[自己做个游戏服务器三]你帮我为服务器选择一种加密算法，Java实现各种加解密算法

import org.apache.commons.codec.binary.Base64;
public class Aain {
    public static byte[] encode2Base64(byte[] bytes) {
        byte[] bts = Base64.encodeBase64(bytes);
        return bts;
    }
    public static byte[] decode2Base64(String str) {
        byte[] bts = Base64.decodeBase64(str);
        return bts;
    }
}
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import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
public class Aain {
    public static String md5(String str) {
        try {
            MessageDigest digest = MessageDigest.getInstance("MD5");
            return new String(digest.digest(str.getBytes()));
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return "";
    }
    public static void main(String[] args) {
        System.out.println(md5("ddddddddddddd"));;
    }
}
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计算 文件的md5值
md5sum final.nnet 
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import java.math.BigInteger;
import java.security.MessageDigest;
public class Aain {
    public static final String  KEY_SHA = "SHA";
    public static void sha(String inputStr) {
        byte[] inputData = inputStr.getBytes();
        try {
            MessageDigest messageDigest = MessageDigest.getInstance(KEY_SHA);
            messageDigest.update(inputData);
            BigInteger sha = new BigInteger(messageDigest.digest());
            System.out.println("SHA加密后:" + sha.toString(32));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    public static void main(String[] args) {
        sha("ddddddddddddd");
    }
}
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package com.xin;
import org.springframework.util.Base64Utils;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;
public class Aain {
    private static final String KEY_ALGORITHM = "AES";
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";//默认的加密算法
    /**
     * AES 加密操作
     *
     * @param content 待加密内容
     * @param key     加密密钥
     * @return 返回Base64转码后的加密数据
     */
    public static String encrypt(String content, String key) {
        try {
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);// 创建密码器
            byte[] byteContent = content.getBytes();
            cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(key));// 初始化为加密模式的密码器
            byte[] result = cipher.doFinal(byteContent);// 加密
            return Base64Utils.encodeToString(result);//通过Base64转码返回
        } catch (Exception ex) {
        }
        return null;
    }
    /**
     * AES 解密操作
     *
     * @param content
     * @param key
     * @return
     */
    public static String decrypt(String content, String key) {
        try {
            //实例化
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);
            //使用密钥初始化，设置为解密模式
            cipher.init(Cipher.DECRYPT_MODE, getSecretKey(key));
            //执行操作
            byte[] result = cipher.doFinal(Base64Utils.decodeFromString(content));
            return new String(result);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }
    /**
     * 生成加密秘钥
     *
     * @return
     */
    private static SecretKeySpec getSecretKey(final String key) {
        //返回生成指定算法密钥生成器的 KeyGenerator 对象
        KeyGenerator kg = null;
        try {
            kg = KeyGenerator.getInstance(KEY_ALGORITHM);
            //AES 要求密钥长度为 128
            kg.init(128, new SecureRandom(key.getBytes()));
            //生成一个密钥
            SecretKey secretKey = kg.generateKey();
            return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);// 转换为AES专用密钥
        } catch (NoSuchAlgorithmException ex) {
        }
        return null;
    }
    public static void main(String[] args) {
        String content = "大家好，我是香菜，公众号：香菜聊游戏";
        String key = "sde@5f98H*^hsff%dfs$r344&df8543*er";
        System.out.println("content:" + content);
        String s1 = Aain.encrypt(content, key);
        System.out.println("加密后内容 :" + s1);
        System.out.println("解密后内容:" + Aain.decrypt(s1, key));
    }
}
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