spring框架学习笔记6：JDBC模板

JDBC模板：Spring中对数据库的操作。

这一部分对熟悉DBUtils的QueryRunner的开发者来说，非常简单

这是以前我简单写的dbutils的知识：

http://www.cnblogs.com/xuyiqing/p/8397428.html

导包：

1.spring中的包

2.c3p0连接池包

3.数据库驱动包

最终导入这些包：

2.准备数据库测试：

简单的测试：

    @Test
    public void fun1() throws Exception{

        //准备连接池
        ComboPooledDataSource dataSource = new ComboPooledDataSource();
        dataSource.setDriverClass("com.mysql.jdbc.Driver");
        dataSource.setJdbcUrl("jdbc:mysql:///mybase");
        dataSource.setUser("root");
        dataSource.setPassword("xuyiqing");
        //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,'Tom') ";
        jt.update(sql);

    }

接下来使用Spring框架管理对象：

创建实体类：

package bean;

public class User {
    private Integer id;
    private String name;
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + "]";
    }

}

数据库操作功能：

package jdbctemplate;

import java.util.List;

import bean.User;

public interface UserDao {

    //增
    void save(User u);
    //删
    void delete(Integer id);
    //改
    void update(User u);
    //查
    User getById(Integer id);
    //查
    int getTotalCount();
    //查
    List<User> getAll();
}

package 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.jdbc.core.support.JdbcDaoSupport;

import bean.User;
//使用JDBC模板实现增删改查
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;
    }

}

现在就完成了数据库操作，接下来配置到Spring来管理对象

注意配置文件：

先写一个键值对配置文件：db.properties

jdbc.jdbcUrl=jdbc:mysql:///mybase
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.user=root
jdbc.password=xuyiqing

xml配置文件：

<?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UserDao放入spring容器 -->
<bean name="userDao" class="jdbctemplate.UserDaoImpl" >
    <property name="dataSource" ref="dataSource" ></property>
</bean>

</beans>

测试：

package jdbctemplate;

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 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 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());
    }

}