JdbcTemplate基本使用
01-JdbcTemplate基本使用-概述(了解)
①导入spring-jdbc和spring-tx坐标
②创建数据库表和实体
③创建JdbcTemplate对象
④执行数据库操作
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.yh</groupId>
<artifactId>spring_day4</artifactId>
<version>1.0-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.0.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.0.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>5.0.8.RELEASE</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.46</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.10</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>5.0.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.8.13</version>
</dependency>
</dependencies>
</project>
创建数据库表和实体
package com.yh.domain;
public class Account {
private String name;
private double money;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public double getMoney() {
return money;
}
public void setMoney(double money) {
this.money = money;
}
@Override
public String toString() {
return "Account{" +
"name='" + name + '\'' +
", money=" + money +
'}';
}
}
执行数据库操作
@Test
//测试JdbcTemplate开发步骤
public void test1() throws PropertyVetoException {
//创建数据源对象
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql://localhost:3306/test");
dataSource.setUser("root");
dataSource.setPassword("root");
JdbcTemplate jdbcTemplate = new JdbcTemplate();
//设置数据源对象 知道数据库在哪
jdbcTemplate.setDataSource(dataSource);
//执行操作
int row = jdbcTemplate.update("insert into account(name,money) values(?,?)", "李赛博", 5000);
System.out.println(row);
}
<!--数据源对象-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="com.mysql.jdbc.Driver"></property>
<property name="jdbcUrl" value="jdbc:mysql:///test"></property>
<property name="user" value="root"></property>
<property name="password" value="root"></property>
</bean>
<!--jdbc模板对象-->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>
测试代码
@Test
//测试Spring产生jdbcTemplate对象
public void test2() throws PropertyVetoException {
ApplicationContext app = new ClassPathXmlApplicationContext("applicationContext.xml");
JdbcTemplate jdbcTemplate = app.getBean(JdbcTemplate.class);
int row = jdbcTemplate.update("insert into account(name,account) values(?,?)", "lisi", 5000);
System.out.println(row);
}
jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=root
配置文件修改为:
<?xml version="1.0" encoding="UTF-8"?>
<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"
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.xsd
">
<!--加载jdbc.properties-->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!--数据源对象-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${jdbc.url}"/>
<property name="user" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<!--jdbc模板对象-->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
<property name="dataSource" ref="dataSource"/>
</bean>
</beans>
package com.yh.test;
import com.yh.domain.Account;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.util.List;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {
@Autowired
private JdbcTemplate jdbcTemplate;
//修改更新
@Test
public void testUpdate(){
jdbcTemplate.update("update account set money=? where name=?",10000,"tom");
}
//删除
@Test
public void testDelete(){
jdbcTemplate.update("delete from account where name=?","tom");
}
}
package com.yh.test;
import com.yh.domain.Account;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import java.util.List;
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class JdbcTemplateCRUDTest {
@Autowired
private JdbcTemplate jdbcTemplate;
//聚合查询
@Test
public void testQueryCount(){
Long count = jdbcTemplate.queryForObject("select count(*) from account", Long.class);
System.out.println(count);
}
//查询一个
@Test
public void testQueryOne(){
Account account = jdbcTemplate.queryForObject("select * from account where name=?", new BeanPropertyRowMapper<Account>(Account.class), "tom");
System.out.println(account);
}
//查询所有
@Test
public void testQueryAll(){
List<Account> accountList = jdbcTemplate.query("select * from account", new BeanPropertyRowMapper<Account>(Account.class));
System.out.println(accountList);
}
}
①导入spring-jdbc和spring-tx坐标
③创建JdbcTemplate对象
JdbcTemplate jdbcTemplate = newJdbcTemplate();
jdbcTemplate.setDataSource(dataSource);
④执行数据库操作
更新操作:
jdbcTemplate.update (sql,params)
查询操作:
jdbcTemplate.query (sql,Mapper,params)
jdbcTemplate.queryForObject(sql,Mapper,params)
注意:
PlatformTransactionManager 是接口类型,不同的 Dao 层技术则有不同的实现类,例如:Dao 层技术是jdbc 或 mybatis 时:org.springframework.jdbc.datasource.DataSourceTransactionManager
Dao 层技术是hibernate时:org.springframework.orm.hibernate5.HibernateTransactionManager
-
-
ISOLATION_READ_UNCOMMITTED
-
ISOLATION_READ_COMMITTED
-
ISOLATION_REPEATABLE_READ
-
-
-
SUPPORTS:支持当前事务,如果当前没有事务,就以非事务方式执行(没有事务)
-
MANDATORY:使用当前的事务,如果当前没有事务,就抛出异常
-
REQUERS_NEW:新建事务,如果当前在事务中,把当前事务挂起。
-
NOT_SUPPORTED:以非事务方式执行操作,如果当前存在事务,就把当前事务挂起
-
NEVER:以非事务方式运行,如果当前存在事务,抛出异常
-
NESTED:如果当前存在事务,则在嵌套事务内执行。如果当前没有事务,则执行 REQUIRED 类似的操作
-
超时时间:默认值是-1,没有超时限制。如果有,以秒为单位进行设置
-
TransactionStatus 接口提供的是事务具体的运行状态,方法介绍如下。
1.4 知识要点
编程式事务控制三大对象
-
PlatformTransactionManager
-
TransactionDefinition
-
TransactionStatus
2.1 什么是声明式事务控制
Spring 的声明式事务顾名思义就是采用声明的方式来处理事务。这里所说的声明,就是指在配置文件中声明,用在 Spring 配置文件中声明式的处理事务来代替代码式的处理事务。
-
事务管理不侵入开发的组件。具体来说,业务逻辑对象就不会意识到正在事务管理之中,事实上也应该如此,因为事务管理是属于系统层面的服务,而不是业务逻辑的一部分,如果想要改变事务管理策划的话,也只需要在定义文件中重新配置即可
-
在不需要事务管理的时候,只要在设定文件上修改一下,即可移去事务管理服务,无需改变代码重新编译,这样维护起来极其方便
注意:Spring 声明式事务控制底层就是AOP。
声明式事务控制明确事项:
-
谁是切点?
-
谁是通知?
-
配置切面?
①引入tx命名空间
<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:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
http://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
②配置事务增强
<!--平台事务管理器-->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource"></property>
</bean>
<!--事务增强配置-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
Dao层和对应的实现:
public interface AccountDao {
//减钱
public void decreate(Long from,Long money);
//加钱
public void increate(Long to,Long money);
}
@Repository
public class AccountDaoImpl implements AccountDao {
@Autowired
private JdbcTemplate jdbcTemplate;
public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
this.jdbcTemplate = jdbcTemplate;
}
@Override
public void decreate(Long from, Long money) {
jdbcTemplate.update("update tb_account set account=money-? where id=?",money,from);
}
@Override
public void increate(Long to, Long money) {
jdbcTemplate.update("update tb_account set account=money+? where id=?",money,to);
}
}
Service层对应的接口和实现
public interface AccountService {
//转账
public void transfer(Long from,Long to,Long money);
}
@Service
public class AccountServiceImpl implements AccountService {
@Autowired
private AccountDao accountDao;
@Override
public void transfer(Long from, Long to, Long money) {
accountDao.decreate(from,money);
accountDao.increate(to,money);
}
}
③配置事务 AOP 织入
<!--事务的aop增强-->
<aop:config>
<aop:pointcut id="myPointcut" expression="execution(* com.yh.service.impl.*.*(..))"/>
<aop:advisor advice-ref="txAdvice" pointcut-ref="myPointcut"></aop:advisor>
</aop:config>
测试正常转账遇到的错误
[14:06:27:291] [WARN ] [RMI TCP Connection(3)-127.0.0.1] [org.springframework.web.context.support.XmlWebApplicationContext] [Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [spring/spring-core.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.support.DefaultBeanFactoryPointcutAdvisor#0': Cannot resolve reference to bean 'txPoint' while setting bean property 'pointcut'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'txPoint': Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.aop.aspectj.AspectJExpressionPointcut] from ClassLoader [ParallelWebappClassLoader
context: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@1c4af82c
]]
[14:06:27:312] [ERROR] [RMI TCP Connection(3)-127.0.0.1] [org.springframework.web.context.ContextLoader] [Context initialization failed]
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [spring/spring-core.xml]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.aop.support.DefaultBeanFactoryPointcutAdvisor#0': Cannot resolve reference to bean 'txPoint' while setting bean property 'pointcut'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'txPoint': Lookup method resolution failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.aop.aspectj.AspectJExpressionPointcut] from ClassLoader [ParallelWebappClassLoader
context: ROOT
delegate: false
----------> Parent Classloader:
java.net.URLClassLoader@1c4af82c
]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:519)
at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:401)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:292)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:103)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4716)
at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5177)
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:717)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:690)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:706)
at org.apache.catalina.startup.HostConfig.manageApp(HostConfig.java:1727)
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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:288)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:459)
at org.apache.catalina.mbeans.MBeanFactory.createStandardContext(MBeanFactory.java:408)
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.apache.tomcat.util.modeler.BaseModelMBean.invoke(BaseModelMBean.java:288)
at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.invoke(DefaultMBeanServerInterceptor.java:819)
at com.sun.jmx.mbeanserver.JmxMBeanServer.invoke(JmxMBeanServer.java:801)
at com.sun.jmx.remote.security.MBeanServerAccessController.invoke(MBeanServerAccessController.java:468)
at javax.management.remote.rmi.RMIConnectionImpl.doOperation(RMIConnectionImpl.java:1468)
at javax.management.remote.rmi.RMIConnectionImpl.access$300(RMIConnectionImpl.java:76)
at javax.management.remote.rmi.RMIConnectionImpl$PrivilegedOperation.run(RMIConnectionImpl.java:1309)
at java.security.AccessController.doPrivileged(Native Method)
at javax.management.remote.rmi.RMIConnectionImpl.doPrivilegedOperation(RMIConnectionImpl.java:1408)
at javax.management.remote.rmi.RMIConnectionImpl.invoke(RMIConnectionImpl.java:829)
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 sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:324)
解决导入缺少 切面相关的依赖
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>1.9.6</version>
</dependency>
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjweaver</artifactId>
<version>1.9.6</version>
</dependency>
<dependency>
<groupId>org.aopalliance</groupId>
<artifactId>com.springsource.org.aopalliance</artifactId>
<version>1.0.0</version>
</dependency>
④测试事务控制转账业务代码
@Override
public void transfer(Long from, Long to, Long money) {
accountDao.decreate(from,money);
int i = 1/0;
accountDao.increate(to,money);
}
<!--事务增强配置-->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<tx:method name="*"/>
</tx:attributes>
</tx:advice>
<tx:method name="transfer" isolation="REPEATABLE_READ" propagation="REQUIRED" timeout="-1" read-only="false"/>
-
-
isolation:事务的隔离级别
-
propogation:事务的传播行为
-
timeout:超时时间
-
2.4 知识要点
声明式事务控制的配置要点
-
平台事务管理器配置
-
事务通知的配置
-
事务aop织入的配置
@Repository("accountDao")
public class AccountDaoImpl implements AccountDao {
@Autowired
private JdbcTemplate jdbcTemplate;
public void out(String outMan, double money) {
jdbcTemplate.update("update account set money=money-? where name=?",money,outMan);
}
public void in(String inMan, double money) {
jdbcTemplate.update("update account set money=money+? where name=?",money,inMan);
}
}
2.编写 AccoutService
@Service("accountService")
@Transactional
public class AccountServiceImpl implements AccountService {
@Autowired
private AccountDao accountDao;
@Transactional(isolation = Isolation.READ_COMMITTED,propagation = Propagation.REQUIRED)
public void transfer(String outMan, String inMan, double money) {
accountDao.out(outMan,money);
int i = 1/0;
accountDao.in(inMan,money);
}
}
3.编写 applicationContext.xml 配置文件
<!—之前省略datsSource、jdbcTemplate、平台事务管理器的配置-->
<!--组件扫描-->
<context:component-scan base-package="com.yh"/>
<!--事务的注解驱动-->
<tx:annotation-driven/>
①使用 @Transactional 在需要进行事务控制的类或是方法上修饰,注解可用的属性同 xml 配置方式,例如隔离级别、传播行为等。
②注解使用在类上,那么该类下的所有方法都使用同一套注解参数配置。
③使用在方法上,不同的方法可以采用不同的事务参数配置。
④Xml配置文件中要开启事务的注解驱动<tx:annotation-driven />
3.3 知识要点
注解声明式事务控制的配置要点
-
平台事务管理器配置(xml方式)
-
事务通知的配置(@Transactional注解配置)
-
事务注解驱动的配置 tx:annotation-driven/
注意:本文归作者所有,未经作者允许,不得转载