import java.security.MessageDigest;
import sun.misc.BASE64Encoder;
public class MD5Util {
/**
*
* @param pwd
* 需要加密的字符串
* @param type
* 字母大小寫(false爲默認小寫,true爲大寫)
* @param bit
* 加密的類型(16,32,64)
* @return
*/
public static String getMD5(String pwd, boolean isUpper, Integer bit) {
String md5 = new String();
try {
// 創建加密對象
MessageDigest md = MessageDigest.getInstance("md5");
if (bit == 64) {
BASE64Encoder bw = new BASE64Encoder();
String bsB64 = bw.encode(md.digest(pwd.getBytes("utf-8")));
md5 = bsB64;
} else {
// 計算MD5函數
md.update(pwd.getBytes());
byte b[] = md.digest();
int i;
StringBuffer sb = new StringBuffer("");
for (int offset = 0; offset < b.length; offset++) {
i = b[offset];
if (i < 0)
i += 256;
if (i < 16)
sb.append("0");
sb.append(Integer.toHexString(i));
}
md5 = sb.toString();
if(bit == 16) {
//截取32位md5爲16位
String md16 = md5.substring(8, 24).toString();
md5 = md16;
if (isUpper)
md5 = md5.toUpperCase();
return md5;
}
}
//轉換成大寫
if (isUpper)
md5 = md5.toUpperCase();
} catch (Exception e) {
e.printStackTrace();
System.out.println("md5加密拋出異常!");
}
return md5;
}
public static void main(String[] args) throws Exception {
String a = "123";
String md5a = getMD5(a, true, 16);
System.out.println(md5a);
System.out.println(md5a.length());
}
}
運行結果: