JDBC连接数据库

Posted 2020-11-24 緑青色の

JDBC连接数据库

??连接mysql必导包【mysql-connector-java-5.1.47.jar】

??这里提供了连接mysql相关jar包的所有版本：https://mvnrepository.com/artifact/mysql/mysql-connector-java

相关配置文件：（jdbc.properties）

# 加载驱动
jdbc.driver=com.mysql.jdbc.Driver
# 注册驱动
jdbc.url=jdbc:mysql://localhost:3306/stmng?useUnicode=true&characterEncoding=utf8&useSSL=true
# 连接数据库的用户名
jdbc.user=root
# 连接数据库的密码
jdbc.password=root

JDBC连接工具类

package com.lyang.util;

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

/**
 * jdbc连接工具类
 */
public class JDBCUtil {
    
      private static final String DRIVER;
      private static final String URL; 
      private static final String USER;
      private static final String PASSWORD;
     
    static {
        InputStream ips = null;
        Properties prop = null;
        try {
            // 加载配置文件
            ips = JDBCUtil.class.getClassLoader().getResourceAsStream("jdbc.properties");
            prop = new Properties();
            prop.load(ips);
        } catch (IOException e) {
            e.printStackTrace();
        }
        DRIVER = prop.getProperty("jdbc.driver");
        URL = prop.getProperty("jdbc.url");
        USER = prop.getProperty("jdbc.user");
        PASSWORD = prop.getProperty("jdbc.password");
        // 加载驱动
        try {
            Class.forName(DRIVER);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }
    
    /**
     * 获取连接
     * @return
     */
    public static Connection getConn() {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(URL, USER, PASSWORD);
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return conn;
    }
    
    /**
     * 释放资源
     * @param conn
     * @param prep
     */
    public static void close(Connection conn, PreparedStatement prep) {
        try {
            if (null != conn) {
                conn.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            if (null != prep) {
                prep.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public static void close(Connection conn,PreparedStatement prep,ResultSet rs) {
        try {
            if (null!=rs) {
                rs.close();
            }
            close(conn, prep);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args) {
        System.out.println(getConn());
    }
    
}