checksumcrc32.java

this contains the source code for gui,servlet source code,mathematical funtions.

/*
 * ChecksumCRC32.java
 *
 * Created on July 24, 2008, 9:45 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

/**
 *
 * @author mekala
 */
import java.util.zip.CheckedInputStream;
//import java.security.interfaces.
import java.util.zip.CRC32;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;

public class ChecksumCRC32 {

    private static void doChecksum(String fileName) {

        try {

            CheckedInputStream cis = null;
            long fileSize = 0;
            try {
                // Computer CRC32 checksum
                cis = new CheckedInputStream(
                        new FileInputStream(fileName), new CRC32());

                fileSize = new File(fileName).length();
                
            } catch (FileNotFoundException e) {
                System.err.println("File not found.");
                System.exit(1);
            }

            byte[] buf = new byte[128];
            while(cis.read(buf) >= 0) {
            }

            long checksum = cis.getChecksum().getValue();
            System.out.println(checksum + " " + fileSize + " " + fileName+ " " + new CRC32().getValue());

        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }


    }


    /**
     * Sole entry point to the class and application.
     * @param args Array of String arguments.
     */
    public static void main(String[] args) {

        if (args.length != 0) {
            System.err.println("Usage: java ChecksumCRC32 filename");
        } else {
            doChecksum("D:"+java.io.File.separator+"Mekala.txt");
        }

    }

}