java实现MD5加密

1 加密方法：

1.1 java自带jar工具MessageDigest实现
java.security.MessageDigest

public class MD5Utils {    public static String stringToMD5(String plainText) {        byte[] secretBytes = null;        try {            secretBytes = MessageDigest.getInstance("md5").digest(                    plainText.getBytes());        } catch (NoSuchAlgorithmException e) {            throw new RuntimeException("没有这个md5算法！");        }        String md5code = new BigInteger(1, secretBytes).toString(16);        for (int i = 0; i < 32 - md5code.length(); i++) {            md5code = "0" + md5code;        }        return md5code;    }}

1.2 spring自带的工具DigestUtils实现
org.springframework.util.DigestUtils

DigestUtils.md5DigestAsHex("1234".getBytes())

2 使用方法：

@Testpublic void testMd5() throws NoSuchAlgorithmException{    MessageDigest md = MessageDigest.getInstance("MD5");    // java自带工具包MessageDigest      String resultString = MD5Utils.md5("123456");    System.out.println(resultString);    // e10adc3949ba59abbe56e057f20f883e    String resultString1 = MD5Utils.md5("1234");    System.out.println(resultString1);    //81dc9bdb52d04dc20036dbd8313ed055    // spring自带工具包DigestUtils    System.out.println(DigestUtils.md5DigestAsHex("1234".getBytes()));    // 81dc9bdb52d04dc20036dbd8313ed055}