Store and Return String outside of While loop Java

Question


   BufferedReader br = new BufferedReader(new FileReader(fileLocation));
   String contentLine = br.readLine();
   while(contentLine!= null){
     System.out.println(contentLine);
     contentLine = br.readLine();

   }

   return contentLine; // returns null
 }

Hello All, I am in process of learning java, and here i am trying to parse a file that prints out the json message, the challenge I am facing is, I need to return that json which is inside while loop. Currently, the method returns null

I tried add the line of code return contentLine += br.readLine(); I throws an error at "+" saying expression expected — peter
– peter, Commented Nov 25, 2021 at 7:03
In your loop change contentLine = br.readLine(); to contentLine += br.readLine(); — Scary Wombat
– Scary Wombat, Commented Nov 25, 2021 at 7:04
@ScaryWombat if you do that, you'll never get out of the loop, though — Stultuske
– Stultuske, Commented Nov 25, 2021 at 7:07
@Stultuske true, i just tried that and its not coming out of loop. — peter
– peter, Commented Nov 25, 2021 at 7:08
@Peter keep your code as is, and store the data to return in a different variable — Stultuske
– Stultuske, Commented Nov 25, 2021 at 7:08

Scary Wombat · Accepted Answer · 2021-11-25 07:16:57Z

1

To cement the comments above, use a different variable and then append to the returned value

BufferedReader br = new BufferedReader(new FileReader(fileLocation));

StringBuilder contentLine = new StringBuilder ();
while(true){
     String tmp = br.readLine();
     if (tmp == NULL) {
         break;
     }
     contentLine.append (tmp);
     System.out.println(contentLine.toString ());
}

return contentLine.toString ();

answered Nov 25, 2021 at 7:16

Scary Wombat

44.9k6 gold badges38 silver badges67 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

peter Over a year ago

This worked, but the way its appending and completes the json is like this in console. { "page": { { "page": { "size": 2, { "page": { "size": 2, "number": 2, { "page": { "size": 2, "number": 2, "numberOfPages": 1,

Stultuske Over a year ago

you can always add a breakline each time you do .append(tmp);

Scary Wombat Over a year ago

@user16320675 - Absolutely agree, but just keeping with the original code.

Collectives™ on Stack Overflow

Store and Return String outside of While loop Java

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related