Java: Read a file line by line and store it into a variable

Last update on April 28 2025 07:37:14 (UTC/GMT +8 hours)

Write a Java program to read a file line by line and store it in a variable.

Sample Solution:

Java Code:

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.FileReader;
 
public class exercise13 {
 
    public static void main(String a[]){
        StringBuilder sb = new StringBuilder();
        String strLine = "";
        String str_data = "";
        try {
             BufferedReader br = new BufferedReader(new FileReader("/home/students/test.txt"));
             while (strLine != null)
             {
                if (strLine == null)
                  break;
                str_data += strLine;
                strLine = br.readLine();
                
            }
              System.out.println(str_data);
             br.close();
        } catch (FileNotFoundException e) {
            System.err.println("File not found");
        } catch (IOException e) {
            System.err.println("Unable to read the file.");
        }
     }
}

Sample Output:

Welcome to w3resource.com.Append this text.Append this text.Append this text.Append this text.Append this text
.Append this text.Append this text.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to read the entire content of a file into a single String variable.
• Write a Java program to store file contents in a variable and then search for a specific substring within it.
• Write a Java program to read a text file into a variable and count the number of occurrences of a given word.
• Write a Java program to load a file's content into a variable and then split the text based on a delimiter.

Java Code Editor:

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