MD5加密工具类MD5Utils

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Utils {
/**
* 使用md5的算法进行加密
*/
public static String md5(String plainText) {
byte[] secretBytes = null;
try {
secretBytes = MessageDigest.getInstance("md5").digest(
plainText.getBytes());
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException("没有md5这个算法！");
}
String md5code = new BigInteger(1, secretBytes).toString(16);// 16进制数字
// 如果生成数字未满32位，需要前面补0
for (int i = 0; i < 32 - md5code.length(); i++) {
md5code = "0" + md5code;
}
return md5code;
}


public static void main(String[] args) {
System.out.println(md5("1234"));
}
}