今天想写个jdbc连接mysql的测试，写好了以后连不上msql,报如下错误：
com.mysql.jdbc.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2120)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:723)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:298)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
at java.sql.DriverManager.getConnection(DriverManager.java:525)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at welfare.DBUtil.getMySQLConnection(DBUtil.java:64)
at welfare.Test.main(Test.java:17)
Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure
Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1070)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:335)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2043)
... 7 more
Caused by: java.net.ConnectException: Connection refused: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:520)
at java.net.Socket.connect(Socket.java:470)
at java.net.Socket.<init>(Socket.java:367)
at java.net.Socket.<init>(Socket.java:209)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:284)
... 8 more
后来仔细一检查才发现原来是url连接的端口写错了。