UnsupportedOperationException https://liferay.dev/c/message_boards/find_thread?p_l_id=119785294&threadId=110376156 2026-04-05T08:56:09Z 2026-04-05T08:56:09Z Sandeep Nair https://liferay.dev/c/message_boards/find_message?p_l_id=119785294&messageId=110377827 2018-06-29T13:08:26Z 2018-06-29T13:08:26Z

<p>Hi Manish,</p> <p> </p> <p>The log clearly shows that you are working with UnmodifiableList and you need to make a copy of it if you want to modify(which is the solution).</p> <p> <br /> java.lang.UnsupportedOperationException: Please make a copy of this read-only list before modifying it.<br />     at com.liferay.portal.kernel.util.UnmodifiableList$1.remove(UnmodifiableList.java:122)</p> <p> </p> <p>It's difficult to say how you have ended up using UnmodifiableList without seeing the previous part of the code where you have created the List in first placed. My gut feeling says you might have used ListUtil.sublist() method which is internally creating sublist using UnmodifiableList.</p> <p> </p> <p>Regards,</p> <p>Sandeep Nair</p>

Sandeep Nair 2018-06-29T13:08:26Z Ravi Shah https://liferay.dev/c/message_boards/find_message?p_l_id=119785294&messageId=110377213 2018-06-29T12:54:27Z 2018-06-29T12:54:27Z

<p>Hi, </p> <p> </p> <p>If you are trying to delete something from liferay generated entities, please do it with help of *LocalServiceUtil methods </p> <p>OR</p> <p>Simply loop through the list and assign it to a new list.</p>

Ravi Shah 2018-06-29T12:54:27Z manish kumar https://liferay.dev/c/message_boards/find_message?p_l_id=119785294&messageId=110376155 2018-06-29T11:53:57Z 2018-06-29T11:53:57Z

<p>Hi all</p> <p>I am facing this below problem while I am trying to modify the list ............</p> <p>the list is of model class  type . Actually I am trying to delete some element from the list .</p> <p>Please help us out.</p> <p>Error trace is below.</p> <p> <br /> java.lang.UnsupportedOperationException: Please make a copy of this read-only list before modifying it.<br />     at com.liferay.portal.kernel.util.UnmodifiableList$1.remove(UnmodifiableList.java:122)<br />     at com.addMe.action.DeviceDrag.serveResource(DeviceDrag.java:2981)<br />     at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:122)<br />     at com.liferay.portlet.ScriptDataPortletFilter.doFilter(ScriptDataPortletFilter.java:82)<br />     at com.liferay.portlet.FilterChainImpl.doFilter(FilterChainImpl.java:116)<br />     at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:71)<br />     at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:112)<br />     at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)<br />     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)<br />     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:119)<br />     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)<br />     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)<br />     at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)<br />     at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:487)<br />     at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)<br />     at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)<br />     at com.liferay.portlet.InvokerPortletImpl.invoke(InvokerPortletImpl.java:580)<br />     at com.liferay.portlet.InvokerPortletImpl.invokeResource(InvokerPortletImpl.java:675)<br />     at com.liferay.portlet.InvokerPortletImpl.serveResource(InvokerPortletImpl.java:441)<br />     at com.liferay.portlet.PortletContainerImpl._doServeResource(PortletContainerImpl.java:792)<br />     at com.liferay.portlet.PortletContainerImpl.serveResource(PortletContainerImpl.java:152)<br />     at com.liferay.portlet.SecurityPortletContainerWrapper.serveResource(SecurityPortletContainerWrapper.java:166)<br />     at com.liferay.portlet.RestrictPortletContainerWrapper.serveResource(RestrictPortletContainerWrapper.java:166)<br />     at com.liferay.portal.kernel.portlet.PortletContainerUtil.serveResource(PortletContainerUtil.java:164)<br />     at com.liferay.portal.action.LayoutAction.processLayout(LayoutAction.java:386)<br />     at com.liferay.portal.action.LayoutAction.doExecute(LayoutAction.java:200)<br />     at com.liferay.portal.action.LayoutAction.execute(LayoutAction.java:95)<br />     at org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:431)<br />     at org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:236)<br />     at com.liferay.portal.struts.PortalRequestProcessor.process(PortalRequestProcessor.java:179)<br />     at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)<br />     at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)<br />     at javax.servlet.http.HttpServlet.service(HttpServlet.java:647)<br />     at com.liferay.portal.servlet.MainServlet.callParentService(MainServlet.java:549)<br />     at com.liferay.portal.servlet.MainServlet.service(MainServlet.java:526)<br />     at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)<br />     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)<br />     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.secure.SecureFilter.processFilter(SecureFilter.java:293)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.jsoncontenttype.JSONContentTypeFilter.processFilter(JSONContentTypeFilter.java:42)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:119)<br />     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)<br />     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)<br />     at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)<br />     at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:487)<br />     at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)<br />     at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)<br />     at com.liferay.portal.servlet.FriendlyURLServlet.service(FriendlyURLServlet.java:156)<br />     at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)<br />     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)<br />     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:116)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.gzip.GZipFilter.processFilter(GZipFilter.java:123)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.secure.SecureFilter.processFilter(SecureFilter.java:293)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.i18n.I18nFilter.processFilter(I18nFilter.java:243)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.jsoncontenttype.JSONContentTypeFilter.processFilter(JSONContentTypeFilter.java:42)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.autologin.AutoLoginFilter.processFilter(AutoLoginFilter.java:267)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.sso.ntlm.NtlmPostFilter.processFilter(NtlmPostFilter.java:83)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.sharepoint.SharepointFilter.processFilter(SharepointFilter.java:88)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.processFilter(BaseFilter.java:169)<br />     at com.liferay.portal.servlet.filters.virtualhost.VirtualHostFilter.processFilter(VirtualHostFilter.java:226)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:185)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:96)<br />     at org.tuckey.web.filters.urlrewrite.UrlRewriteFilter.doFilter(UrlRewriteFilter.java:738)<br />     at com.liferay.portal.servlet.filters.urlrewrite.UrlRewriteFilter.processFilter(UrlRewriteFilter.java:57)<br />     at com.liferay.portal.kernel.servlet.BaseFilter.doFilter(BaseFilter.java:59)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDoFilter(InvokerFilterChain.java:204)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:109)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:165)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:96)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:165)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:96)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.processDirectCallFilter(InvokerFilterChain.java:185)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilterChain.doFilter(InvokerFilterChain.java:96)<br />     at com.liferay.portal.kernel.servlet.filters.invoker.InvokerFilter.doFilter(InvokerFilter.java:119)<br />     at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)<br />     at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)<br />     at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)<br />     at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)<br />     at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)<br />     at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)<br />     at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:99)<br />     at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)<br />     at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)<br />     at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)<br />     at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1023)<br />     at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:589)<br />     at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)<br />     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)<br />     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)<br />     at java.lang.Thread.run(Thread.java:745)<br />  </p>

manish kumar 2018-06-29T11:53:57Z