Question

我正在使用Eclipse IDE来处理servlet。我创建了一个maven项目来处理异步servlet 3.0并添加了适当的依赖项。代码request.isAsyncSupported()返回true。现在，当我调用servlet时，它会出现此错误

WARN：oejs.ServletHandler：/ testplugin / JsonServlet java.lang.IllegalStateException：DISPATCHED，initial 在org.eclipse.jetty.server.Request.getAsyncContext（Request.java:325）在com.ajitpals.search.grid.fs.JsonServlet.doGet（JsonServlet.java:42）在javax.servlet.http.HttpServlet.service（HttpServlet.java:734）在javax.servlet.http.HttpServlet.service（HttpServlet.java:847）在org.eclipse.jetty.servlet.ServletHolder.handle（ServletHolder.java:594）在org.eclipse.jetty.servlet.ServletHandler.doHandle（ServletHandler.java:486）在org.eclipse.jetty.server.handler.ScopedHandler.handle（ScopedHandler.java:119）在org.eclipse.jetty.security.SecurityHandler.handle（SecurityHandler.java:524）在org.eclipse.jetty.server.session.SessionHandler.doHandle（SessionHandler.java:233）在org.eclipse.jetty.server.handler.ContextHandler.doHandle（ContextHandler.java:1065）在org.eclipse.jetty.servlet.ServletHandler.doScope（ServletHandler.java:413）在org.eclipse.jetty.server.session.SessionHandler.doScope（SessionHandler.java:192）在org.eclipse.jetty.server.handler.ContextHandler.doScope（ContextHandler.java:999）在org.eclipse.jetty.server.handler.ScopedHandler.handle（ScopedHandler.java:117）在org.eclipse.jetty.server.handler.HandlerWrapper.handle（HandlerWrapper.java:111）在org.eclipse.jetty.server.Server.handle（Server.java:351） at org.eclipse.jetty.server.AbstractHttpConnection.handleRequest（AbstractHttpConnection.java:454） at org.eclipse.jetty.server.AbstractHttpConnection.headerComplete（AbstractHttpConnection.java:890） at org.eclipse.jetty.server.AbstractHttpConnection $ RequestHandler.headerComplete（AbstractHttpConnection.java:944）在org.eclipse.jetty.http.HttpParser.parseNext（HttpParser.java:634）在org.eclipse.jetty.http.HttpParser.parseAvailable（HttpParser.java:230） at org.eclipse.jetty.server.AsyncHttpConnection.handle（AsyncHttpConnection.java:77）在org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle（SelectChannelEndPoint.java:609）在org.eclipse.jetty.io.nio.SelectChannelEndPoint $ 1.run（SelectChannelEndPoint.java:45）在org.eclipse.jetty.util.thread.QueuedThreadPool.runJob（QueuedThreadPool.java:599）在org.eclipse.jetty.util.thread.QueuedThreadPool $ 3.run（QueuedThreadPool.java:534）在java.lang.Thread.run（未知来源）。

我在maven项目中添加了以下依赖项。

 <dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1-b08</version>
</dependency>

<dependency>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-server</artifactId>
    <version>9.0.2.v20130417</version>
</dependency>

，servlet代码是

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    if(request.isAsyncSupported()){

    final AsyncContext asynCtx = request.getAsyncContext();

    //Set the timeout
    asynCtx.setTimeout(35000);

    //Add the listeners.
    asynCtx.addListener(new AsyncListener() {

        public void onTimeout(AsyncEvent arg0) throws IOException {
            System.out.println("timeout");              
        }

        public void onStartAsync(AsyncEvent arg0) throws IOException {
            System.out.println("on start");             
        }

        public void onError(AsyncEvent arg0) throws IOException {
            System.err.println("on error");             
        }

        public void onComplete(AsyncEvent arg0) throws IOException {
            System.out.println("On complete");              
        }
    });

    //start the new thread.
    asynCtx.start(new Runnable() {

        public void run() {
            try{
                asynCtx.getResponse().getWriter().write(MessageFormat.format("<h1>Process task id : [{0}] and Name [{1}]</h1>", 
                        Thread.currentThread().getId()));
            }catch(Exception ex){
                System.err.println("async error " + ex.getMessage());
            }
        }
    });
    }
}

是否有人遇到类似问题，我们如何解决它们。

修改

有时servlet也会出现以下错误

PWC6345: There is an error in invoking javac. A full JDK (not just JRE) is required Caused by:org.apache.jasper.JasperException:PWC6345: There is an error in invoking javac. A full JDK (not just JRE) is required

由于

Answer 1

这是代码错误，如果我们在getAsyncRequest()之前尝试获取request.startAsync()将产生错误。

使用Eclipse＆amp; amp;调用异步java servlet时出错行家

1 个答案: