Java连接MySQL数据库（jdbc连接数据库）

一、实现代码

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
 
public class DBUtil {
 
	private static final String DRIVER = "com.mysql.jdbc.Driver";
    private static final String URL = "jdbc:mysql://localhost:3306/databasename?";
    private static final String USER = "root";
    private static final String PASSWORD = "123456";
    // 静态加载驱动
    static {
        try {
			Class.forName(DRIVER);
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
    }
    // 把连接对象赋给类属性，以避免重复连接
    public static Connection conn = getConnection();
    
    // 连接jdbc
    private static Connection getConnection() {
    	Connection conn = null;
    	try {
			conn = DriverManager.getConnection(URL, USER, PASSWORD);
			System.out.println("MySQL数据库连接成功！");
		} catch (SQLException e) {
			e.printStackTrace();
		}
    	return conn;
    }
    
    // 关闭连接对象
    public static boolean closeAll(ResultSet rs, PreparedStatement ps, Statement st, Connection conn) {
    	boolean flag = false;
    	try {
			if(rs != null) {
				rs.close();
			}if(ps != null) {
				ps.close();
			}if(st != null) {
				st.close();
			}if(conn != null) {
				conn.close();
			}flag = true;
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			// 即使抛出异常，GC也会对null对象快速回收
			rs = null; 
			ps = null; 
			st = null; 
			conn = null; 
		}
    	return flag;
    }
    
    public static void main(String[] args) {
    	
	}
}

二、前置条件

1、MySQL连接jar包

  	<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
	<dependency>
	    <groupId>mysql</groupId>
	    <artifactId>mysql-connector-java</artifactId>
	    <version>5.1.47</version>
	</dependency>

2、MySQL数据库配置

（1）账户密码 （2）数据库名

三、运行结果