029 c3p0的小测试

　　今天被问到这个问题，就实验了一下，后续会继续补充一些配置项的意思。

一：操作步骤

1.大纲

　　

2.新建sql

-- ----------------------------
-- Table structure for user
-- ----------------------------
DROP TABLE IF EXISTS `user`;
CREATE TABLE `user` (
  `id` int(16) NOT NULL,
  `name` varchar(255) DEFAULT NULL,
  `password` varchar(255) DEFAULT NULL,
  `email` varchar(255) DEFAULT NULL,
  `phone` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of user
-- ----------------------------
INSERT INTO `user` VALUES ('1', 'aa', '12', '12@qq.com', '1234567890');

3.domain

package com.jun.it;

public class User {
    private int id;
    private String name;
    private String password;
    private String email;
    private String phone;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getPhone() {
        return phone;
    }
    public void setPhone(String phone) {
        this.phone = phone;
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", name=" + name + ", password=" + password + ", email=" + email + ", phone=" + phone
                + "]";
    }
    
}

4.c3p0-config.xml

<c3p0-config>
    
    <!-- c3p0默认配置，下面还可以配置多个数据库 -->
    <default-config>
        <property name="jdbcUrl">jdbc:mysql://127.0.0.1:3308/test?serverTimezone=UTC&amp;useUnicode=true&amp;characterEncoding=utf8&amp;useSSL=true</property>
        <property name="driverClass">com.mysql.cj.jdbc.Driver</property>
        <property name="user">root</property>
        <property name="password">123456</property>
        <property name="minPoolSize">5</property>
        <property name="maxPoolSize">2</property>
        <property name="maxIdleTime">10</property>
    </default-config>

</c3p0-config>

5.测试类

package com.jun.it;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

import com.mchange.v2.c3p0.ComboPooledDataSource;

public class C3p0Test {
     //使用编码方式实现c3p0数据库连接池
    @Test
    public void TestXml() throws Exception{
        //第一步：创建连接池核心工具类
        ComboPooledDataSource dataSource=new ComboPooledDataSource();
        
        //第三步：从连接池对象中获取数据库连接
        Connection con=dataSource.getConnection();
        String sql="select * from user ";
        PreparedStatement ps=con.prepareStatement(sql);
        ResultSet rs=ps.executeQuery();
        
        List<User> list=new ArrayList<User>();
        while(rs.next()){
            User user=new User();
            user.setId(rs.getInt("id"));
            user.setName(rs.getString("name"));
            user.setPassword(rs.getString("password"));
            user.setEmail(rs.getString("email"));
            user.setPhone(rs.getString("phone"));
            list.add(user);
        }
        
        System.out.println("~~~"+list);
    }
}

6.效果