import java.security.MessageDigest;
public class MD5_tes {

public final static String MD5(String s){
char hexDigits[]={'0','1','2','3','4','5','6','7',
'8','9','a','b','c','d','e','f'};
try{
byte[] strTemp = s.getBytes();
MessageDigest mdTemp = MessageDigest.getInstance("MD5");
mdTemp.update(strTemp);
byte[] md=mdTemp.digest();
int j= md.length;
char str[]=new char[j*2];
int k=0;
for(int i=0;i<j;i++){
byte byte0=md[i];
str[k++] = hexDigits[byte0 >>> 4 & 0xf];
str[k++] = hexDigits[byte0 & 0xf];
}
return new String(str);
}catch(Exception e){
return null;
}

}

public static void main(String[] args){
System.out.println(MD5_tes.MD5("b"));
}
}

运行该Java代码，输出“b” MD5加密后的结果32位：

92eb5ffee6ae2fec3ad71c777531578f