如何控制okHttpClient连接大小？

Question

    OkHttpClient okHttpClient = new OkHttpClient().setConnectTimeout(TIMEOUT);
    ConnectionPool connectionPool = new ConnectionPool(MAX_IDLE_CONNECTIONS,
                                                       KEEP_ALIVE_DURATION_MS);
    okHttpClient.set(connectionPool);

    @RequireArgsConstructor
    public HttpEngineCallable implements Callable<IHttpResponse>
    {
      private final String url;

      public IHttpResponse call () throws Exception 
      {
         try
        {
           Request request = Request.Builder().url(url).build();
           Call call = okHttpClient.newCall(request);
           Response rawResponse = call.execute();
           return new OkHttpResponse(rawResponse);
        }
        catch (Exception e)
        {
           throw new IllegalStateException(e);
        }
    }  

    private final Function<IHttpResponse, T> httpResponseParser = new Function<IHttpResponse, T>()
    {
        @Nullable
        @Override
        public T apply(@Nullable IHttpResponse httpResponse)
        {
            if(httpResponse == null)
            {
               return null;
            }

            InputStream stream = httpResponse.getBody();
            JsonParser parser = null;
            T result = null;

            try
            {
               parser = jsonFactory.createParser(stream);
               result = strategy.parseData(parser);
            }
            catch (Exception e)
            {
               log.error("Unable to convert {} with {}.", stream, strategy, e);
            }
            finally
            {
               IOUtils.closeQuietly(parser);
               IOUtils.closeQuietly(stream);
            } 

          return result;
        }
     };

     Future<T> future = executorService.submit(new HttpEngineCallable(url));
     Future<V> finalFuture = Futures.transform(future, httpResponseParser, executorService);

     T result = timeoutExecutorService.submit(new Runnable() 
     {
        try
        { 
          T result = finalFuture.get(CLIENT_TIMEOUT, TIMEUNIT)
          if (result == null)
          { 
            notify onFailure listeners
          }
          else
          {
            notify onSuccess Listeners
          }
        }
        catch(Exception ex)
        {
          notify onFailure listeners
        }
     } 

所以我有几个关于这个实现的问题：

1. 我的CLIENT_TIMEOUT比OkHttp ConnectTimeout短。如果我的finalfuture.get(CLINT_TIMEOUT,TIMEUNIT)抛出超时异常，解析器函数中的finally block还会执行吗？我指望它能关闭我的联系。
2. 如何限制连接池的大小？如果连接超出限制，有没有办法自动回收最旧的连接？

Answer 1

我们有一个类似的问题，太多打开的文件描述符使我们的应用程序崩溃。

问题是我们为每个请求创建了一个OkHttpClient。默认情况下，每个OkHttpClient都有自己的连接池，这当然会增加连接/线程/文件句柄的数量，并阻止池中的适当重用。

我们解决了这个问题，方法是在单例中手动创建一个全局ConnectionPool,然后将其传递给构建实际OKHttpClient的OKHttpClient的OKHttpClient对象。

...
builder.connectionPool(GLOBAL_CONNECTION_POOL);
OkHttpClient client = builder.build();
...