1 Spring整合JDBC模版

1.1 spring中土拱了一个可以操作数据库的对象。对象封装了jdbc技术

JDBCTemplateJDBC模板对象

1.2 与DBUtils中的QueryRunner非常相似

1.3 准备工作

1.导包 4+2 基础包+日志包。 junit5+spring-test、spring-aop、c3p0连接池、JDBC驱动、spring-jdbc、spring-tx事务

JDBC演示

1.4 JDBC模版实现增删改查操作

准备接口UserDao

编写实现类 UserDaoImpl

增

删

改

查

主配置文件applicationContext.xml

测试

1.5 代码优化

1.6 spring整合JDBC --读取properties配置

准备properties文件

主要代码提供参考(下面是优化之前的代码)

UserDao接口

package com.legend.a_jdbctemplate;

import java.util.List;

import com.legend.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);//通过ID
    int getTotalCount();//查找总记录数
    List<User> getAll();//获取所有的记录
}

UserDaoImpl实现类

package com.legend.a_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 com.legend.bean.User;
/**
 * 使用JDBC模版实现增删改查
 * @author qichunlin
 *
 */
public class UserDaoImpl implements UserDao {

    //声明模版
    private JdbcTemplate jt;
    
    public void setJt(JdbcTemplate jt) {
        this.jt = jt;
    }

    //增
    @Override
    public void save(User u) { 
        String sql = "insert into t_user values(null,?)";
        jt.update(sql,u.getName());
        System.out.println("执行完毕");
    }

    //删
    @Override
    public void delete(Integer id) {
        // TODO Auto-generated method stub
        String sql = "delete from t_user where id=?";
        jt.update(sql,id);
        System.out.println("执行完毕");
    }

    //改
    @Override
    public void update(User u) {
        // TODO Auto-generated method stub
        String sql = "update t_user set name=? where id=?";
        jt.update(sql,u.getName(),u.getId());
        System.out.println("执行完毕");
    }

    //通过id查找用户
    @Override
    public User getById(Integer id) {
        // TODO Auto-generated method stub
        String sql = "select * from t_user where id=?";
        return jt.queryForObject(sql, new RowMapper<User>() {

            @Override
            public User mapRow(ResultSet rs, int arg1) throws SQLException {
                // 不需要判断是否有值
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setName(rs.getString("name"));
                
                System.out.println("执行完毕"); 
                
                return user;
            }},id);
            
    }

    //获取所有的行数
    @Override
    public int getTotalCount() {
        // TODO Auto-generated method stub
        String sql = "select count(*) from t_user ";
        
        //当返回的是值类型， 后面的Class对象就是
        Integer count = jt.queryForObject(sql, Integer.class);
        System.out.println("执行完毕");
        return count;
    }

    //获取所有的对象记录
    @Override
    public List<User> getAll() {
        String sql = "select * from t_user ";
        List<User> list = jt.query(sql, new RowMapper<User>() {

            @Override
            public User mapRow(ResultSet rs, int arg1) throws SQLException {
                // 不需要判断是否有值
                User user = new User();
                user.setId(rs.getInt("id"));
                user.setName(rs.getString("name"));
                return user;
            }});
        return list;
    }

}

applicationContext.xml主配置文件

<?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 ">

    <!-- 1.将连接池放入spring容器 -->
    <bean name="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="jdbcUrl" value="jdbc:mysql:///crm"></property>
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123456"></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="com.legend.a_jdbctemplate.UserDaoImpl">
        <property name="jt" ref="jdbcTemplate"></property>
    </bean>
</beans>

DemoTest测试类

package com.legend.a_jdbctemplate;

import java.util.List;

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.legend.bean.User;
import com.mchange.v2.c3p0.ComboPooledDataSource;
/**
 * SpringJDBC演示
 * @author qichunlin
 *
 */
//创建容器
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:applicationContext.xml")
public class DemoTest2 {
    
    //操作userDao对象
    @Resource(name="userDao")
    private UserDao ud;

    @Test
    public void fun2() throws Exception {
        User u = new User();
        u.setName("ATencent");
        ud.save(u);
    }

    @Test
    public void fun3() throws Exception {
        User u = new User();
        u.setId(10);
        u.setName("hhhh");
        ud.update(u);
    }   
    
    @Test
    public void fun4() throws Exception {
        List<User> all = ud.getAll();
        System.out.println(all.size());
    }   

    
    @Test
    public void fun5() throws Exception {
        ud.delete(1);
    }
    
    @Test
    public void fun6() throws Exception {
        System.out.println(ud.getTotalCount());
    }
    
    

    //最原始的方法
    @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:///crm");
        dataSource.setUser("root");
        dataSource.setPassword("123456");
        
        //1.创建JDBC模版对象
        JdbcTemplate jt = new JdbcTemplate();
        jt.setDataSource(dataSource);
        
        //2.书写sql，并执行
        String sql = "insert into t_user values(3,'legend')";
        jt.update(sql);
        System.out.println("执行完毕");
    }
    
    
}