Spring-Lesson3

spring整合JDBC

spring提供了很多模板整合Dao技术

spring中提供了一个可以操作数据库的对象.对象封装了jdbc技术.

JDBCTemplate => JDBC模板对象

与DBUtils中的QueryRunner非常相似.

//0 准备连接池
ComboPooledDataSource dataSource = new ComboPooledDataSource();
dataSource.setDriverClass("com.mysql.jdbc.Driver");
dataSource.setJdbcUrl("jdbc:mysql:///hibernate_32");
dataSource.setUser("root");
dataSource.setPassword("root");
//1 创建JDBC模板对象
JdbcTemplate jt = new JdbcTemplate();
jt.setDataSource(dataSource);
//2 书写sql,并执行
String sql = "insert into t_user values(null,'rose') ";
jt.update(sql);

步骤

导包

4+2---->
spring-beans-4.2.4.RELEASE.jar
spring-context-4.2.4.RELEASE.jar
spring-core-4.2.4.RELEASE.jar
spring-expression-4.2.4.RELEASE.jar
com.springsource.org.apache.commons.logging-1.1.1.jar
com.springsource.org.apache.log4j-1.2.15.jar
spring-aop---->
spring-aop-4.2.4.RELEASE.jar
junit4类库/spring-test---->
spring-test-4.2.4.RELEASE.jar
c3p0连接池---->
com.springsource.com.mchange.v2.c3p0-0.9.1.2.jar
JDBC驱动---->
mysql-connector-java-5.1.7-bin.jar
spring-jdbc---->
spring-jdbc-4.2.4.RELEASE.jar
spring-tx事务---->
spring-tx-4.2.4.RELEASE.jar

书写Dao

增删改查

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.jdbc.core.support.JdbcDaoSupport;

import cn.itcast.bean.User;
//使用JDBC模板实现增删改查 模板是依赖于连接池的
public class UserDaoImpl extends JdbcDaoSupport implements UserDao {
    @Override
    public void save(User u) {
        String sql = "insert into t_user values(null,?) ";
        super.getJdbcTemplate().update(sql, u.getName());
    }
    @Override
    public void delete(Integer id) {
        String sql = "delete from t_user where id = ? ";
        super.getJdbcTemplate().update(sql,id);
    }
    @Override
    public void update(User u) {
        String sql = "update  t_user set name = ? where id=? ";
        super.getJdbcTemplate().update(sql, u.getName(),u.getId());
    }
    @Override
    public User getById(Integer id) {
        String sql = "select * from t_user where id = ? ";
        return super.getJdbcTemplate().queryForObject(sql,new RowMapper<User>(){
            @Override
            public User mapRow(ResultSet rs, int arg1) throws SQLException {
                User u = new User();
                u.setId(rs.getInt("id"));
                u.setName(rs.getString("name"));
                return u;
            }}, id);
        
    }
    @Override
    public int getTotalCount() {
        String sql = "select count(*) from t_user  ";
        Integer count = super.getJdbcTemplate().queryForObject(sql, Integer.class);
        return count;
    }

    @Override
    public List<User> getAll() {
        String sql = "select * from t_user  ";
        List<User> list = super.getJdbcTemplate().query(sql, new RowMapper<User>(){
            @Override
            public User mapRow(ResultSet rs, int arg1) throws SQLException {
                User u = new User();
                u.setId(rs.getInt("id"));
                u.setName(rs.getString("name"));
                return u;
            }});
        return list;
    }
}

spring配置

依赖关系

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-4.2.xsd 
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-4.2.xsd ">

    <!-- 指定spring读取db.properties配置 -->
    <context:property-placeholder location="classpath:db.properties" />

    <!-- 1.将连接池放入spring容器 -->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="user" value="${jdbc.user}"></property>
        <property name="password" value="${jdbc.password}"></property>
    </bean>

    <!-- 2.将JDBCTemplate放入spring容器 -->
    <bean name="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="dataSource"></property>
    </bean>

    <!-- 3.将UserDao放入spring容器 -->
    <bean name="userDao" class="cn.itcast.a_jdbctemplate.UserDaoImpl">
        <!-- <property name="jt" ref="jdbcTemplate" ></property> -->
        <property name="dataSource" ref="dataSource"></property>
    </bean>

</beans>

测试

import java.beans.PropertyVetoException;

import javax.annotation.Resource;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import com.mchange.v2.c3p0.ComboPooledDataSource;

import cn.itcast.bean.User;

//演示JDBC模板
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class Demo {
        @Resource(name="userDao")
    private UserDao ud;
    
    @Test
    public void fun1() throws Exception{
        
        //0 准备连接池
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql:///hibernate_32");
        dataSource.setUser("root");
        dataSource.setPassword("root");
        //1 创建JDBC模板对象
        JdbcTemplate jt = new JdbcTemplate();
        jt.setDataSource(dataSource);
        //2 书写sql,并执行
        String sql = "insert into t_user values(null,'rose') ";
        jt.update(sql);
        
    }
    
    @Test
    public void fun2() throws Exception{
        User u = new User();
        u.setName("tom");
        ud.save(u);
    }
    @Test
    public void fun3() throws Exception{
        User u = new User();
        u.setId(2);
        u.setName("jack");
        ud.update(u);
        
    }
    
    @Test
    public void fun4() throws Exception{
        ud.delete(2);
    }
    
    @Test
    public void fun5() throws Exception{
        System.out.println(ud.getTotalCount());
    }
    
    @Test
    public void fun6() throws Exception{
        System.out.println(ud.getById(1));
    }
    
    @Test
    public void fun7() throws Exception{
        System.out.println(ud.getAll());
    }
    
}

---

spring中aop事务

事务

事务特性:acid

原子性（Atomicity）
一致性（Consistency）
隔离性（Isolation）
持久性（Durability）

事务并发问题

脏读
不可重复读
幻读

事务的隔离级别

1 读未提交
2 读已提交
4 可重复读
8 串行化

spring封装了事务管理代码

事务操作
打开事务
提交事务/回滚事务

事务操作对象

因为在不同平台,操作事务的代码各不相同.spring提供了一个接口

PlatformTransactionManager 接口
DataSourceTransactionManager
HibernateTransitionmanager

注意:在spring中玩事务管理.最为核心的对象就是TransactionManager对象

spring管理事务的属性介绍

事务的隔离级别

1 读未提交
2 读已提交
4 可重复读
8 串行化

是否只读

true 只读
false 可操作

事务的传播行为

spring管理事务方式

编码式

1.将核心事务管理器配置到spring容器

<!-- 事务核心管理器,封装了所有事务操作. 依赖于连接池 -->
<bean name="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager" >
    <property name="dataSource" ref="dataSource" ></property>
</bean>

2.配置TransactionTemplate模板

<!-- 事务模板对象 -->
<bean name="transactionTemplate" class="org.springframework.transaction.support.TransactionTemplate" >
    <property name="transactionManager" ref="transactionManager" ></property>
</bean>

3.将事务模板注入Service

<bean name="accountService" class="cn.itcast.service.AccountServiceImpl" >
    <property name="ad" ref="accountDao" ></property>
    <property name="tt" ref="transactionTemplate" ></property>
</bean>  

4.在Service中调用模板

@Override
public void transfer(final Integer from,final Integer to,final Double money) {
            //减钱
            ad.decreaseMoney(from, money);
//                int i = 1/0;
            //加钱
            ad.increaseMoney(to, money);
}

xml配置(aop)

1.导包

com.springsource.org.aopalliance-1.0.0.jar
spring-aspects-4.2.4.RELEASE.jar
com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar

2.导入新的约束(tx)

beans: 最基本
context:读取properties配置
aop:配置aop
tx:配置事务通知

3.配置通知

<!-- 配置事务通知 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager" >
    <tx:attributes>
        <!-- 以方法为单位,指定方法应用什么事务属性
            isolation:隔离级别
            propagation:传播行为
            read-only:是否只读
         -->
        <tx:method name="save*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
        <tx:method name="persist*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
        <tx:method name="update*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
        <tx:method name="modify*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
        <tx:method name="delete*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
        <tx:method name="remove*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
        <tx:method name="get*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="true" />
        <tx:method name="find*" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="true" />
        <tx:method name="transfer" isolation="REPEATABLE_READ" propagation="REQUIRED" read-only="false" />
    </tx:attributes>
</tx:advice>

4.配置将通知织入目标

<!-- 配置织入 -->
<aop:config  >
    <!-- 配置切点表达式 -->
    <aop:pointcut expression="execution(* cn.itcast.service.*ServiceImpl.*(..))" id="txPc"/>
    <!-- 配置切面 : 通知+切点
             advice-ref:通知的名称
             pointcut-ref:切点的名称
     -->
    <aop:advisor advice-ref="txAdvice" pointcut-ref="txPc" />
</aop:config>

注解配置(aop)

3.开启注解管理事务

<!-- 开启使用注解管理aop事务  这个配置替代了上面的配置通知，和将通知织入目标的操作 只要去代码中用注解操作即可  -->
<tx:annotation-driven/>

 4.使用注解

@Transactional(isolation=Isolation.REPEATABLE_READ,propagation=Propagation.REQUIRED,readOnly=true)
public class AccountServiceImpl implements AccountService {

    private AccountDao ad ;
    private TransactionTemplate tt;
    
    @Override
    @Transactional(isolation=Isolation.REPEATABLE_READ,propagation=Propagation.REQUIRED,readOnly=false)
    public void transfer(final Integer from,final Integer to,final Double money) {
                //减钱
                ad.decreaseMoney(from, money);
//                int i = 1/0;
                //加钱
                ad.increaseMoney(to, money);
    }

    public void setAd(AccountDao ad) {
        this.ad = ad;
    }

    public void setTt(TransactionTemplate tt) {
        this.tt = tt;
    }
}