如何限制HttpClient响应长度 [英] How to limit HttpClient response length

问题描述

我正在将htmlunit与httpclient一起使用.如何限制httpclient的response body length说1MB?

I'm using htmlunit with httpclient. How can I limit the response body length of httpclient to say 1MB?

推荐答案

技巧很简单.您必须获取InputStream并从中读取，并在超出限制时停止读取.

The trick is easy. You have to take the InputStream,read from it and stop reading when the limit is exceeded.

      InputStream instream = method.getResponseBodyAsStream();

我已经完成了一个示例，对Apache示例进行了一些调整.

I have done an example tuning the apache example a bit.

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;
import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;
public class HttpClientTutorial {

  private static String url = "http://www.apache.com";
  private static final int LIMIT = 1024*1024;//set to 1MB
  public static void main(String[] args) {
    // Create an instance of HttpClient.
    HttpClient client = new HttpClient();
    // Create a method instance.
    GetMethod method = new GetMethod(url);   
    // Provide custom retry handler is necessary
    method.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, 
            new DefaultHttpMethodRetryHandler(3, false));
    try {
      // Execute the method.
      int statusCode = client.executeMethod(method);
      if (statusCode != HttpStatus.SC_OK) {
        System.err.println("Method failed: " + method.getStatusLine());
      }
      // Read the response body.
      //byte[] responseBody = method.getResponseBody();
      byte[] responseBody = null;    
      InputStream instream = method.getResponseBodyAsStream();
      if (instream != null) {
          long contentLength = method.getResponseContentLength();
          if (contentLength < Integer.MAX_VALUE) { //guard below cast from overflow
              ByteArrayOutputStream outstream = new ByteArrayOutputStream();
              byte[] buffer = new byte[1024];
              int len;
              int total = 0;
              while ((len = instream.read(buffer)) > 0 && total<LIMIT) {
                  outstream.write(buffer, 0, len);
                  total+= len;
              }
              responseBody = outstream.toByteArray();
              outstream.close();
              instream.close();
              System.out.println(new String(responseBody));
          }
      }
    } catch (HttpException e) {
      System.err.println("Fatal protocol violation: " + e.getMessage());
      e.printStackTrace();
    } catch (IOException e) {
      System.err.println("Fatal transport error: " + e.getMessage());
      e.printStackTrace();
    } finally {
      // Release the connection.
      method.releaseConnection();
    }  
  }
}

我希望这会有所帮助.

这篇关于如何限制HttpClient响应长度的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！