28800 seconds,也就是8小时,如果在wait_timeout秒期间内,数据库连接(java.sql.Connection)一直处于等待状态,mysql5就将该连接关闭。这时,你的Java应用的连接池仍然合法地持有该连接的引用。当用该连接来进行数据库操作时,就碰到上述错误。 三、解决方式 1.mysql5以前的版本可以直接在jdbc
publicclassJdbcDemo{publicstaticvoidmain(String[] args)throwsException {//1、导入驱动jar包//2、注册驱动Class.forName("com.mysql.cj.jdbc.Driver");//3、获取数据库的连接对象Connectioncon=DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root","123456");//4、定义sql语句Stringsql="se...
3importjava.sql.Connection;4importjava.sql.DriverManager;5importjava.sql.ResultSet;6importjava.sql.SQLException;7importjava.sql.Statement;89publicclassDBConnettion {1011//不同版本的数据库驱动,名字会不相同同。12//数据库驱动 mysql-connector-java 6.0以上的版本, 驱动名是:"com.mysql.cj.jdbc.Driver"1...
Connection URL is explained here: http://dev.mysql.com/doc/connector-j/en/connector-j-reference-configuration-properties.html. You can find plenty of examples in several other plages. Basically what you need to start is a URL like this: - "jdbc:mysql://[host][:port]/[database]" ...
Connection con; //驱动程序名 String driver = "com.mysql.jdbc.Driver"; //URL指向要访问的数据库名mydata String url = "jdbc:mysql://localhost:3306/mysql"; //MySQL配置时的用户名 String user = "root"; //MySQL配置时的密码 String password = "***"; /...
packagesqldstudent;importjava.sql.Connection;importjava.sql.DriverManager;importjava.sql.ResultSet;importjava.sql.SQLException;importjava.sql.Statement;publicclassmain{publicstaticvoidmain(String[]args){//声明Connection对象Connection con;//驱动程序名String driver="com.mysql.jdbc.Driver";//URL指向要访问的...
publicclassMySqlConnectionExample{publicstaticvoidmain(String[]args){Stringurl="jdbc:mysql://localhost:3306/mydatabase?user=root&password=123456";try{Connectionconn=DriverManager.getConnection(url);System.out.println("Connected to MySql database successfully!");conn.close();}catch(SQLExceptione){e....
public void demo01() throws Exception { // 1注册驱动 Class.forName("com.mysql.jdbc.Driver"); // 2获取连接 Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydb", "root", "root"); // 3获得预处理对象 String sql = "insert into sort(sname) values(?)"; Prepare...
2 导入mysql的驱动包。方式1：直接将驱动jar包粘贴到lib文件夹中；然后在jar包上右键--add to build path 3 方式2： 通过配置变量引入驱动jar包，在项目名称上右键--Build Path--Config Build Path。4 点击：添加外部jar。（Add External jars）,选择驱动包, 点击OK 5 编写测试类:Connection conn = null; ...
I have simple java program to connect to mysql, I am getting the following error. Exception: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.net.SocketException MESSAGE: java.net.ConnectException: Connection refused: connect STACKTRACE: java.net.So...