Encrypting files and strings using Java MD5

Cryptographic tool Classes

package com.kaige123.util;import java.io.file;import java.io.fileinputstream;import  Java.io.ioexception;import java.nio.mappedbytebuffer;import java.nio.channels.filechannel;import &NBSP;JAVA.SECURITY.MESSAGEDIGEST;/**&NBSP;*MD5 text and file encryption <br> *http://www.kaige123.com * @author   Edith   */public class MD5Util {         &NBSP;//16 binary          protectedstatic char hex[] =  {                              ' 0 ', ' 1 ',  ' 2 ',  ' 3 ',  ' 4 ',  ' 5 ',  ' 6 ', ' 7 ',  ' 8 ',  ' 9 ',  ' A ',  ' B ',  ' C ',  ' D ',  ' E ',  ' F '};          protectedstatic messagedigest messagedigest =  null;         static{                    try{                             // Get MD5 Instances                              messagedigest=  Messagedigest.getinstance ("MD5");                    }catch  (exception e)  {                    }          }         //get file MD5 key           publicStatic string getfilemd5string (File file)  throws IOException {                     Fileinputstreamin = new fileinputstream (file);                    filechannelch = in.getchannel ();                     MappedByteBufferbyteBuffer =                                       ch.map (filechannel.mapmode.read_only,0,                              &Nbsp;        file.length ());                    messagedigest.update (ByteBuffer);                     returnbuffertohex (Messagedigest.digest ());         }          //get MD5 string key           publicstatic string getmd5string (string s)  {                    returngetmd5string (S.getBytes ()) ;         }          Publicstatic string getmd5string (byte[] bytes)  {                    messagedigest.update (bytes);                    returnbuffertohex ( Messagedigest.digest ());         }          privatestatic string buffertohex (byte bytes[])  {                     Returnbuffertohex (bytes, 0, bytes.length);          }          privatestatic string buffertohex (byte  Bytes[], int m, int n)  {                    StringBufferstringbuffer = new  StringBuffer (2 * n);                   intk = m  + n;                    for (int l = m; l < k; l++)  {                              appendhexpair (Bytes[l],stringbuffer);                    }                     Returnstringbuffer.tostring ();         }          privatestatic void appendhexpair (byte bt, stringbuffer  StringBuffer)  {                   charc0 =  hex[(bt & 0xf0)  >> 4];                    charc1 = hex[bt &  0xf];                    stringbuffer.append (C0);                    stringbuffer.append (C1);          }}

test class

package com.kaige123.util;import java.io.file;import java.io.ioexception;/** *  Test class  * @author   Edith  */public class Test {          publicstatic void main (String[] args)  throws IOException {                    // Get string md5                    stringmd5str=md5util.getmd5string ("Edith is a Fat Man");                    system.out.println (MD5STR);                             //Get the file md5                &nBsp;   stringfilemd5str=md5util.getfilemd5string (New file ("C:/kaige/a.txt"));                     System.out.println (FILEMD5STR);          }}

Encrypting files and strings using Java MD5