How do I convert an InputStream to a String in Java?

Question

Suppose I have an InputStream that contains text data, and I want to convert this to a String (for example, so I can write the contents of the stre

Answer 1

A nice way to do this is using Apache commons IOUtils

IOUtils.toString(inputStream, string);

Answer 2

Below code might help you.

public String convertBytestoString(InputStream inputStream)
{
    int bytes;
    byte[] buffer = new byte[1024];

    bytes = inputStream.read(buffer);
    String stringData = new String(buffer,0,bytes);

    return stringData;

}

Answer 3

String text = new Scanner(inputStream).useDelimiter("\\A").next();

The only tricky is to remember the regex \A, which matches the beginning of input. This effectively tells Scanner to tokenize the entire stream, from beginning to (illogical) next beginning...
- from the Oracle Blog

Answer 4

With Java 9+ even shorter:

static String readString(InputStream inputStream) throws IOException {
   return new String(inputStream.readAllBytes(), StandardCharsets.UTF_8); // Or whatever encoding
}

Note: InputStream is not closed in this example.

Answer 5

If you want to do it simply and reliably, I suggest using the Apache Jakarta Commons IO library IOUtils.toString(java.io.InputStream, java.lang.String) method.

Answer 6

You can use a BufferedReader to read the stream into a StringBuilder in a loop, and then get the full contents from the StringBuilder:

public String convertStreamToString(InputStream is) { 
  BufferedReader reader = new BufferedReader(new InputStreamReader(is)); 
  StringBuilder sb = new StringBuilder(); 

  String line = null; 

  try { 
    while ((line = reader.readLine()) != null) { 
    sb.append(line + "\n"); 
    } 
  } catch (IOException e) { 
    e.printStackTrace(); 
  } finally { 
    try { 
      is.close(); 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
  }

  return sb.toString(); 
} 

Full disclosure: This is a solution I found on KodeJava.org. I am posting it here for comments and critique.