jdbc连接mysql数据库

maven包依赖

   <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.21</version>
   </dependency>

连接查询

初始化驱动

  static {
       try {
            Class.forName(driverclass);
       } catch (ClassNotFoundException e) {
            e.printStackTrace();
      }
 }

• jdbc4.0后, 驱动加载可省略， DriverManager初始化会隐式加载

参数

private static String user = "root";
	
private static String pwd = "123456";
	
private static String driverclass= "com.mysql.cj.jdbc.Driver";

private static String connectUrl = "jdbc:mysql://172.19.82.122:3306/xx

获取连接

public static Connection  getConnection() {
	try {
		return DriverManager.getConnection(connectUrl, user, pwd);
	} catch (SQLException e) {
		e.printStackTrace();
	}
	return null;
}

查询

public static void query(Connection conn) {
	Statement createStatement  = null;
	try {
		createStatement = conn.createStatement();
		ResultSet rs = createStatement.executeQuery(" select * from tb_user");
		
	} catch (SQLException e) {
		e.printStackTrace();
	}finally {
		try {
			createStatement.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
}

结果处理

while(rs.next()) {
	System.out.println(rs.getString("user_name"));
}