android httpclient 挂起对服务器的第二个请求(连接超时)

Question

我正在努力解决以下问题:我的应用程序使用 HttpClient 向 http 服务器发出一系列请求。我使用 HttpPut 向服务器发送数据。第一个请求进展顺利，第二个请求挂起 40 秒，然后我捕获 Connection timed out 异常。我正在尝试重用我的 HttpClient 并通过同一个实例发送第二个请求。如果我创建新的 HttpClient 和新的 ConnectionManager，那么一切正常。

为什么会这样？以及如何解决它而不是每次都创建新的HttpClient？

提前致谢。

这是我的代码:(如果我在 doPut 中注释 readClient = newHttpClient(readClient)，那么问题就出现了。

public class WebTest
{
private HttpClient readClient;
private SchemeRegistry httpreg;
private HttpParams params;

private URI url; //http://my_site.net/data/

protected HttpClient newHttpClient(HttpClient oldClient)
{
    if(oldClient != null)
        oldClient.getConnectionManager().shutdown();

    ClientConnectionManager cm = new SingleClientConnManager(params, httpreg);
    return new DefaultHttpClient(cm, params);
}

protected String doPut(String data)
{
    //****************************
    //Every time we need to send data, we do new connection
    //with new ConnectionManager and close old one
    readClient = newHttpClient(readClient);

    //*****************************


    String responseS = null;
    HttpPut put = new HttpPut(url);
    try
    {
        HttpEntity entity = new StringEntity(data, "UTF-8");
        put.setEntity(entity);
        put.setHeader("Content-Type", "application/json; charset=utf-8");
        put.setHeader("Accept", "application/json");
        put.setHeader("User-Agent", "Apache-HttpClient/WebTest");

        responseS = readClient.execute(put, responseHandler);
    }
    catch(IOException exc)
    {
        //error handling here
    }
    return responseS;
}

public WebTest()
{
    httpreg = new SchemeRegistry();
    Scheme sch = new Scheme("http", PlainSocketFactory.getSocketFactory(), 80);
    httpreg.register(sch);

    params = new BasicHttpParams();
    ConnPerRoute perRoute = new ConnPerRouteBean(10);
    ConnManagerParams.setMaxConnectionsPerRoute(params, perRoute);
    ConnManagerParams.setMaxTotalConnections(params, 50);
    ConnManagerParams.setTimeout(params, 15000);
    int timeoutConnection = 15000;
    HttpConnectionParams.setConnectionTimeout(params, timeoutConnection);
    // Set the default socket timeout (SO_TIMEOUT) 
    // in milliseconds which is the timeout for waiting for data.
    int timeoutSocket = 40000;
    HttpConnectionParams.setSoTimeout(params, timeoutSocket);
}

private ResponseHandler<String> responseHandler = new ResponseHandler<String>() 
{
    @Override
    public String handleResponse(HttpResponse response)
            throws ClientProtocolException, IOException
    {
        StatusLine statusLine = response.getStatusLine();
        if (statusLine.getStatusCode() >= 300) 
        {
            throw new HttpResponseException(statusLine.getStatusCode(),
                    statusLine.getReasonPhrase());
        }

        HttpEntity entity = response.getEntity();
        if(entity == null)
            return null;

        InputStream instream = entity.getContent();
        return this.toString(entity, instream, "UTF-8");
    }

    public String toString(
            final HttpEntity entity, 
            final InputStream instream, 
            final String defaultCharset) throws IOException, ParseException 
    {
        if (entity == null) 
        {
            throw new IllegalArgumentException("HTTP entity may not be null");
        }

        if (instream == null) 
        {
            return null;
        }
        if (entity.getContentLength() > Integer.MAX_VALUE) 
        {
            throw new IllegalArgumentException("HTTP entity too large to be buffered in memory");
        }
        int i = (int)entity.getContentLength();
        if (i < 0) 
        {
            i = 4096;
        }
        String charset = EntityUtils.getContentCharSet(entity);
        if (charset == null) 
        {
            charset = defaultCharset;
        }
        if (charset == null) 
        {
            charset = HTTP.DEFAULT_CONTENT_CHARSET;
        }

        Reader reader = new InputStreamReader(instream, charset);

        StringBuilder buffer=new StringBuilder(i);
        try 
        {
            char[] tmp = new char[1024];
            int l;
            while((l = reader.read(tmp)) != -1) 
            {
                buffer.append(tmp, 0, l);
            }
        } finally 
        {
            reader.close();
        }

        return buffer.toString();
    }
}; 

}

Answer 1

听起来您在处理完响应后没有使用实体。确保将以下代码放在 finally block 中:

if (httpEntity != null) {
    try {
        httpEntity.consumeContent();
    } catch (IOException e) {
        Log.e(TAG, "", e);
    }
}

我建议你阅读 HttpClient Tutorial .