Question

We usually get data from server response in android development.

/*
* get server response inputStream
*/
InputStream responseInputStream;

Solution1: get response string by multiple read.

      /*
       * get server response string
      */
    StringBuffer responseString = new StringBuffer();
    responseInputStream = new InputStreamReader(conn.getInputStream(),"UTF-8");

    char[] charBuffer = new char[bufferSize];
    int _postion = 0;
    while ((_postion=responseInputStream.read(charBuffer)) > -1) {
        responseString.append(charBuffer,0,_postion);
        }
    responseInputStream.close();

Solution2: get response only one read.

String responseString = null;
int content_length=1024;
// we can get content length from response header, here assign 1024 for simple.
responseInputStream = new InputStreamReader(conn.getInputStream(),"UTF-8");

char[] charBuffer = new char[content_length];
int _postion = 0;
int position = responseInputStream.read(charBuffer)
if(position>-1){
   responseString = new String(charBuffer,0,position );
 }
responseInputStream.close();

Which solution has better performance? why?

Notes: server response json format data that less than 1M bytes.

Answer 1

Why you’re reinventing a wheel? 😉

If you’re using HttpClient then just use EntityUtils.toString(...).
I guess you’re using HttpURLConnection. Then look at EntityUtils.toString(...) from Apache HttpClient – source code. Your first approach is similar to it.

BTW, the second code is worse because:

new String(charBuffer,0,position ) runs garbage collector

In both and even in EntityUtils:

int content_length = 1024; in most cases 8192 is default for socket buffer, so your code might run while loop 8 times more often than it could.