java read input from file code example

Example 1: java read file text

try(BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
    StringBuilder sb = new StringBuilder();
    String line = br.readLine();

    while (line != null) {
        sb.append(line);
        sb.append(System.lineSeparator());
        line = br.readLine();
    }
    String everything = sb.toString();
}

Example 2: reading from a text file in java

public static void main(String[] args) throws Exception 
  { 
    // pass the path to the file as a parameter 
    FileReader fr = new FileReader("C:\\Users\\pankaj\\Desktop\\test.txt"); 
  
    int i; 
    while ((i=fr.read()) != -1) 
      System.out.print((char) i); 
  }

Example 3: input file in java

import java.io.*;
public class CopyFile {

   public static void main(String args[]) throws IOException {  
      FileInputStream in = null;
      FileOutputStream out = null;

      try {
         in = new FileInputStream("input.txt");
         out = new FileOutputStream("output.txt");
         
         int c;
         while ((c = in.read()) != -1) {
            out.write(c);
         }
      }finally {
         if (in != null) {
            in.close();
         }
         if (out != null) {
            out.close();
         }
      }
   }
}