Java异步NIO servlet现在按预期工作

我试图把一个简单的servlet（从另一个源复制）工作。这是一个使用NIO通过ReadListener读取发布请求的异步servlet。这是代码：Java异步NIO servlet现在按预期工作

@WebServlet(name = "AsyncProxyServlet2", urlPatterns = "/*" , asyncSupported = true) 
public class AsyncProxyServlet2 extends HttpServlet 
{ 
private static final long serialVersionUID = 8458401860448619054L; 

@Override 
public void doPost(HttpServletRequest request, HttpServletResponse response) throws IOException 
{ 
    final AsyncContext acontext = request.startAsync(); 
    final ServletInputStream input = request.getInputStream(); 
    System.out.println("request.isAsyncStarted() = " + request.isAsyncStarted() + ", request.isAsyncSupported = " + request.isAsyncSupported() + ", main = " + Thread.currentThread().getName()); 

    input.setReadListener(new ReadListener() 
    { 
    byte tmp[] = new byte[4*1024]; 
    ByteArrayOutputStream buffer  = new ByteArrayOutputStream(this.tmp.length); 

    @Override 
    public void onDataAvailable() 
    { 
    try 
    { 
    System.out.println("onDataAvailable = " + Thread.currentThread().getName());  
    int numBytesRead = -1; 

    while (input.isReady() && !input.isFinished()) 
    { 
     if ((numBytesRead = input.read(this.tmp)) > 0) this.buffer.write(this.tmp, 0, numBytesRead); 
    } 
    } 
    catch (IOException ex) { ex.printStackTrace(); } 
    } 

    @Override 
    public void onAllDataRead() 
    { 
    try 
    { 
    System.out.println("onAllDataRead = " + Thread.currentThread().getName() + ", buffer size = " + this.buffer.size());  

    acontext.getResponse().setContentType("text/xml; charset=utf-8"); 
    acontext.getResponse().setContentLength(this.buffer.size()); 
    acontext.getResponse().getOutputStream().write(this.buffer.toByteArray()); 
    } 
    catch (Exception ex) { ex.printStackTrace(); } 

    acontext.complete(); 
    } 

    @Override 
    public void onError(Throwable t) { t.printStackTrace(); } 
    }); 

    System.out.println("final 1"); 
    try { Thread.sleep(3000); } catch (Exception e) {} 
    System.out.println("final 2"); 
}

}

当我发送POST请求到这个servlet，这段代码的输出是：

request.isAsyncStarted() = true, request.isAsyncSupported = true, main = http-nio-80-exec-1 
final 1 
<-- Here a 3 second pause 
final 2 
onDataAvailable = http-nio-80-exec-1 
onAllDataRead = http-nio-80-exec-1, buffer size = 910

如此看来，一切都在执行同一个线程。直到3秒暂停结束，才会读取请求，然后打印最后3条消息。

任何线索为什么这不能正常工作？

谢谢。

来源

2016-03-01 JBalaguero

有一个3秒暂停...

try { Thread.sleep(3000); } catch (Exception e) {}

注释掉这一行。

来源

2016-03-01 14:44:41 Xvolks

没有暂停，结果是一样的。我的问题是：onDataAvailable和onAlldataRead不应该显示主线程的另一个不同的线程？ – JBalaguero

我不这么认为，除非你在其他线程中运行它。 – Xvolks

Java异步NIO servlet现在按预期工作

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