Java Tutorial

Java Tutorial Java Features C++ vs Java Java History Java Hello World Java Development Kit Java Runtime Environment Java Virtual Machine Difference between JDK, JRE, and JVM Memory Areas in Java Java Operators Java Keywords Primitive Data Types Variables

Java Loops

Java Do While Loop Java While Loop Java For Loop Java Enhanced For Loop

Java Programs

Java Basic Programs Factorial Program in Java Fibonacci Series Program in Java Prime Number Program in Java Palindrome Number Program in Java Armstrong Number Program in Java Anagram Program in Java Pattern Programs in Java Calculator Program in Java Leap Year Program in Java Addition Program in Java Number Pattern Programs in Java Star Pattern Programs in Java Package Program in Java Pyramid Program in Java Sorting Program in Java String Palindrome Program in Java Even Odd Program in Java For Loop Program in Java If Else Program in Java Switch Case Program in Java GCD Program in Java LCM Program in Java Hello Program in Java Matrix Program in Java Menu Driven Program in Java Series Program in Java Client Server Program in Java Swapping Program in Java Pig Latin Program in Java Tower of Hanoi Program in Java Recursion Program in Java Matrix Multiplication Program in Java Perfect Number Program in Java Classes and Objects in Java Example Programs String Programs in Java Array Programs in Java Constructor Program in Java Inheritance Program in Java Abstract class Program in Java Interface Program in Java Encapsulation Program in Java Polymorphism Program in Java Exception Handling Program in Java Multithreading Program in Java Thread Program in Java Collection Programs in Java ArrayList Program in Java Stack Program in Java Applet Program in Java Swing Program in Java JDBC Program in Java How to run Java program in command prompt How to run Java program in Eclipse

Java Sorting

Sorting Algorithms in Java Merge Sort in Java Quick Sort in Java Bubble Sort in Java Insertion Sort in Java Selection Sort in Java Heap Sort in Java Radix Sort in Java Topological Sort in Java Bucket Sort in Java Counting Sort in Java

Java OOPs Concepts

OOPs - Object Oriented Programming Objects and Classes in Java Java Naming Conventions Constructors in Java Java this keyword Java static keyword Inheritance in Java Aggregation in Java Java super keyword Constructor Chaining and Constructor Overloading Java Polymorphism Static and Dynamic Binding in Java Java Abstraction Abstract class in Java Interface in Java Difference between Abstract class and Interface Java final keyword Packages in Java Access Modifiers in Java Java Wrapper classes Java Numbers Java Characters Java Integer Java Boolean Java Arrays Java Command Line Arguments Java strictfp Keyword Java Math

Java Strings

Java Strings Java String Methods StringBuilder in Java StringBuffer in Java Java Regular Expressions StringBuffer vs StringBuilder String vs StringBuffer String vs StringBuilder String Manipulation in Java Java String Concatenation How to Reverse a String in Java String Array in Java How to Compare Two Strings in Java How to Concatenate Two Strings in Java Why String in Immutable in Java java.lang.NumberFormatException for Input String String Pool in Java Java Generate Random String How to take String Input in Java Java String Interview Questions

Java Exceptions

Exception Handling in Java Java try catch Java throw Java throws Difference between throw and throws Java finally Java Custom Exception Java Exception Propagation

Garbage Collection

Automatic Resource Management in Java Java Garbage Collection Java finalize() Java gc() Difference between final, finally and finalize


Multithreading in Java Process and Thread in Java Basic Terms in Multithreading Java Thread creation Thread Scheduler in Java Java Thread class DeadLock in Java

Java IO

Java IO Java Read File Java BufferedWriter Java InputStreamReader Java File Java Read File Line By Line Java FileOutputStream Jar File in Java


Java Serialization Java transient


Java Network Programming Java Socket Programming Java URL Java URLConnection HttpURLConnection in Java Java InetAddress Java DatagramSocket and Java DatagramPacket


Java AWT


Swing in Java

Java Collections

Collections in Java Java List Interface ArrayList in Java LinkedList in Java Vector in Java Stack in Java ArrayList vs LinkedList in Java ArrayList vs Vector in Java Java Set Interface HashSet in Java LinkedHashSet in Java TreeSet in Java Java Queue Interface PriorityQueue in Java ArrayDeque in Java Java Map Interface HashMap in Java LinkedHashMap in Java TreeMap in Java Dictionary in Java Hashtable in Java Properties in Java Collections class in Java Java Comparable Java Comparator Comparable vs Comparator in Java

Java Generics

Generics in Java

Java Annotations

Annotations in Java


Java JDBC Tutorial

Java Differences

Java vs JavaScript Python vs Java Kotlin vs Java Java vs C++ C# vs Java Static vs Non-static in Java C vs Java int vs Integer in Java Stack vs Heap in Java Java Array vs ArrayList

How to

How to run Java program How to set path in Java How to check the Java version in cmd How to install Java in Windows 10 How to run Java program in cmd How to call a method in Java How to sort an array in Java How to iterate HashMap in Java How to write Java program How to create an array in Java How to create a package in Java How to generate random numbers in Java How to input String in Java How to create thread in Java How to find length of String in Java How to sort a string in Java How to use scanner in Java How to achieve multiple inheritance in Java How to run Java program in Eclipse How to call a function in Java How to create array of objects in Java How to create custom exception in Java How to achieve abstraction in Java How to call static method in Java

Java 8 Features

Java 8 Features Lambda Expressions in Java Functional Interface in Java Streams in Java Java Base64 Encoding and Decoding Parallel Arrays Sort in Java

Java 9 Features

Java 9 Tutorial Java 9 Try With Resources Java 9 Interface Private Method

Java Servlet Tutorial

Java Servlets Tutorial

Java JSP Tutorial

Java JSP Tutorial

Hibernate Tutorial

Hibernate Tutorial

Spring Tutorial

Spring Tutorial

Spring MVC Tutorial

Spring MVC Tutorial

Jenkins Tutorial

Jenkins Tutorial

Java Math Methods

Math.abs() Math.acos() Math.addExact() Math.asin() Math.atan () Math.atan2() Math.cbrt() Math.ceil() Math.copysign() Math.cos() Math.cosh() Math.decrementExact() Math.exp() Math.expm1() Math.floor() Math.floorDiv() Math.floorMod() Math.getExponent() Math.hypot() Math.IEEEremainder() Math.incrementExact() Math.log() Math.log10() Math.log1p() Math.max() Math.min() Math.multiplyExact() Math.multiplyFull() Math.negateExact() Math.nextAfter() Math.nextDown() Math.nextUp() Math.pow() Math.random() Math.rint() Math.round() Math.scalb() Math.signum() Math.sin() Math.sinh() Math.sqrt() Math.subtractExact() Math.tan() Math.tanh() Math.toDegrees() Math.toIntExact() Math.toRadians() Math.ulp()

Java String Methods

toCharArray() copyValueOf() endsWith() equals() equalsIgnoreCase() format() getBytes() getChars() hashCode() indexOf() intern() isEmpty() join() lastIndexOf() length() replace() replaceAll() replaceFirst() split() startsWith() subSequence() substring() toLowerCase() toUpperCase() trim() valueOf()

Java Conversion

Java Convert String to int Java Convert int to String Java Convert String to long Java Convert long to String Java Convert String to float Java Convert float to String Java Convert String to double Java Convert double to String Java Convert String to Date Java Convert Date to String Java Convert String to Object Java Convert Object to String Java Convert String to char Java Convert char to String Java Convert int to long Java Convert long to int


Functional Interfaces in Java Singleton class in Java Awesome explanation of Strings in Java Object class in Java Static class in Java All the important string methods in Java String Handling Method in Java What are Array strings in Java Advantages and Disadvantages of Strings in Java Big Decimal class in Java Class definition in Java Char and String differences in Java Difference between String, StringBuffer and StringBuilder in java Replace character in string Java String Coding Interview Questions in Java What is String in Java? String isnullorempty in Java String Matches in Java Trim Method in String Java Bean class in Java Libraries in Java Arithmetic Operations on String in Java

Java FileOutputStream

What is FileOutputStream?

When we need raw stream data written into a file, we need to look for another option: FileOutputStream. It is used when the file's data is byte-oriented. It comes under the package and extends the abstract class Output stream. It implements the following interfaces, such as:

  • Closeable
  • Flushable
  • AutoCloseable

Why do we need FileOutputStream?

We utilize the File Writer and Buffered Writer classes to write text to a file. However, when there is a need to implement character-oriented classes, these classes do not allow binary data. And it was at this point that the requirement for FileOutputStream arose.

How to Use FileOutputStream

Following are the steps which demonstrate how to use FileOutputStream:

Importing the package is the first step in creating a FileOutputStream. Once the package has been imported, FileOutputStream can be implemented by following the point below.

1. Using the path of the file

FileOutputStream ot = new FileOutputStream(String path, boolean value);
FileOutputStream ot = new FileOutputStream(String path);

In the first line we created a FileOutputStream which has a reference variable ot. This FileOutputStream includes the boolean parameter.

In the Second line, we created a FileOutputStream, which also has a reference variable ot. This FileOutputStream does not include the boolean parameter.

The parameter path is the path of the file provided by the user while writing the program.

Additionally, value is a boolean parameter that can be left blank. The new data will be added to the end of the current data in the file if the Boolean is set to true. If not specified or used, the new data will overwrite the file's previous data.

2. Making use of a file's object

FileOutputStream to = new FileOutputStream(File object);

In the above code, we have created an output stream that will be linked to the specified file object.

Constructors of FileOutputStream

FileOutputStream has the following constructors, such as:

1. FileOutputStream(File fl): This constructor is implemented when there is a need to write to a file that is specified by the file object.


FileOutputStream ft = new FileOutputStream(File fl);

2. FileOutputStream(Filefl, boolean): This constructor is implemented when there is a need to write to a file specified by the file object, and it also has a boolean parameter.


FileOutputStream ft = new FileOutputStream(File fl, boolean a);

3. FileOutputStream(FileDescripterfobj): This constructor is used to build a file output stream for writing to the provided file descriptor, representing an existent file descriptor in the file system.


FileOutputStream fout = new FileOutputStream(FileDescripterfobj);

4. FileOutputStream(String n): This constructor is used when a file output stream object must be created to write to the file with the specified name.


FileOutputStream ft = new FileOutputStream( String n);

5. FileOutputStream(String n, boolean a): This constructor is used is used to build a file output stream object that will write to the provided file.


FileOutputStream ft = new FileOutputStream(String n, boolean a);

Methods of FileOutputStream

Following are the methods provided by FileOutputStream.

1void close() This method is implemented when there is a need to close the current file output stream and free all the resources related to the stream.
2protected void finalize()   This method is used when all connections to the file need to be cleaned up. It also makes sure that the close method is invoked so that no references are left that are related to the stream.
3FileChannelgetChannel() It’s a   return type method. It returns a FileChannel object that is unique to the current file output stream.
4FileDescriptorgetFD() This is a return type method and, when implemented, will return the file descriptor related to the present stream.
5void write(byte[ ] a) This method writes bytes with the specified byte array length to the present output stream.
6void write(byte[] a, into, int l) This method writes bytes with the length of the specified byte array, which starts at offset o to the present output stream.
7void write(int c) This method is implemented when there is a need to write the specified byte to the present output stream.
8flush() This method is implemented when there is a need to clear the present output stream. This method makes all data from the output stream to be written to the destination.


The FileOutputStream class is used to write data to a file in the following example. To write data to a file also requires creating a class object with the filename. The string's contents are stored and transformed to a byte array, which is then ( the content inside the byte array ) written to the file with the write() method. "Hello Everyone," is the text we'll write in the file.

public class a {
public static void main(String[] args) {
        String data = "Hello Everyone.";

        try {
            FileOutputStream output = new FileOutputStream("d://sample.txt");

            byte[] arr = data.getBytes();

System.out.println("code completed");


catch(Exception e) {


As we run the above code, we obtain the following output.

What is FileOutputStream?

We don't observe anything in the console, but we can see its text as we open the text file named sample.

What is FileOutputStream?