Java異步NIO servlet現在按預期工作

我試圖把一個簡單的servlet（從另一個源複製）工作。這是一個使用NIO通過ReadListener讀取發佈請求的異步servlet。這是代碼：Java異步NIO servlet現在按預期工作

@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"); 
}

}

當我發送POST請求到這個servlet，這段代碼的輸出是：

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

如此看來，一切都在執行同一個線程。直到3秒暫停結束，纔會讀取請求，然後打印最後3條消息。

任何線索爲什麼這不能正常工作？

謝謝。

來源

2016-03-01 JBalaguero

有一個3秒暫停...

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

註釋掉這一行。

來源

2016-03-01 14:44:41 Xvolks

沒有暫停，結果是一樣的。我的問題是：onDataAvailable和onAlldataRead不應該顯示主線程的另一個不同的線程？ – JBalaguero

我不這麼認爲，除非你在其他線程中運行它。 – Xvolks

Java異步NIO servlet現在按預期工作

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