java.io.IOException：尝试从关闭的流读取

Question

我使用Apache HTTP Client进行HTTPPost调用，然后尝试使用Jackson响应创建一个对象。这是我的代码：

private static final Logger log = Logger.getLogger(ReportingAPICall.class);
ObjectMapper mapper = new ObjectMapper();

public void makePublisherApiCall(String jsonRequest)
{
    String url = ReaderUtility.readPropertyFile().getProperty("hosturl");
    DefaultHttpClient client = new DefaultHttpClient();
    try {
        HttpPost postRequest = new HttpPost(url);
        StringEntity entity = new StringEntity(jsonRequest);
        postRequest.addHeader("content-type", "application/json");
        log.info("pub id :"+ExcelReader.publisherId);
        postRequest.addHeader("accountId", ExcelReader.publisherId);
        postRequest.setEntity(entity);
        HttpResponse postResponse = client.execute(postRequest);
        log.info(EntityUtils.toString(postResponse.getEntity()));

    //  Response<PublisherReportResponse> response = mapper.readValue(postResponse.getEntity().getContent(), Response.class);
    //  log.info("Reponse "+response.toString());
    } catch (UnsupportedEncodingException ex) {
        log.error(ex.getMessage());
        log.error(ex);
        Assert.assertTrue(false, "Exception : UnsupportedEncodingException");
    } catch (ClientProtocolException ex) {
        log.error(ex.getMessage());
        log.error(ex);
        Assert.assertTrue(false, "Exception : ClientProtocolException");
    } catch (IOException ex) {
        log.error(ex.getMessage());
        log.error(ex);
        Assert.assertTrue(false, "Exception : IOException");
    }

方法makePublisherApiCall（）将在一个循环中被调用，该循环运行100次。当我取消注释该行时，基本上会出现问题：

//  Response<PublisherReportResponse> response = mapper.readValue(postResponse.getEntity().getContent(), Response.class);
//  log.info("Reponse "+response.toString());

取消注释后，我得到异常：

Attempted read from closed stream.
17:26:59,384 ERROR com.inmobi.reporting.automation.reportingmanager.ReportingAPICall - java.io.IOException: Attempted read from closed stream.

否则，它将正常工作。有人可以让我知道我在做什么错。

Answer 1

什么是EntityUtils.toString(postResponse.getEntity())与响应实体呢？我会怀疑它正在消耗实体的内容流。该HttpClient的javadoc的状态，只有实体，这是重复的，可以多次消费。因此，如果实体不可重复，则无法将内容流再次提供给映射器。为避免这种情况，您只应让映射器使用流-
如果需要记录内容，则记录已解析的Response对象。