import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Test{
	public static void main(String[] args) {
		Md5("123456") ;
		//结果
		//    result: e10adc3949ba59abbe56e057f20f883e
		//    result: 49ba59abbe56e057

	}
	private static String Md5(String plainText ) { 
		try { 
			MessageDigest md = MessageDigest.getInstance("MD5"); 
			md.update(plainText.getBytes()); 
			byte b[] = md.digest(); 
			int i; 
			StringBuffer buf = new StringBuffer(""); 
			for (int offset = 0; offset < b.length; offset++) { 
			i = b[offset]; 
			if(i<0) i+= 256; 
			if(i<16) 
			buf.append("0"); 
			buf.append(Integer.toHexString(i)); 
			} 
	
			System.out.println("result: " + buf.toString());//32位的加密 
	
			System.out.println("result: " + buf.toString().substring(8,24));//16位的加密 
			return buf.toString() ;
		} catch (NoSuchAlgorithmException e) { 
			e.printStackTrace(); 
			return null ;
		} 
	} 
}