Spring框架第六篇之Spring与DAO

一、Spring与JDBC模板

1、搭建环境

首先导入需要的jar包：

以上jar中多导入了DBCP和C3P0的jar包，因为这里需要演示怎么配置多种数据源，所以导入了这两个包，在实际开发中无需导入这两个包。

2、数据源的配置

数据源的配置分为3中情况：

1、Spring内置的连接池DriverManagerDataSource；

2、DBCP数据源 BasicDataSource；

3、C3P0数据源 ComboPooledDataSource；

具体在XML中的配置如下：

<?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:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
           http://www.springframework.org/schema/aop
           http://www.springframework.org/schema/aop/spring-aop-2.5.xsd">

    <!-- 注册数据源：1、Spring内置连接池 -->
    <!--<bean id="myDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/test"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>-->

    <!-- 注册数据源：2、DBCP -->
    <!--<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/test"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>-->

    <!-- 注册数据源：3、C3P0 -->
    <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://127.0.0.1:3306/test"/>
        <property name="user" value="root"/>
        <property name="password" value="root"/>
    </bean>

    <!-- 注册JdbcTemplate -->
    <bean id="myJdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="myDataSource"/>
    </bean>

    <!-- 注册Dao -->
    <bean id="studentDao" class="com.ietree.spring.dao.basic.dao.StudentDaoImpl">
        <property name="jdbcTemplate" ref="myJdbcTemplate"/>
    </bean>

    <!-- 注册Service -->
    <bean id="studentService" class="com.ietree.spring.dao.basic.service.StudentServiceImpl">
        <property name="dao" ref="studentDao"/>
    </bean>

</beans>

3、从属性文件读取数据库连接信息

创建db.properties数据库配置文件：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/test
jdbc.user=root
jdbc.password=root

配置Spring配置文件：

<!-- 注册数据源：3、C3P0 -->
    <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--注册属性文件：方式一-->
    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:db.properties"/>
    </bean>

    <!--注册属性文件：方式二-->
    <context:property-placeholder location="classpath:db.properties"/>

4、配置JDBC模板

<bean id="myJdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
     <property name="dataSource" ref="myDataSource"/>
</bean>
<!-- 注册Dao -->
<bean id="studentDao" class="com.ietree.spring.dao.basic.dao.StudentDaoImpl">
     <property name="jdbcTemplate" ref="myJdbcTemplate"/>
</bean>

5、DAO实现类继承JdbcDaoSupport类，对数据库的增删改查操作

package com.ietree.spring.dao.basic.dao;

import com.ietree.spring.dao.basic.bean.Student;
import com.ietree.spring.dao.basic.bean.StudentRowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;

import java.util.List;

/**
 * Created by Root on 2017/7/9.
 */
public class StudentDaoImpl extends JdbcDaoSupport implements IStudentDao {

    @Override
    public void insertStudent(Student student) {
        String sql = "INSERT INTO tbl_student(name,age) VALUES(?,?)";
        this.getJdbcTemplate().update(sql,student.getName(),student.getAge());
    }

    @Override
    public void deleteStudent(int id) {
        String sql = "DELETE FROM tbl_student WHERE id = ?";
        this.getJdbcTemplate().update(sql,id);
    }

    @Override
    public void updateStudent(Student student) {
        String sql = "UPDATE tbl_student SET name=?,age=? WHERE id = ?;";
        this.getJdbcTemplate().update(sql,student.getName(),student.getAge(),student.getId());
    }

    @Override
    public List<String> selectAllStudentNames() {
        String sql = "SELECT name FROM tbl_student";
        return this.getJdbcTemplate().queryForList(sql,String.class);
    }

    @Override
    public String selectStudentNameById(int id) {
        String sql = "SELECT name FROM tbl_student WHERE id = ?";
        return this.getJdbcTemplate().queryForObject(sql,String.class,id);
    }

    @Override
    public List<Student> selectAllStudent() {
        String sql = "SELECT id,name,age FROM tbl_student";
        return this.getJdbcTemplate().query(sql, new StudentRowMapper());
    }

    @Override
    public Student selectStudentById(int id) {
        String sql = "SELECT id,name,age FROM tbl_student WHERE id = ?";
        return this.getJdbcTemplate().queryForObject(sql, new StudentRowMapper(),id);
    }
}

StudentRowMapper类：

package com.ietree.spring.dao.basic.bean;

import org.springframework.jdbc.core.RowMapper;

import java.sql.ResultSet;
import java.sql.SQLException;

/**
 * Created by Root on 2017/7/11.
 */
public class StudentRowMapper implements RowMapper<Student> {

    /**
     * 这里的rs代表的是查询出来的结果中的一行数据，并非代表所有数据。只要能执行到这个方法，就说明rs不可能为空
     */
    @Override
    public Student mapRow(ResultSet rs, int rowNum) throws SQLException {
        Student student = new Student();
        student.setId(rs.getInt("id"));
        student.setName(rs.getString("name"));
        student.setAge(rs.getInt("age"));
        return student;
    }
}

以上案例完整的配置文件如下：

<?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">

    <!-- 注册数据源：1、Spring内置连接池 -->
    <!--<bean id="myDataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/test"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>-->

    <!-- 注册数据源：2、DBCP -->
    <!--<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://127.0.0.1:3306/test"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
    </bean>-->

    <!-- 注册数据源：3、C3P0 -->
    <!--<bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="com.mysql.jdbc.Driver"/>
        <property name="jdbcUrl" value="jdbc:mysql://127.0.0.1:3306/test"/>
        <property name="user" value="root"/>
        <property name="password" value="root"/>
    </bean>-->

    <!-- 注册数据源：3、C3P0 -->
    <bean id="myDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.user}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <!--注册属性文件：方式一-->
    <!--<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location" value="classpath:db.properties"/>
    </bean>-->

    <!--注册属性文件：方式二-->
    <context:property-placeholder location="classpath:db.properties"/>

    <!-- 根据JdbcDaoSupport类的源码可以省略JdbcTemplate的注册，将DataSource作为Dao的属性 -->
    <!-- 注册JdbcTemplate -->
    <bean id="myJdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="myDataSource"/>
    </bean>
    <!-- 注册Dao -->
    <bean id="studentDao" class="com.ietree.spring.dao.basic.dao.StudentDaoImpl">
        <property name="jdbcTemplate" ref="myJdbcTemplate"/>
    </bean>

    <!-- 注册Dao -->
    <bean id="studentDao" class="com.ietree.spring.dao.basic.dao.StudentDaoImpl">
        <property name="dataSource" ref="myDataSource"/>
    </bean>

    <!-- 注册Service -->
    <bean id="studentService" class="com.ietree.spring.dao.basic.service.StudentServiceImpl">
        <property name="dao" ref="studentDao"/>
    </bean>

</beans>

二、Spring的事务管理

1、Spring事务管理API

2、使用Spring的事务代理工厂管理事务

3、使用Spring的事务注解管理事务

4、使用AspectJ的AOP配置管理事务