Java Program to Load File as InputStream

Java Program to Load File as InputStream

In this example, we will learn to load a file as an input stream using the FileInputStream class in Java.

Example 1: Java Program to Load a Text File as InputStream

import java.io.InputStream;
import java.io.FileInputStream;

public class Main {

  public static void main(String args[]) {

    try {

      // file input.txt is loaded as input stream
      // input.txt file contains:
      // This is a content of the file input.txt
      InputStream input = new FileInputStream("input.txt");

      System.out.println("Data in the file: ");

      // Reads the first byte
      int i = input.read();

      while(i != -1) {
        System.out.print((char)i);

        // Reads next byte from the file
        i = input.read();
      }
      input.close();
    }

    catch(Exception e) {
      e.getStackTrace();
    }
  }
}

Output

Data in the file: 
This is a content of the file input.txt.

In the above example, we have a file named input.txt. The content of the file is

This is a content of the file input.txt.

Here, we used the FileInputStream class to load the input.txt file as input stream. We then used the read() method to read all the data from the file.


Example 2: Java Program to Load Java File as InputStream

Consider we have a Java file named Test.java,

class Test {
  public static void main(String[] args) {
    System.out.println("This is Java File");
  }
}

We can also load this Java file as input stream.

import java.io.InputStream;
import java.io.FileInputStream;

public class Main {

  public static void main(String args[]) {

    try {

      // file Test.java is loaded as input stream
      InputStream input = new FileInputStream("Time.java");

      System.out.println("Data in the file: ");

      // Reads the first byte
      int i = input.read();

      while(i != -1) {
        System.out.print((char)i);

        // Reads next byte from the file
        i = input.read();
      }
      input.close();
    }

    catch(Exception e) {
      e.getStackTrace();
    }
  }
}

Output

Data in the file: 
class Test {
  public static void main(String[] args) {  
    System.out.println("This is Java File");
  }
}

In the above example, we have used the FileInputStream class to load the Java file as an input stream.


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