Byron Kiourtzoglou

About Byron Kiourtzoglou

Byron is a master software engineer working in the IT and Telecom domains. He is always fascinated by SOA, middleware services and mobile development. Byron is co-founder and Executive Editor at Java Code Geeks.

Read file in byte array with FileInputStream

This is an example of how to read a File in a byte array using a FileInputStream. The FileInputStream obtains input bytes from a file in a file system. Reading a file in a byte array with a FileInputStream implies that you should:

  • Create a new File instance by converting the given pathname string into an abstract pathname.
  • Create a FileInputStream by opening a connection to an actual file, the file named by the path name name in the file system.
  • Create a byte array with size equal to the file length.
  • Use read(byte[] b) API method of FileInputStream to read up to certain bytes of data from this input stream into the byte array.
  • Create a String from the byte array.
  • Don’t forget to close the FileInputStream, using the close() API method.

Let’s take a look at the code snippet that follows:

package com.javacodegeeks.snippets.core;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class ReadFileInByteArrayWithFileInputStream {
	
	public static void main(String[] args) {
		
		File file = new File("inputfile.txt");
		FileInputStream fin = null;
		try {
			// create FileInputStream object
			fin = new FileInputStream(file);

			byte fileContent[] = new byte[(int)file.length()];
			
			// Reads up to certain bytes of data from this input stream into an array of bytes.
			fin.read(fileContent);
			//create string from byte array
			String s = new String(fileContent);
			System.out.println("File content: " + s);
		}
		catch (FileNotFoundException e) {
			System.out.println("File not found" + e);
		}
		catch (IOException ioe) {
			System.out.println("Exception while reading file " + ioe);
		}
		finally {
			// close the streams using close method
			try {
				if (fin != null) {
					fin.close();
				}
			}
			catch (IOException ioe) {
				System.out.println("Error while closing stream: " + ioe);
			}
		}
	}
}

 
This was an example of how to read a file in a byte array with a FileInputStream in Java.

Do you want to know how to develop your skillset to become a Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you two of our best selling eBooks for FREE!

JPA Mini Book

Learn how to leverage the power of JPA in order to create robust and flexible Java applications. With this Mini Book, you will get introduced to JPA and smoothly transition to more advanced concepts.

JVM Troubleshooting Guide

The Java virtual machine is really the foundation of any Java EE platform. Learn how to master it with this advanced guide!

Given email address is already subscribed, thank you!
Oops. Something went wrong. Please try again later.
Please provide a valid email address.
Thank you, your sign-up request was successful! Please check your e-mail inbox.
Please complete the CAPTCHA.
Please fill in the required fields.
Examples Java Code Geeks and all content copyright © 2010-2014, Exelixis Media Ltd | Terms of Use | Privacy Policy | Contact
All trademarks and registered trademarks appearing on Examples Java Code Geeks are the property of their respective owners.
Java is a trademark or registered trademark of Oracle Corporation in the United States and other countries.
Examples Java Code Geeks is not connected to Oracle Corporation and is not sponsored by Oracle Corporation.
Do you want to know how to develop your skillset and become a ...
Java Rockstar?

Subscribe to our newsletter to start Rocking right now!

To get you started we give you two of our best selling eBooks for FREE!

Get ready to Rock!
You can download the complementary eBooks using the links below:
Close