java自带的md5加密函数_使用java自带加密算法实现文本的md5加密算法详解

本篇使用java自带的MessageDigest实现对文本的md5加密算法，具体代码如下：

/**

[email protected]: 将字符串转化为MD5

*/

package cn.yicha.novel.util;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

public class ParseMD5 {

/**

* @param str

* @return

* @Date: 2013-9-6

* @Author: lulei

* @Description: 32位小写MD5

*/

public static String parseStrToMd5L32(String str){

String reStr = null;

try {

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

byte[] bytes = md5.digest(str.getBytes());

StringBuffer stringBuffer = new StringBuffer();

for (byte b : bytes){

int bt = b&0xff;

if (bt < 16){

stringBuffer.append(0);

}

stringBuffer.append(Integer.toHexString(bt));

}

reStr = stringBuffer.toString();

} catch (NoSuchAlgorithmException e) {

e.printStackTrace();

}

return reStr;

}

/**

* @param str

* @return

* @Date: 2013-9-6

* @Author: lulei

* @Description: 32位大写MD5

*/

public static String parseStrToMd5U32(String str){

String reStr = parseStrToMd5L32(str);

if (reStr != null){

reStr = reStr.toUpperCase();

}

return reStr;

}

/**

* @param str

* @return

* @Date: 2013-9-6

* @Author: lulei

* @Description: 16位小写MD5

*/

public static String parseStrToMd5U16(String str){

String reStr = parseStrToMd5L32(str);

if (reStr != null){

reStr = reStr.toUpperCase().substring(8, 24);

}

return reStr;

}

/**

* @param str

* @return

* @Date: 2013-9-6

* @Author: lulei

* @Description: 16位大写MD5

*/

public static String parseStrToMd5L16(String str){

String reStr = parseStrToMd5L32(str);

if (reStr != null){

reStr = reStr.substring(8, 24);

}

return reStr;

}

}