mysql端口修改jdbc连接_如何检查默认端口号为mysql连接？连接不工作！ jdbc连接...

I am trying to connect with database using jdbc in java file. It is not connecting at all and giving me the error constantly "Something went wrong"; I guess it is because of the port number because all other data such as username, password and other code seems correct.

I want to check the default port number so that I can try it properly. I did try using all three of these 8080, 80 and 3306 but it shows me error.

Here port 8080 is used for HTTP server, 3306 is supposed to be default from the research and 80 randomly.

try {

Class.forName("com.mysql.jdbc.Driver");

System.out.println("Driver found");

} catch (ClassNotFoundException e) {

System.out.println("Driver not found");

}

String url="jdbc:mysql://localhost:8080 or 80 or 3306 or without port number/test";

String user="user";

String password="";

Connection con=null;

try {

con=DriverManager.getConnection(url, user, password);

System.out.println("Success");

} catch (SQLException e){

e.printStackTrace();

}

}

The error is giving below when used String url="jdbc:mysql://localhost:3306/test";

Driver found

com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)

at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1036)

at com.mysql.jdbc.MysqlIO.(MysqlIO.java:338)

at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2232)

at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2265)

at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2064)

at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:790)

at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:44)

at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)

at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)

at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)

at java.lang.reflect.Constructor.newInstance(Constructor.java:513)

at com.mysql.jdbc.Util.handleNewInstance(Util.java:377)

at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:395)

at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)

at java.sql.DriverManager.getConnection(DriverManager.java:582)

at java.sql.DriverManager.getConnection(DriverManager.java:185)

at com.town.connect.Dbconnection.main(Dbconnection.java:26)

Caused by: java.net.ConnectException: Connection refused

at java.net.PlainSocketImpl.socketConnect(Native Method)

at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:382)

at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:241)

at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:228)

at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:431)

at java.net.Socket.connect(Socket.java:527)

at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:213)

at com.mysql.jdbc.MysqlIO.(MysqlIO.java:297)

... 15 more

解决方案

You can access those settings via

mysql> show variables;