SHA1 the implementation of the file Request Information Digest

{Feature Description}
can be used to analyze whether the SHA1 value of the downloaded file is equal to the SHA1 value provided online.

{Code Implementation}

 PackageSup.orange.learn;ImportJava.io.FileInputStream;Importjava.io.IOException;Importjava.security.MessageDigest;Importjava.security.NoSuchAlgorithmException;/*** Created by Re-x on 11/4/14.*/ Public classHashfiletest { Public Static voidMain (string[] args)throwsIOException, nosuchalgorithmexception {Booleanresult = Verifychecksum ("/home/re-x/downloads/linux-1.0.tar.bz2", "4b3de322714d911c8bb46ceda2dbf541e6ab24f4"); System.out.println ("Does the file ' s checksum matches the expected one?" +result); }    /*** Verifies file ' s SHA1 checksum. * @paramfile, filepath and namd of a file, is verified. * @paramTestchecksum, the expected checksum. * @returntrue if the expeceted SHA1 checksum matches the file ' s SHA1 checksum; false otherwise *@throwsjava.security.NoSuchAlgorithmException *@throwsjava.io.IOException*/     Public Static BooleanVerifychecksum (string file, String testchecksum)throwsnosuchalgorithmexception, IOException {messagedigest messagedigest= Messagedigest.getinstance ("SHA1"); FileInputStream FIS=Newfileinputstream (file); byte[] data =New byte[1024]; intRead = 0;  while(read = Fis.read (data))! =-1) {messagedigest.update (data,0, read); }        byte[] Hashbytes =messagedigest.digest (); StringBuffer SB=NewStringBuffer ();  for(inti = 0; i < hashbytes.length; i++) {sb.append (integer.tostring (hashbytes[i)& 0xff) + 0x100, +). SUBSTRING (1)); } String Filehash=sb.tostring (); System.out.println (File+ "SHA1 is:" +Filehash); returnfilehash.equals (testchecksum); }}

SHA1 the implementation of the file Request Information Digest