Read a few lines from InputStreamReader (JAVA)

Question

I have an InputStreamReader object. I want to read multiple lines in a buffer / array using a single function call (without breaking the array of string objects). Is there an easy way to do this?

Answer 1

First of all, remember that it is InputStreamReadernot so effective, you should wrap it around the object BufferedReaderfor maximum performance.

With that in mind, you can do something like this:

public String readLines(InputStreamReader in)
{
  BufferedReader br = new BufferedReader(in);
  // you should estimate buffer size
  StringBuffer sb = new StringBuffer(5000);

  try
  {
    int linesPerRead = 100;
    for (int i = 0; i < linesPerRead; ++i)
    {
      sb.append(br.readLine());
      // placing newlines back because readLine() removes them
      sb.append('\n');
    }
  }
  catch (Exception e)
  {
    e.printStackTrace();
  }

  return sb.toString();
}

Note that the readLine()return nullis EOF, so you should check and take care of it.

Answer 2

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