JdbcUtils工具类

JdbcUtils1.0版本

 

1.首先编写dbconfig.properties配置文件

driverClassName=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/student
username=root
password=123

2.编写JdbcUtil1.java工具类

package cn.cmlx.jdbcutils;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

/**
 * version1.0
 * @author 赤名莉香
 *
 */
public class JdbcUtil1 {
    private static Properties props = null;
    //只在JdbcUtil1类被加载时执行一次
    static {
        //给props进行初始化，即加载dbconfig.properties文件到props对象中
        try {
            InputStream in = JdbcUtil1.class.getClassLoader().getResourceAsStream("dbconfig.properties");
            props = new Properties();
            props.load(in);
        }catch (IOException e) {
            throw new RuntimeException(e);
        }
        
        //加载驱动类
        try {
            Class.forName(props.getProperty("driverClassName"));
        }catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        }
    }
    public static Connection getConnection() throws SQLException{
        //得到Connection
        return DriverManager.getConnection(props.getProperty("url"), props.getProperty("username"), props.getProperty("password"));
    }
}

3.应用

package cn.cmlx.test;

import java.sql.Connection;
import java.sql.SQLException;

import org.junit.Test;


import cn.cmlx.jdbcutils.JdbcUtil1;

public class Test2 {
@Test
public void func1() throws SQLException {
    Connection con = JdbcUtil1.getConnection();
    System.out.println(con);
    Connection con1 = JdbcUtil1.getConnection();
    System.out.println(con1);
　　}
}