java.io.IOException: Attempted read from closed stream

前言：

代码如下，执行的时候提示“java.io.IOException: Attempted read from closed stream.”

public static JSONObject post(String url,StringBuffer params,String token ){

        CloseableHttpClient httpClient = HttpClientBuilder.create().build();
        HttpPost httpPost = new HttpPost(url + "?" + params);
        httpPost.setHeader("Content-Type", "application/json, text/plain, */*");
        httpPost.setHeader("Authorization",token);

        // 响应模型
        CloseableHttpResponse response = null;
        try {
            // send the Post Request
            response = httpClient.execute(httpPost);
            HttpEntity responseEntity = response.getEntity();
           if (responseEntity != null) {
                System.out.println("响应内容长度为:" + responseEntity.getContentLength());
                System.out.println("响应内容为:" + EntityUtils.toString(responseEntity));
                String jsonString = EntityUtils.toString(responseEntity);
                resBody = JSONObject.fromObject(jsonString);
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            //release resource
            release(httpClient,response);
        }
        return resBody;
    }

原因

response.getEntity()所得到的流是不可重复读取的，所得的实体只能读取一次,读取一次后,流就关闭了。EntityUtils.toString(responseEntity)被调用一次后就会自动销毁，而我调用了2次，所以就报错了。

System.out.println("响应内容为:" + EntityUtils.toString(responseEntity));
String jsonString = EntityUtils.toString(responseEntity);

解决方法

把这2个输出脚本改为如下即可，只要调用一次就好:

  String jsonString = EntityUtils.toString(responseEntity);
  System.out.println("响应内容为:" + jsonString);