一 配置文件

二 DAO

1 接口

package org.crazyit.app.dao;public interface NewsDao{   public void insert(String title, String content);}

2 实现类

package org.crazyit.app.dao.impl;import javax.sql.DataSource;import java.sql.Connection;import org.springframework.jdbc.core.JdbcTemplate;import org.springframework.transaction.annotation.*;import org.crazyit.app.dao.*;public class NewsDaoImpl implements NewsDao{  private DataSource ds;  public void setDs(DataSource ds)  {    this.ds = ds;  }  @Transactional(propagation=Propagation.REQUIRED ,    isolation=Isolation.DEFAULT , timeout=5)  public void insert(String title, String content)  {    JdbcTemplate jt = new JdbcTemplate(ds);    jt.update("insert into news_inf"      + " values(null , ? , ?)"      , title , content);    // 两次插入的数据违反唯一键约束    jt.update("insert into news_inf"      + " values(null , ? , ?)"      , title , content);    // 如果没有事务控制，则第一条记录可以被插入    // 如果增加事务控制，将发现第一条记录也插不进去。  }}

三 测试类

package lee;import org.springframework.context.support.*;import org.springframework.context.*;import org.crazyit.app.dao.*;public class SpringTest{  public static void main(String[] args)  {    // 创建Spring容器    ApplicationContext ctx = new      ClassPathXmlApplicationContext("beans.xml");    // 获取事务代理Bean    NewsDao dao = (NewsDao)ctx      .getBean("newsDaoTrans" , NewsDao.class);    // 执行插入操作    dao.insert("疯狂Java" , "轻量级Java EE企业应用实战");  }}

四 测试

数据库没生成数据，说明事务生效。

Exception in thread "main" org.springframework.dao.DuplicateKeyException: PreparedStatementCallback; SQL [insert into news_inf values(null , ? , ?)]; Duplicate entry '疯狂Java' for key 'news_title'; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '疯狂Java' for key 'news_title' at org.springframework.jdbc.support.SQLErrorCodeSQLExceptionTranslator.doTranslate(SQLErrorCodeSQLExceptionTranslator.java:239) at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:73) at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:660) at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:909) at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:970) at org.springframework.jdbc.core.JdbcTemplate.update(JdbcTemplate.java:980) at org.crazyit.app.dao.impl.NewsDaoImpl.insert(NewsDaoImpl.java:33) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:317) at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:98) at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:262) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:95) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:207) at com.sun.proxy.$Proxy4.insert(Unknown Source) at lee.SpringTest.main(SpringTest.java:28)Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry '疯狂Java' for key 'news_title' at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at com.mysql.jdbc.Util.handleNewInstance(Util.java:409) at com.mysql.jdbc.Util.getInstance(Util.java:384) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1039) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4232) at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4164) at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2615) at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2776) at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2838) at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2082) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2334) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2262) at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2246) at com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeUpdate(NewProxyPreparedStatement.java:147) at org.springframework.jdbc.core.JdbcTemplate$2.doInPreparedStatement(JdbcTemplate.java:916) at org.springframework.jdbc.core.JdbcTemplate$2.doInPreparedStatement(JdbcTemplate.java:909) at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:644) ... 18 more