File Writer

Class FileWriter

java.lang.Object
  java.io.Writer
      java.io.OutputStreamWriter
          java.io.FileWriter

All Implemented Interfaces:

Closeable, Flushable, Appendable

File Writer object is used to write character data into a file

Constructors:

Lets see the constructor's available in FileWriter class

1. FileWriter fw=new FileWriter(String name);

    /* Constructs a FileWriter object given a file name*/

2. FileWriter fw=new FileWriter(String name, boolean append);

    /* Constructs a FileWriter object given a File object.*/

3. FileWriter fw=new FileWriter(File f);

    /* Constructs a FileWriter object given a File object.*/

4. FileWriter fw=new FileWriter(File f, boolean append);

   /*Constructs a FileWriter object given a file name with a boolean indicating whether or not to append the data written*/

5. FileWriter fw=new FileWriter(fileDescriptor fd);

   /* Constructs a FileWriter object associated with a file descriptor*/

Method Summary

 

Methods inherited from class java.io.OutputStreamWriter
close, flush, getEncoding, write, write, write

 

Methods inherited from class java.io.Writer
append, append, append, write, write

 

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

 

Most Frequently Used Methods

1. write (int char) : To write a single character to the file.

2. write (String s) : To write a string to the file.

3. write (char [] ch) : To write all the characters present in the char [].

4. flush() : To make sure data is added to the file.

5. close() : Close the file.

Now lets see the functionality of the above methods with an example

package com.java.everythingaboutselenium;

import java.io.*;

public class FileRead{

   public static void main(String args[])throws IOException{

      File file = new File("Hello1.txt");

      // creates the file

      file.createNewFile();

      // creates a FileWriter Object

      FileWriter writer = new FileWriter(file); 

      // Writes the content to the file

      writer.write("This\n is\n an\n example\n"); 

      writer.flush();

      writer.close();

      //Creates a FileReader Object

      FileReader fr = new FileReader(file); 

      char [] a = new char[50];

      fr.read(a); // reads the content to the array

      for(char c : a)

          System.out.print(c); //prints the characters one by one

      fr.close();

   }

}