source: java/installer2/src/net/oni2/aeinstaller/backend/FileChecksum.java@ 925

package net.oni2.aeinstaller.backend;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * @author Christian Illy
 */
public class FileChecksum {

        /**
         * Calculate MD5 checksum of file
         * 
         * @param f
         *            File to calc checksum on
         * @return Checksum
         */
        public static byte[] calculateFileMD5(File f) {
                MessageDigest md = null;
                InputStream is = null;
                InputStream dis = null;
                byte[] md5 = null;
                try {
                        md = MessageDigest.getInstance("MD5");
                        is = new FileInputStream(f);
                        dis = new DigestInputStream(is, md);
                        byte data[] = new byte[1024];
                        while (dis.read(data) > 0) {
                        }
                        md5 = md.digest();
                } catch (NoSuchAlgorithmException e) {
                        e.printStackTrace();
                } catch (FileNotFoundException e) {
                        e.printStackTrace();
                } catch (IOException e) {
                        e.printStackTrace();
                } finally {
                        if (dis != null) {
                                try {
                                        dis.close();
                                } catch (IOException e) {
                                        e.printStackTrace();
                                }
                        }
                }
                return md5;
        }

}