package test
;
import java.security.MessageDigest
;
/**
* Created by LDX on 2018/4/4.
*/
public class MD5 {
public static String
bytesToHexString(
byte[] src) {
StringBuilder stringBuilder =
new StringBuilder(
"")
;
if (src ==
null || src.
length <=
0) {
return null;
}
for (
int i =
0; i < src.
length; i++) {
int v = src[i] &
0xFF;
String hv = Integer.
toHexString(v)
;
if (hv.length() <
2) {
stringBuilder.append(
0)
;
}
stringBuilder.append(hv)
;
}
return stringBuilder.toString()
;
}
/**
* 解析
*
* @param hexString
* @return
*/
public static byte[]
hexStringToBytes(String hexString) {
if (hexString ==
null || hexString.equals(
"")) {
return null;
}
hexString = hexString.toUpperCase()
;
int length = hexString.length() /
2;
char[] hexChars = hexString.toCharArray()
;
byte[] d =
new byte[length]
;
for (
int i =
0; i < length
; i++) {
int pos = i *
2;
d[i] = (
byte) (
charToByte(hexChars[pos]) <<
4 |
charToByte(hexChars[pos +
1]))
;
}
return d
;
}
/**
* 将指定byte数组以16进制的形式打印到控制台
*
* @param b
*/
public static void printHexString(
byte[] b) {
for (
int i =
0; i < b.
length; i++) {
String hex = Integer.
toHexString(b[i] &
0xFF)
;
if (hex.length() ==
1) {
hex =
'0' + hex
;
}
System.
out.print(hex.toUpperCase())
;
}
}
/**
* Convert char to byte
*
* @param c char
* @return byte
*/
private static byte charToByte(
char c) {
return (
byte)
"0123456789abcdef".indexOf(c)
;
}
/**
* 加密
*
* @param str
* @return
*/
public static String
encode(String str) {
String strDigest =
"";
try {
// 此 MessageDigest 类为应用程序提供信息摘要算法的功能，必须用try,catch捕获
MessageDigest md5 = MessageDigest.
getInstance(
"MD5")
;
byte[] data
;
data = md5.digest(str.getBytes(
"utf-8"))
;// 转换为MD5码
strDigest =
bytesToHexString(data)
;
}
catch (Exception ex) {
throw new RuntimeException(ex)
;
}
return strDigest
;
}
}
