java md5 32位小写

以下是Java实现MD5 32位小写加密的代码示例：

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

public class MD5Example {
    public static void main(String[] args) {
        String str = "Hello World";
        String md5code = md5(str);
        System.out.println("MD5 value: " + md5code);
    }

    public static String md5(String str) {
        byte[] secretBytes = null;
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(str.getBytes());
            secretBytes = md.digest();
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("No such algorithm: MD5");
        }

        BigInteger bigInt = new BigInteger(1, secretBytes);
        String md5code = bigInt.toString(16);
        while (md5code.length() < 32) {
            md5code = "0" + md5code;
        }
        return md5code;
    }
}