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File Handling(I/O-1)

FileWriter:-FileWriter is a sub class of OutputStreamWriter class and OutputStreamWriter class is sub class of Writer class which is abstract class. FileWriter class does not having own methods but it uses its parent class methods. It is a kind of writer used to write text data into destination file, this is character oriented writer, it is capable to create new file.

Example1:- TestFileWriter.java
import java.io.*;
class TestFileWriter
{
public static void main(String[]args)throws IOException
{
FileWriter fw=new FileWriter("abc.txt");
fw.write("Well-come to javaindore");
fw.flush();
}
}

Example2:- TestFileWriter.java
import java.io.*;
class TestFileWriter
{
public static void main(String[]args)throws IOException
{
FileWriter fw=new FileWriter("abc.txt");
fw.write("Well-come to javaindore");
fw.write('A');
fw.write(97);
fw.flush();
}
}
Output:-
Well-come to javaindoreAa

Example3:- TestFileWriter.java(appending data into file)
import java.io.*;
class TestFileWriter
{
public static void main(String[]args)throws IOException
{
FileWriter fw=new FileWriter("abc.txt",true);
fw.write("Well-come to javaindore");
fw.write('A');
fw.write(97);
fw.flush();
}
}
Output:-
Well-come to javaindoreAaWell-come to javaindoreAa

Example4:- TestReader.java
import java.io.*;
class TestReader
{
public static void main(String[]args)throws IOException
{
FileReader fr=new FileReader("abc.txt");
int i=fr.read();
while(i!=-1)
{
System.out.print((char)i);
i=fr.read();
}
}
}
Output:-
C:\JAVATECH>javac TestReader.java
C:\JAVATECH>java TestReader
Well-come to javaindoreAaWell-come to javaindoreAa

Example5:- TestReader.java(copy file)
import java.io.*;
class TestReader
{
public static void main(String[]args)throws IOException
{
FileReader fr=new FileReader("TestReader.java");
FileWriter fw=new FileWriter("abc1.txt");
int i=fr.read();
while(i!=-1)
{
System.out.print((char)i);
fw.write(i);
i=fr.read();
}
fw.flush();
}
}
Output:-
C:\JAVATECH>javac TestReader.java
C:\JAVATECH>java TestReader
import java.io.*;
class TestReader
{
public static void main(String[]args)throws IOException
{
FileReader fr=new FileReader("TestReader.java");
FileWriter fw=new FileWriter("abc1.txt");
int i=fr.read();
while(i!=-1)
{
System.out.print((char)i);
fw.write(i);
i=fr.read();
}
fw.flush();
}

}

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