File Reader: inherits from the InputStreamReader class. FileReader is used for reading streams of characters.
This class has several constructors to create required objects.
Following syntax creates a new FileReader, given the File to read from.
Following syntax creates a new FileReader, given the FileDescriptor to read from.
FileReader(FileDescriptor fd) |
Following syntax creates a new FileReader, given the name of the file to read from.
FileReader(String fileName) |
Once you have
FileReader object in hand then there is a list of helper methods which can be used manipulate the files.
| SN | Methods with Description |
| 1 | public int read() throws IOException
Reads a single character. Returns an int, which represents the character read. |
| 2 | public int read(char [] c, int offset, int len)
Reads characters into an array. Returns the number of characters read. |
Example:
Following is the example to demonstrate class:
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();
}
} |
This would produce following result:
No comments:
Post a Comment