Java program loads a file as InputStream

Comprehensive Java Examples

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

To understand this example, you should be familiar with the followingJava programmingTopic:

• Java InputStream class

• Java FileInputStream class

Example1: 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 {
　　　　　　//The file input.txt is loaded as an input stream
　　　　　　//　Content of input.txt file:
　　　　　　//This is the content of the file input.txt.
　　　　　　InputStream input = new FileInputStream("input.txt");
　　　　　　System.out.println("Data in the file: ");
　　　　　　//Read the first byte
　　　　　　int i = input.read();
　　　　　　while(i !=　-1) {
　　　　　　　　System.out.print((char)i);
　　　　　　　　//Read the next byte from the file
　　　　　　　　i = input.read();
　　　　　　}
　　　　　　input.close();
　　　　}
　　　　catch(Exception e) {
　　　　　　e.getStackTrace();
　　　　}
　　}
}

Output Result

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

In the above example, we have a file namedinput.txtThe content of the file is

This is the content of the file input.txt.

Here, we use the FileInputStream class to loadinput.txtLoad the file as an input stream and then use the read() method to read all the data from the file.

Example2: Java program to load a file as InputStream

Suppose we have a file namedTest.javaJava file,

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

We can also load this Java file as an input stream.

import java.io.InputStream;
import java.io.FileInputStream;
public class Main {
　　public static void main(String args[]) {
　　　　try {
　　　　　　//　Load the file Test.java as an input stream
　　　　　　InputStream input = new FileInputStream("Time.java");
　　　　　　System.out.println("Data in the file: ");
　　　　　　//　Read the first byte
　　　　　　int i = input.read();
　　　　　　while(i !=　-1) {
　　　　　　　　System.out.print((char)i);
　　　　　　　　//　Read the next byte from the file
　　　　　　　　i = input.read();
　　　　　　}
　　　　　　input.close();
　　　　}
　　　　catch(Exception e) {
　　　　　　e.getStackTrace();
　　　　}
　　}
}

Output Result

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

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

Comprehensive Java Examples