error

java.sql.SQLException: null,  message from server: "Host 'c-68-54-103-171.hsd1.t
n.comcast.net' is not allowed to connect to this MySQL server"
        at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:946)
        at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1053)
        at com.mysql.jdbc.Connection.createNewIO(Connection.java:2743)
        at com.mysql.jdbc.Connection.<init>(Connection.java:1553)
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java
:266)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at java.sql.DriverManager.getConnection(Unknown Source)
        at server.<init>(server.java:32)
        at server.main(server.java:52)
Error: Unable to startup listener on 43594 - port already in use?
Exception in thread "main" java.lang.NullPointerException
        at ItemHandler.SQLloadItemList(ItemHandler.java:345)
        at ItemHandler.<init>(ItemHandler.java:46)
        at server.main(server.java:57)
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