最近在做文件上传的功能时，经常报如下异常，OutOfMemorError，想问一下，除了增加jetty的内存的方法，有没有其他可能的方法，会不会是某个流文件没有关?
Exception in thread "JFinal-Scanner" java.lang.OutOfMemoryError: PermGen space
at org.apache.log4j.Category.forcedLog(Category.java:391)
at org.apache.log4j.Category.log(Category.java:856)
at org.slf4j.impl.Log4jLoggerAdapter.log(Log4jLoggerAdapter.java:602)
at org.eclipse.jetty.util.log.JettyAwareLogger.log(JettyAwareLogger.java:607)
at org.eclipse.jetty.util.log.JettyAwareLogger.warn(JettyAwareLogger.java:431)
at org.eclipse.jetty.util.log.Slf4jLog.warn(Slf4jLog.java:69)
at org.eclipse.jetty.util.component.AbstractLifeCycle.setFailed(AbstractLifeCycle.java:204)
at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:74)
at com.jfinal.server.JettyServer$1.onChange(JettyServer.java:103)
at com.jfinal.server.Scanner.compare(Scanner.java:87)
at com.jfinal.server.Scanner.working(Scanner.java:56)
at com.jfinal.server.Scanner.access$0(Scanner.java:54)
at com.jfinal.server.Scanner$1.run(Scanner.java:93)
at java.util.TimerThread.mainLoop(Timer.java:555)
at java.util.TimerThread.run(Timer.java:505)
