)?{this.pid?=?pid;}public?String?getSubject()?{return?subject;}public?void?setSubject(String?subject)?{this.subject?=?subject;}public?Forum?getForum()?{return?forum;}public?void?setForum(Forum?forum)?{this.forum?=?forum;} }

9.在src目錄中創(chuàng)建實體類ForumPost的映射文件ForumPost.hbm.xml,包名(com.mycompany.demo.bean),如圖所示

10.映射文件ForumPost.hbm.xml的內(nèi)容如下

<?xml?version="1.0"?encoding="utf-8"?> <!DOCTYPE?hibernate-mapping?PUBLIC?"-//Hibernate/Hibernate?Mapping?DTD//EN""http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">?<!--package:指定<class/>所在的包?--> <hibernate-mapping?package="com.mycompany.demo.bean"><!--name:類名table:表名?catalog:數(shù)據(jù)庫名稱,默認為hibernate.cfg.xml中配置的數(shù)據(jù)庫名稱--><class?name="ForumPost"?table="forumpost"><meta?attribute="class-description">This?class?contains?the?forumpost?detail.?</meta><!--name:屬性名colum:列名?--><id?name="pid"?type="int"?column="pid"><!--increment:hibernate維護主鍵值identity:數(shù)據(jù)庫自增長sequence:序列native:根據(jù)不同的數(shù)據(jù)庫選擇生成策略uuid:通過UUID算法生成,實際使用較多assigned:手工設(shè)置--><generator?class="native"/></id><!--length:字節(jié)長度type:字段類型,支持java和hibernate類型not-null:非空約束unique:唯一性約束--><property?name="subject"?column="subject"?type="string"?length="50"?not-null="true"?unique="false"/><!--name:關(guān)聯(lián)屬性?column:關(guān)聯(lián)屬性在數(shù)據(jù)庫對應(yīng)的字段class:關(guān)聯(lián)屬性所對應(yīng)的類型--><many-to-one?name="forum"?class="Forum"?column="fid"?cascade="save-update"?fetch="join"/></class><query?name="queryAll">from?Forum?f?left?outer?join?fetch?f.forumPosts</query> </hibernate-mapping>

11.在src目錄中創(chuàng)建工具類 HbnUtil,包名(com.mycompany.demo.util),如圖所示

12.工具類?HbnUtil的內(nèi)容如下

package?com.mycompany.demo.util;import?org.hibernate.Session; import?org.hibernate.SessionFactory; import?org.hibernate.cfg.Configuration;public?class?HbnUtil?{private?static?SessionFactory?sessionFactory;public?static?Session?getSession(){if(sessionFactory?==?null?||?sessionFactory.isClosed()){sessionFactory?=?new?Configuration().configure().buildSessionFactory();}return?sessionFactory.getCurrentSession();} }

13.在src目錄中創(chuàng)建Hibernate的配置文件hibernate.cfg.xml,如圖所示

14.Hibernate的配置文件hibernate.cfg.xml的內(nèi)容如下

<?xml?version="1.0"?encoding="utf-8"?> <!DOCTYPE?hibernate-configuration?SYSTEM? "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><hibernate-configuration><session-factory><!--?方言,可以從Hibernate核心jar(hibernate-core-x.x.x.Finall.jar)文件中的or.hibernate.dialect包中找到相應(yīng)的類,類的全名就是?--><property?name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property><!--?驅(qū)動?--><property?name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property><!--?數(shù)據(jù)庫連接地址?--><property?name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property><!--?用戶名?--><property?name="hibernate.connection.username">root</property><!--?密碼?--><property?name="hibernate.connection.password"></property><!--create:每次都新創(chuàng)建,如果存在就刪除create-drop:創(chuàng)建新表,sessionFactory關(guān)閉,表會刪除update?:表字段增加,會同步,字段減少不同步,數(shù)據(jù)改變會同步修改--><property?name="hibernate.hbm2ddl.auto">update</property><!--?輸出sql?--><property?name="hibernate.show_sql">true</property><!--?格式化sql?--><property?name="hibernate.format_sql">true</property><!--?事務(wù)環(huán)境一個線程對一個事務(wù)thread:本地事務(wù)環(huán)境jta:分布式事務(wù)環(huán)境SpringSessionContext:用于ssh整合--><property?name="hibernate.current_session_context_class">thread</property> ??<!--?使用c3p0數(shù)據(jù)源?--><property?name="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</property>?<!--?List?of?XML?mapping?files?--><mapping?resource="com/mycompany/demo/bean/Forum.hbm.xml"/><mapping?resource="com/mycompany/demo/bean/ForumPost.hbm.xml"/> </session-factory> </hibernate-configuration>

15.在項目中創(chuàng)建test目錄存儲測試文件,文件名稱TestApp,包名(com.mycompany.demo.bean),目錄結(jié)構(gòu)如圖所示

16.TestApp測試類的內(nèi)容如下

package?com.mycompany.demo.bean;import?java.util.HashSet; import?java.util.List; import?java.util.Set;import?org.hibernate.Criteria; import?org.hibernate.Session; import?org.hibernate.sql.JoinType; import?org.junit.Before; import?org.junit.Test;import?com.mycompany.demo.util.HbnUtil;public?class?TestApp?{private?Session?session;@Beforepublic?void?init(){session?=?HbnUtil.getSession();}/**?一對多雙向關(guān)聯(lián)-添加*?需要設(shè)置Forum.hbm.xml中的Set屬性為cascade="all"*/@Testpublic?void?testOneToManyAdd(){try?{session.beginTransaction();ForumPost?forumPost1?=?new?ForumPost();forumPost1.setSubject("A");ForumPost?forumPost2?=?new?ForumPost();forumPost2.setSubject("B");Set<ForumPost>?forumPosts?=?new?HashSet<ForumPost>();forumPosts.add(forumPost1);forumPosts.add(forumPost2);Forum?forum?=?new?Forum();forum.setName("foruma");forum.setForumPosts(forumPosts);session.save(forum);session.getTransaction().commit();}?catch?(Exception?e)?{session.getTransaction().rollback();e.printStackTrace();}}/**?多對一雙向關(guān)聯(lián)-fetch="join"*/@Testpublic?void?testFetchForJoin(){try?{session.beginTransaction();ForumPost?forumPost?=?session.get(ForumPost.class,?10);Forum?forum?=?forumPost.getForum();System.out.println(forum.getFid());System.out.println(forum.getName());session.getTransaction().commit();}?catch?(Exception?e)?{session.getTransaction().rollback();e.printStackTrace();}} }

轉(zhuǎn)載于:https://blog.51cto.com/suyanzhu/1913073

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