mysql-Eclipse用JDBC连接不上MYSQL

使用JDBC的方法连接不上MySQL，我的网络是校园网，登陆后IP会变化，不知道这个对连接有没有什么影响，用的是mysql 5.6 以前用JDBC连接上过的，但是现在就不行了，不清楚原因，也在网上找过，但是找不到解决的办法，连接的JAR包是mysql-connector-java-5.1.26-bin.jar，提示错误Communication link failure, message from server: "Can't get hostname for your address"
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.Util.getInstance(Util.java:383)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1023)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:997)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:983)
at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1111)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2494)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2527)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2309)
at com.mysql.jdbc.ConnectionImpl.(ConnectionImpl.java:834)
at com.mysql.jdbc.JDBC4Connection.(JDBC4Connection.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:408)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:419)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:344)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)请知道的大神解答一下小弟