Spring实战——使用注解实现声明式事务

Bertha 。 2021-07-24 21:55 373阅读 0赞

**一 配置文件**

<?xml version="1.0" encoding="GBK"?>
    <beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://www.springframework.org/schema/beans"
         xmlns:p="http://www.springframework.org/schema/p"
         xmlns:aop="http://www.springframework.org/schema/aop"
         xmlns:tx="http://www.springframework.org/schema/tx"
         xsi:schemaLocation="http://www.springframework.org/schema/beans
         http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
         http://www.springframework.org/schema/aop
         http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
         http://www.springframework.org/schema/tx
         http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
         
         <bean id="dataSource"  class="com.mchange.v2.c3p0.ComboPooledDataSource"
               destroy-method="close"
               p:driverClass="com.mysql.jdbc.Driver"
               p:jdbcUrl="jdbc:mysql://localhost/spring"
               p:user="root"
               p:password="32147"
               p:maxPoolSize="40"
               p:minPoolSize="2"
               p:initialPoolSize="2"
               p:maxIdleTime="30"/>
         
         <bean id="newsDao"  class="org.crazyit.app.dao.impl.NewsDaoImpl"
               p:ds-ref="dataSource"/>
         
         
         
         <bean id="transactionManager"
               class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
               p:dataSource-ref="dataSource"/>
         
         <tx:annotation-driven  transaction-manager="transactionManager"/>
    </beans>

**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