Spring 事务
Spring事务控制原理
Spring使用动态代理，为业务DAO类或Service类添加事务管理的切面方法。
Spring 事务
注解事务使用@Transactional
1、方法级别的事务，会覆盖类级别的事务
2、注解@Transactional在类上面，对类的所有方法都有效
3、@Transactional(isolation=Isolation.DEFAULT,propagation=Propagation.REQUIRED,readOnly=false)在方法上，表明方法对数据库可写
4、@Transactional(readOnly=true)在方法上，表明方法对数据库只读
代码片段
java
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
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.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.0.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd">
<context:component-scan base-package="com.hk.eshop"/>
<!--配置DBCP数据库连接池-->
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="com.mysql.jdbc.Driver"/>
<property name="url" value="jdbc:mysql://localhost:3306/test01?useUnicode=true&characterEncoding=utf8"/>
<property name="username" value="root"/>
<property name="password" value="root"/>
<!--连接池中初始化连接数量-->
<property name="initialSize" value="1"/>
<!--连接池中连接数量最大值-->
<property name="maxActive" value="500"/>
<!--连接池中连接最大空闲连接数-->
<property name="maxIdle" value="2"/>
<!--连接池中连接最小空闲连接数-->
<property name="minIdle" value="1"/>
</bean>
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>
<bean id="userMng" class="com.hk.eshop.jdbc.UserMng">
<property name="jdbcTemplate" ref="jdbcTemplate"/>
</bean>
<aop:aspectj-autoproxy proxy-target-class="true"/>
<bean id="trManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<!-- 扫描标注事务注解的方法,由事务管理器托管 -->
<tx:annotation-driven transaction-manager="trManager"/>
</beans>
package com.hk.eshop.jdbc;
public class UserInfo {
private String id = null;
private String name = null;
private String pwd = null;
private String email = null;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
package com.hk.eshop.jdbc;
import java.util.List;
public interface IUserMng {
public void saveUser(UserInfo ui);
public void updateUser(UserInfo ui);
public void deleteById(String id);
public UserInfo getUser(String id);
public List<UserInfo> find();
}
package com.hk.eshop.jdbc;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.jdbc.core.JdbcTemplate;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Isolation;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
@Transactional(readOnly=true)
public class UserMng implements IUserMng{
private JdbcTemplate jdbcTemplate;
public JdbcTemplate getJdbcTemplate() {
return jdbcTemplate;
}
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
@Transactional(isolation= Isolation.DEFAULT,propagation= Propagation.REQUIRED,readOnly=false)
public void saveUser(UserInfo ui)
{
String sql = "insert into spring_user(id,name,pwd,email) values (?,?,?,?)";
Object [] args = {ui.getId(),ui.getName(),ui.getPwd(),ui.getEmail()};
int [] argTypes = {java.sql.Types.VARCHAR,java.sql.Types.VARCHAR,
java.sql.Types.VARCHAR,java.sql.Types.VARCHAR};
jdbcTemplate.update(sql, args,argTypes);
}
@Transactional(isolation=Isolation.DEFAULT,propagation=Propagation.REQUIRED,readOnly=false)
public void updateUser(UserInfo ui)
{
String sql = "update spring_user set name=?,pwd=?,email=? where id=?";
Object [] args = {ui.getName(),ui.getPwd(),ui.getEmail(),ui.getId()};
jdbcTemplate.update(sql, args);
}
@Transactional(isolation=Isolation.DEFAULT,propagation=Propagation.REQUIRED,readOnly=false)
public void deleteById(String id)
{
String sql = "delete from spring_user where id=?";
Object [] args = {id};
jdbcTemplate.update(sql, args);
}
public UserInfo getUser(String id)
{
String sql = "select id,name,pwd,email from spring_user where id=?";
Object [] args = {id};
RowMapper<UserInfo> rowMapper = new RowMapper<UserInfo>() {
public UserInfo mapRow(ResultSet rs, int rowNum) throws SQLException {
UserInfo ui = new UserInfo();
ui.setId(rs.getString("id"));
ui.setName(rs.getString("name"));
ui.setPwd(rs.getString("pwd"));
ui.setEmail(rs.getString("email"));
return ui;
}
};
try {
UserInfo ui = jdbcTemplate.queryForObject(sql, args, rowMapper);
return ui;
}
catch(EmptyResultDataAccessException e)
{
return null;
}
}
public List<UserInfo> find()
{
String sql = "select id,name,pwd,email from spring_user";
RowMapper<UserInfo> rowMapper = new RowMapper<UserInfo>() {
public UserInfo mapRow(ResultSet rs, int rowNum) throws SQLException {
UserInfo ui = new UserInfo();
ui.setId(rs.getString("id"));
ui.setName(rs.getString("name"));
ui.setPwd(rs.getString("pwd"));
ui.setEmail(rs.getString("email"));
return ui;
}
};
List<UserInfo> list = jdbcTemplate.query(sql, rowMapper);
return list;
}
}
package com.hk.eshop.jdbc;
import java.util.List;
import javax.sql.DataSource;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) throws Exception
{
//UserInfo ui = new UserInfo();
ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
UserMng um = (UserMng)ac.getBean("userMng");
UserInfo ui = new UserInfo();
ui.setId("1");
ui.setName("Android");
ui.setPwd("pwd");
ui.setEmail("java@test.com");
um.saveUser(ui);
System.out.println("saveUser############ ui.id="+ui.getId()+",ui.name="+ui.getName());
UserInfo ui2 = um.getUser("0");
System.out.println("getUser############ ui2.id="+ui2.getId()+",ui2.name="+ui2.getName());
List<UserInfo> lst = um.find();
System.out.println("find############ lst.size()="+lst.size());
um.deleteById("1");
System.out.println("deleteById############");
List<UserInfo> lst2 = um.find();
System.out.println("find############ lst2.size()="+lst2.size());
}
}
package com.hk.eshop.jdbc;
import java.util.List;
import javax.annotation.Resource;
import javax.sql.DataSource;
import junit.framework.TestCase;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
@RunWith(value=SpringJUnit4ClassRunner.class)
@ContextConfiguration(value="classpath:beans.xml")
public class UserMngTest extends TestCase {
@Resource(name="userMng")
IUserMng userMng;
@Test
public void testDataSource(){
ApplicationContext ac = new ClassPathXmlApplicationContext("beans.xml");
DataSource dataSource = (DataSource)ac.getBean("dataSource");
System.out.println("testDataSource dataSource:"+dataSource);
}
@Test
public void saveUser(){
//查询全部表记录
List<UserInfo> lst = userMng.find();
int size = lst.size();
//添加一条数据库记录
UserInfo ui = new UserInfo();
ui.setId("0");
ui.setName("java");
ui.setPwd("pwd");
ui.setEmail("java@test.com");
userMng.saveUser(ui);
List<UserInfo> lst2 = userMng.find();
if(lst2.size() != (size+1)) fail("userMng.saveUser()方法测试失败");
}
@Test
public void updateUser(){
UserInfo ui = new UserInfo();
ui.setId("0");
ui.setName("android");
ui.setPwd("888");
ui.setEmail("android@test.com");
userMng.updateUser(ui);
//查询id=0记录,比较字段是否修改正确
UserInfo chkUi = userMng.getUser("0");
if(!chkUi.getName().equals(ui.getName()) ||
!chkUi.getPwd().equals(ui.getPwd()) ||
!chkUi.getEmail().equals(ui.getEmail()))
{
fail("userMng.updateUser()方法测试失败");
}
}
@Test
public void deleteUser(){
//通过ID删除
String id = "0";
userMng.deleteById(id);
UserInfo chkUi = userMng.getUser(id);
if(chkUi != null) fail("userMng.updateUser()方法测试失败");
}
@Test
public void getUser(){
String id = "0";
UserInfo user = userMng.getUser(id);
System.out.println("getUser user="+user);
}
@Test
public void find(){
List<UserInfo> lst2 = userMng.find();
System.out.println("find lst2.size()="+lst2.size());
}
}出现此错误
Exception in thread "main" java.lang.ClassCastException: com.sun.proxy.$Proxy6 cannot be cast to com.hk.eshop.jdbc.UserMng
at com.hk.eshop.jdbc.Main.main(Main.java:16)
是因为aop代理配置缺少属性proxy-target-class="true"
