java连接mysql 的问题，请过来看一下？

com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.net.SocketException
MESSAGE: java.net.ConnectException: Connection timed out: connectSTACKTRACE:java.net.SocketException: java.net.ConnectException: Connection timed out: connect
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:151)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:280)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1699)
at com.mysql.jdbc.Connection.<init>(Connection.java:405)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:268)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at com.by.cngp.YwThread.getConnection(YwThread.java:47)
at com.by.cngp.YwThread.run(YwThread.java:69)
** END NESTED EXCEPTION **
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1764)
at com.mysql.jdbc.Connection.<init>(Connection.java:405)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:268)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at com.by.cngp.YwThread.getConnection(YwThread.java:47)
at com.by.cngp.YwThread.run(YwThread.java:69)
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: ** BEGIN NESTED EXCEPTION ** java.io.EOFExceptionSTACKTRACE:java.io.EOFException
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1845)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2292)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2788)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:753)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1208)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1702)
at com.mysql.jdbc.Connection.<init>(Connection.java:405)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:268)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at com.by.cngp.YwThread.getConnection(YwThread.java:47)
at com.by.cngp.YwThread.run(YwThread.java:69)
** END NESTED EXCEPTION **
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2504)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2788)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:753)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1208)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:1702)
at com.mysql.jdbc.Connection.<init>(Connection.java:405)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:268)
at java.sql.DriverManager.getConnection(DriverManager.java:512)
at java.sql.DriverManager.getConnection(DriverManager.java:171)
at com.by.cngp.YwThread.getConnection(YwThread.java:47)
at com.by.cngp.YwThread.run(YwThread.java:69)
连接mysql 后不久就会出现上面的错误，我是这样写得
                         while (!interrupted()) {
                         try{
                         do{
sqlConn=getConnection();
}while(sqlConn==null);
                          }catch(Exceptin e){}
                           finally{
                               try{if(sqlConn!=null) sqlConn.close();}catch(Exception e){}
                            }
                          }
请高手指点下！