javamd5实例

import java.io.*;
import java.security.*;

public class Demo1 {

	/**
	 * @param args
	 * @throws Exception 
	 */
	public static void main(String[] args) throws Exception {
		String str = "hello";
		
		String md5Str = getMD5Str(str);
		System.out.println(md5Str);
	}
	
	public static String getMD5Str(String str) {  
        MessageDigest messageDigest = null;  
  
        try {  
            messageDigest = MessageDigest.getInstance("MD5");  
  
            messageDigest.reset();  
  
            messageDigest.update(str.getBytes("UTF-8"));  
        } catch (NoSuchAlgorithmException e) {  
            System.out.println("NoSuchAlgorithmException caught!");  
            System.exit(-1);  
        } catch (UnsupportedEncodingException e) {  
            e.printStackTrace();  
        }  
  
        byte[] byteArray = messageDigest.digest();  
  
        StringBuffer md5StrBuff = new StringBuffer();  
  
        for (int i = 0; i < byteArray.length; i++) {              
            if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)  
                md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));  
            else  
                md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));  
        }  
  
        return md5StrBuff.toString();  
    } 
}