Java - Read line using InputStream [duplicate]

Question

I use InputStream to read some data, so I want to read characters until new line or '\n'.

Answer 1

You should use BufferedReader with FileInputStreamReader if your read from a file

BufferedReader reader = new BufferedReader(new FileInputStreamReader(pathToFile)); 

or with InputStreamReader if you read from any other InputStream

BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream)); 

Then use its readLine() method in a loop

while(reader.ready()) {      String line = reader.readLine(); } 

But if you really love InputStream then you can use a loop like this

InputStream stream;  char c;  String s = "";  do {    c = stream.read();     if (c == '\n')       break;     s += c + ""; } while (c != -1); 

Answer 2

TL;DR

Use BufferedReader within the try-with block, which will close the resource after finishing with it.

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It is possible to read the input stream with BufferedReader and with Scanner. If you don't have a good reason, it is better to use BufferedRead (for broad discussion BufferedReader vs Scanner see).

I would also suggest using the Buffered Reader with try-with-resources to make sure the resource are auto-closed. see

See the following code

try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream))) {         while (reader.ready()) {             String line = reader.readLine();             System.out.println(line);         }     }catch (FileNotFoundException e) {         // TODO Auto-generated catch block         e.printStackTrace();     } catch (IOException e) {         // TODO Auto-generated catch block         e.printStackTrace();     }