public class MyException extends Exception {     private static final long serialVersionUID = 1L;     private Type type;     public MyException( Type type )     {         super();         this.type = type;     }     public MyException( Throwable t, Type type )     {         super( t );         this.type = type;     }     public String toString() {         return super.toString() + "<" + getErrorType().getErrorCode() + ">";     }     public Type getErrorType()     {         return type;     }     public enum Type     {         // 系统错误         SYSTEM_ERROR( "99999" ),         // 用户认证错误         USER_AUTH( "03003" );         private String errorCode;         Type( String errorCode )         {             this.errorCode = errorCode;         }         public String getErrorCode()         {             return this.errorCode;         }     } }