ArrayList参数在ServerRpc中的类型

Question

我创建了自定义组件，只使用IDE生成的组件。

RightClick on project > New > Vaadin Widget

并添加xxxWidgetset.gwt.xml并继承主项目widgetset.gwt.xml。我的组件结构如下。

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并使用java.util.ArrayList更改了某些ServerRpc方法的参数类型，并从某些事件中调用。

我在控制台上得到了下面的错误日志。

Aug 09, 2014 5:01:17 AM com.vaadin.server.DefaultErrorHandler doDefault
SEVERE: 
java.lang.ClassCastException: org.json.JSONArray cannot be cast to org.json.JSONObject
at com.vaadin.server.JsonCodec.decodeCustomType(JsonCodec.java:316)
at com.vaadin.server.JsonCodec.decodeInternalOrCustomType(JsonCodec.java:275)
at com.vaadin.server.communication.ServerRpcHandler.parseServerRpcInvocation(ServerRpcHandler.java:462)
at com.vaadin.server.communication.ServerRpcHandler.parseInvocation(ServerRpcHandler.java:395)
at com.vaadin.server.communication.ServerRpcHandler.parseInvocations(ServerRpcHandler.java:338)
at com.vaadin.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:206)
at com.vaadin.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:168)
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:93)
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41)
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1405)
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:237)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

为什么？我认为Vaadin组件的RPC方法不支持java.util.ArrayList.我说得对吗？

Answer 1

您试过使用List而不是ArrayList吗？根据这个错误票，http://dev.vaadin.com/ticket/11669 ArrayList与服务器到客户端RPC断开，但是List应该可以工作。