apache http客户端org.apache.http.NoHttpResponseException：目标服务器无法响应

Question

我正在使用apache http客户端来测试我的WS。我已经在球衣上写了一个WS。该WS的URL是

http://localhost:8080/mobilestore/rest/sysgestockmobilews/getinventory?xml=dataString

用URL调用这个WS我写了一个方法如下

public static void getInventory(String input)
        throws ClientProtocolException, IOException {

    System.out.println(input);
    String url = URL + "getinventory";
    HttpClient client = new DefaultHttpClient();

    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
    nameValuePairs.add(new BasicNameValuePair("xml", input));
    String paramString = URLEncodedUtils.format(nameValuePairs, "utf-8");
    url += "?" + paramString;
    System.out.println(url);
    HttpGet request = new HttpGet(url);
    HttpResponse response = client.execute(request);
    BufferedReader rd = new BufferedReader(new InputStreamReader(response
            .getEntity().getContent()));

    String line = "";
    while ((line = rd.readLine()) != null) {
        System.out.println(line);
    }

}

现在，当我运行程序并将URL传递给此函数时，我在行中得到了异常

HttpResponse response = client.execute(request);

异常如下

Aug 14, 2013 9:31:50 PM org.apache.http.impl.client.DefaultRequestDirector tryExecute
INFO: I/O exception (org.apache.http.NoHttpResponseException) caught when processing         request: The target server failed to respond
Aug 14, 2013 9:31:50 PM org.apache.http.impl.client.DefaultRequestDirector tryExecute
INFO: Retrying request
Aug 14, 2013 9:31:50 PM org.apache.http.impl.client.DefaultRequestDirector tryExecute
INFO: I/O exception (org.apache.http.NoHttpResponseException) caught when processing   request: The target server failed to respond
Aug 14, 2013 9:31:50 PM org.apache.http.impl.client.DefaultRequestDirector tryExecute
INFO: Retrying request
Aug 14, 2013 9:31:50 PM org.apache.http.impl.client.DefaultRequestDirector tryExecute
INFO: I/O exception (org.apache.http.NoHttpResponseException) caught when processing      request: The target server failed to respond
Aug 14, 2013 9:31:50 PM org.apache.http.impl.client.DefaultRequestDirector tryExecute
INFO: Retrying request
Exception in thread "main" org.apache.http.NoHttpResponseException: The target server failed to respond
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:95)
at org.apache.http.impl.conn.DefaultHttpResponseParser.parseHead(DefaultHttpResponseParser.java:62)
at org.apache.http.impl.io.AbstractMessageParser.parse(AbstractMessageParser.java:254)
at org.apache.http.impl.AbstractHttpClientConnection.receiveResponseHeader(AbstractHttpClientConnection.java:289)
at org.apache.http.impl.conn.DefaultClientConnection.receiveResponseHeader(DefaultClientConnection.java:252)
at org.apache.http.impl.conn.ManagedClientConnectionImpl.receiveResponseHeader(ManagedClientConnectionImpl.java:191)
at org.apache.http.protocol.HttpRequestExecutor.doReceiveResponse(HttpRequestExecutor.java:300)
at org.apache.http.protocol.HttpRequestExecutor.execute(HttpRequestExecutor.java:127)
at org.apache.http.impl.client.DefaultRequestDirector.tryExecute(DefaultRequestDirector.java:715)
at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:520)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:906)
at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:805)
at    org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:784)
at com.tainosystems.http.client.TestWs.getInventory(TestWs.java:66)
at com.tainosystems.http.client.TestWs.main(TestWs.java:47)

现在，如果我使用WS网址并使用任何浏览器访问它，我都会得到预期的结果，但我想知道我的Apache HTTP客户端代码出了什么问题。

Answer 1

我从这里浏览了链接，并得到以下答案：
获得NoHttpResponseException以进行负载测试

那使我走上了正确的道路。要稍微更新一下答案，这里是使用当前http-client 4.5 API的解决方案：

private final HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory(createHttpClient());

private CloseableHttpClient createHttpClient() {
    return HttpClients.custom().setRetryHandler((exception, executionCount, context) -> {
            if (executionCount > 3) {
                LOGGER.warn("Maximum tries reached for client http pool ");
                return false;
            }
            if (exception instanceof org.apache.http.NoHttpResponseException) {
                LOGGER.warn("No response from server on " + executionCount + " call");
                return true;
            }
            return false;
        }).build();
}

我在那里也使用spring-web，所以我将客户端用作RestTemplate工厂的参数，因为我希望在RestTemplate中使用它。