Question

我正在使用RESTlet ClientResource从服务器资源调用google places端点。具体来说，REST请求调用RESTlet ServerResource，它调用ClientResource并返回Google Places结果。它在Tomcat中作为Web应用程序运行。

这可以正常工作大约一个小时，然后每个请求都会挂起。停止tomcat后，我看到所有请求都在日志中处理完毕。这非常不稳定，因为Tomcat需要每小时重启一次。

我已经找了一段时间的答案，并发现问题可能是连接未被释放。建议是在表示上使用耗尽并停止在客户端资源上。

我正在使用restlets 2.1.1的最新稳定版本。

以下是我执行上述过程的方法：

 ClientResource storeRoot = new ClientResource(placeEndPoint);
 Client c = (Client)storeRoot.getNext();

 String jsonString = storeRoot.get().getText();
    try {
    c.stop();
} catch (Exception e) {
    e.printStackTrace();
}

storeRoot.release();

在服务器资源返回表示的部分中，我称之为废气：

            JSONArray ja = new JSONArray(placesList);
    JsonRepresentation jr = new JsonRepresentation(ja);
    jr.setCharacterSet(CharacterSet.UTF_8);
    try {
        jr.exhaust();
        jr.release();
    } catch (IOException e) {
        e.printStackTrace();
    } finally{

    }

    return jr;

有谁知道如何阻止客户端资源挂起？

Answer 1

问题是ClientResource在关闭连接时遇到问题。对我有用的是使用apache httpclient。

我使用以下方法在RESTlet资源中执行http get：

 public String httpGet(String url) throws IllegalStateException, IOException {

    HttpClient httpclient = new DefaultHttpClient();

     // Prepare a request object
     HttpGet httpget = new HttpGet(url);

     // Execute the request
     HttpResponse response = httpclient.execute(httpget);

     // Examine the response status
     System.out.println(response.getStatusLine());

     // Get hold of the response entity
     HttpEntity entity = response.getEntity();

     // If the response does not enclose an entity, there is no need
     // to worry about connection release
     if (entity != null) {
         InputStream instream = entity.getContent();
         try {

             BufferedReader reader = new BufferedReader(
                     new InputStreamReader(instream));
             // do something useful with the response
             //System.out.println(reader.readLine());

             StringBuilder builder = new StringBuilder();
             String aux = "";

             while ((aux = reader.readLine()) != null) {
                 builder.append(aux);
             }

             String text = builder.toString();

             return text;

         } catch (IOException ex) {

             // In case of an IOException the connection will be released
             // back to the connection manager automatically
             throw ex;

         } catch (RuntimeException ex) {

             // In case of an unexpected exception you may want to abort
             // the HTTP request in order to shut down the underlying
             // connection and release it back to the connection manager.
             httpget.abort();
             throw ex;

         } finally {

             // Closing the input stream will trigger connection release
             instream.close();
             httpclient.getConnectionManager().shutdown();
         }

         // When HttpClient instance is no longer needed,
         // shut down the connection manager to ensure
         // immediate deallocation of all system resources

     }

     return null;
  }

Answer 2

ClientConnectionHelper负责关闭ClientResource的连接。每当您完成请求时，您应该调用storeRoot.release（）来告诉ClientConnectionHelper停止连接。

RESTlet ClientResource在多次调用远程主机后挂起

2 个答案: