How can I get an HTTP response body as a string?

Question

Here are two examples from my working project.

1. Using EntityUtils and HttpEntity

   HttpResponse response = httpClient.execute(new HttpGet(URL));
   HttpEntity entity = response.getEntity();
   String responseString = EntityUtils.toString(entity, "UTF-8");
   System.out.println(responseString);
   

2. Using BasicResponseHandler

   HttpResponse response = httpClient.execute(new HttpGet(URL));
   String responseString = new BasicResponseHandler().handleResponse(response);
   System.out.println(responseString);
   

Every library I can think of returns a stream. You could use IOUtils.toString() from Apache Commons IO to read an InputStream into a String in one method call. E.g.:

URL url = new URL("http://www.example.com/");
URLConnection con = url.openConnection();
InputStream in = con.getInputStream();
String encoding = con.getContentEncoding();
encoding = encoding == null ? "UTF-8" : encoding;
String body = IOUtils.toString(in, encoding);
System.out.println(body);

Update: I changed the example above to use the content encoding from the response if available. Otherwise it'll default to UTF-8 as a best guess, instead of using the local system default.

Here's an example from another simple project I was working on using the httpclient library from Apache:

String response = new String();
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(1);
nameValuePairs.add(new BasicNameValuePair("j", request));
HttpEntity requestEntity = new UrlEncodedFormEntity(nameValuePairs);

HttpPost httpPost = new HttpPost(mURI);
httpPost.setEntity(requestEntity);
HttpResponse httpResponse = mHttpClient.execute(httpPost);
HttpEntity responseEntity = httpResponse.getEntity();
if(responseEntity!=null) {
    response = EntityUtils.toString(responseEntity);
}

just use EntityUtils to grab the response body as a String. very simple.

This is relatively simple in the specific case, but quite tricky in the general case.

HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet("http://stackoverflow.com/");
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
System.out.println(EntityUtils.getContentMimeType(entity));
System.out.println(EntityUtils.getContentCharSet(entity));

The answer depends on the Content-Type HTTP response header.

This header contains information about the payload and might define the encoding of textual data. Even if you assume text types, you may need to inspect the content itself in order to determine the correct character encoding. E.g. see the HTML 4 spec for details on how to do that for that particular format.

Once the encoding is known, an InputStreamReader can be used to decode the data.

This answer depends on the server doing the right thing - if you want to handle cases where the response headers don't match the document, or the document declarations don't match the encoding used, that's another kettle of fish.

Below is a simple way of accessing the response as a String using Apache HTTP Client library.

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.BasicResponseHandler;

//... 

HttpGet get;
HttpClient httpClient;

// initialize variables above

ResponseHandler<String> responseHandler = new BasicResponseHandler();
String responseBody = httpClient.execute(get, responseHandler);

The Answer by McDowell is correct one. However if you try other suggestion in few of the posts above.

HttpEntity responseEntity = httpResponse.getEntity();
if(responseEntity!=null) {
   response = EntityUtils.toString(responseEntity);
   S.O.P (response);
}

Then it will give you illegalStateException stating that content is already consumed.

How about just this?

org.apache.commons.io.IOUtils.toString(new URL("http://www.someurl.com/"));