MD5加密字符串

public static String stringToMD5(String str) throws Exception

{

//定义处理后的返回值

StringBuffer result = new StringBuffer();

//定义长度为16的任意字符序列

char[] chars = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};

//将字符串转为字节数组

byte[] srcBytes = str.getBytes();

//获得MD5加密算法

MessageDigest md5 = MessageDigest.getInstance("MD5");

//用MD5加密算法对源字节数组加密

byte[] md5Bytes = md5.digest(srcBytes);

//遍历字节数组，取出高四位和低四位对应的字符,最终会得到长度为32的字符串

for(byte b:md5Bytes)

{

//处理高四位,右移4位，再与00001111，得到的结果肯定在【0-15】范围内

result.append(chars[(b >> 4) & 0x0F]);

//处理低四位，直接与00001111

result.append(chars[b & 0x0F]);

}

return result.toString();

}