Java - FileReader Class
This class 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.
FileReader(File file)
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 the following result:
This is an example