Help:apache tomcat服务器的错误：严重: Servlet.service() for servlet ygkh threw exception java.lang.OutOfMemoryError: PermGen space

在本机调试程序时，有时会出现这个错误，重新启动服务就好了，但不知为什么会出现这样的问题，不知道项目正式上线使用的时候会不会出现这样的问题。
严重: Servlet.service() for servlet ygkh threw exception
java.lang.OutOfMemoryError: PermGen space
 at org.apache.tapestry.error.RequestExceptionReporterImpl.reportRequestException(RequestExceptionReporterImpl.java:46)
 at $RequestExceptionReporter_11e9cad1906.reportRequestException($RequestExceptionReporter_11e9cad1906.java)
 at $RequestExceptionReporter_11e9cad1905.reportRequestException($RequestExceptionReporter_11e9cad1905.java)
 at org.apache.tapestry.error.ExceptionPresenterImpl.presentException(ExceptionPresenterImpl.java:53)
 at $ExceptionPresenter_11e9cad18e8.presentException($ExceptionPresenter_11e9cad18e8.java)
 at $ExceptionPresenter_11e9cad18e7.presentException($ExceptionPresenter_11e9cad18e7.java)
 at org.apache.tapestry.engine.AbstractEngine.activateExceptionPage(AbstractEngine.java:121)
 at org.apache.tapestry.engine.AbstractEngine.service(AbstractEngine.java:280)
 at org.apache.tapestry.services.impl.InvokeEngineTerminator.service(InvokeEngineTerminator.java:60)
 at $WebRequestServicer_11e9cad1945.service($WebRequestServicer_11e9cad1945.java)
 at org.apache.tapestry.services.impl.DisableCachingFilter.service(DisableCachingFilter.java:48)
 at $WebRequestServicerFilter_11e9cad1947.service($WebRequestServicerFilter_11e9cad1947.java)
 at $WebRequestServicer_11e9cad1949.service($WebRequestServicer_11e9cad1949.java)
 at $WebRequestServicer_11e9cad1941.service($WebRequestServicer_11e9cad1941.java)
 at org.apache.tapestry.services.impl.WebRequestServicerPipelineBridge.service(WebRequestServicerPipelineBridge.java:56)
 at $ServletRequestServicer_11e9cad1927.service($ServletRequestServicer_11e9cad1927.java)
 at org.apache.tapestry.request.DecodedRequestInjector.service(DecodedRequestInjector.java:55)
 at $ServletRequestServicerFilter_11e9cad1923.service($ServletRequestServicerFilter_11e9cad1923.java)
 at $ServletRequestServicer_11e9cad1929.service($ServletRequestServicer_11e9cad1929.java)
 at org.apache.tapestry.multipart.MultipartDecoderFilter.service(MultipartDecoderFilter.java:52)
 at $ServletRequestServicerFilter_11e9cad1921.service($ServletRequestServicerFilter_11e9cad1921.java)
 at $ServletRequestServicer_11e9cad1929.service($ServletRequestServicer_11e9cad1929.java)
 at org.apache.tapestry.services.impl.SetupRequestEncoding.service(SetupRequestEncoding.java:53)
 at $ServletRequestServicerFilter_11e9cad1925.service($ServletRequestServicerFilter_11e9cad1925.java)
 at $ServletRequestServicer_11e9cad1929.service($ServletRequestServicer_11e9cad1929.java)
 at $ServletRequestServicer_11e9cad191b.service($ServletRequestServicer_11e9cad191b.java)
 at org.apache.tapestry.ApplicationServlet.doService(ApplicationServlet.java:123)
 at org.apache.tapestry.ApplicationServlet.doPost(ApplicationServlet.java:168)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
 at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
 at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
 at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)