工厂方法模式

加密算法：

目前常用的加密算法有DES（Data Encryption Standard）和IDEA（International Data Encryption Algorithm）国际数据加密算法等，请用工厂方法实现加密算法系统。

1. 类图：

2. Java代码：

（1）Client.java:

package test3;
import java.lang.reflect.AccessibleObject;
import java.util.Scanner;
 
 
 
public class Client {
/*
 * 去除因JDK版本造成的非法反射警告
 */
/*public static void disableWarning() {
        try {
            java.lang.reflect.Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");
            ((AccessibleObject) theUnsafe).setAccessible(true);
            Unsafe u = (Unsafe) theUnsafe.get(null);
            Class<?> cls = Class.forName("jdk.internal.module.IllegalAccessLogger");
            java.lang.reflect.Field logger = cls.getDeclaredField("logger");
            u.putObjectVolatile(cls, u.staticFieldOffset(logger), null);
        } catch (Exception e) {
        }
    }*/
 
public static void main(String[] args) {
//disableWarning();
 
        DES des = new DES();
        IDEA idea = new IDEA();
        try {
            int n = 0;
 
            @SuppressWarnings("resource")
Scanner in = new Scanner(System.in);
            while (n != 3) {
                System.out.println("请选择要使用的加密算法 1.DES加密算法 2.IDEA加密算法 3.退出");
                System.out.println("请选择：");
                if (in.hasNextInt()) {
                    n = in.nextInt();
                } else {
                    System.out.println("输入的不是整数，请重新输入：");
                    continue;
                }
                switch (n) {
                case 1: {
 
                    ((DES) des).work("1787878787878787", "0E329232EA6D0D73");
                    break;
                }
                case 2: {
                    idea.work("8787878787878787", "0E329232EA6D0D73");
                    break;
                }
                }
            }
        }catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

（2）DES.java:

package test3;
 
 
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
 
/**
 * 具体方法类DES
 * @author dell
 *
 */
public class DES implements Method{
 public void work(String str, String password) {
        String begincode = "人生苦短及时行乐"; // 要加密的明文
        String endcode = null; // 加密后的密文
        String opencode = null; // 密文解密后得到的明文
        System.out.println("要加密的明文:" + begincode);
        String cipherType = "DESede"; // 加密算法类型，可设置为DES(56)、DESede(112)、AES等字符串(128)
        try {
            // 获取密钥生成器
            KeyGenerator keyGen = KeyGenerator.getInstance(cipherType);
            // 初始化密钥生成器，不同的加密算法其密钥长度可能不同
            keyGen.init(112);
            // 生成密钥
            SecretKey key = keyGen.generateKey();
            // 得到密钥字节码
            byte[] keyByte = key.getEncoded();
            // 输出密钥的字节码
            System.out.println("密钥是：");
            for (int i = 0; i < keyByte.length; i++) {
                System.out.print(keyByte[i] + ",");
            }
            System.out.println("");
            // 创建密码器
            Cipher cp = Cipher.getInstance(cipherType);
            // 初始化密码器
            cp.init(Cipher.ENCRYPT_MODE, key);
            System.out.println("要加密的字符串是：" + begincode);
            byte[] codeStringByte = begincode.getBytes("UTF8");
            System.out.println("要加密的字符串对应的字节码是：");
            for (int i = 0; i < codeStringByte.length; i++) {
                System.out.print(codeStringByte[i] + ",");
            }
            System.out.println("");
            // 开始加密
            byte[] codeStringByteEnd = cp.doFinal(codeStringByte);
            System.out.println("加密后的字符串对应的字节码是：");
            for (int i = 0; i < codeStringByteEnd.length; i++) {
                System.out.print(codeStringByteEnd[i] + ",");
            }
            System.out.println("");
            endcode = new String(codeStringByteEnd);
            System.out.println("加密后的字符串是：" + endcode);
            System.out.println("");
            // 重新初始化密码器
            cp.init(Cipher.DECRYPT_MODE, key);
            // 开始解密
            byte[] decodeStringByteEnd = cp.doFinal(codeStringByteEnd);
            System.out.println("解密后的字符串对应的字节码是：");
            for (int i = 0; i < decodeStringByteEnd.length; i++) {
                System.out.print(decodeStringByteEnd[i] + ",");
            }
            System.out.println("");
            opencode = new String(decodeStringByteEnd);
            System.out.println("解密后的字符串是：" + opencode);
            System.out.println("");
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
 
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("DES加密算法");
        DES des = new DES();
        try {
            des.work("8787878787878787", "0E329232EA6D0D73");
 
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
}

（3）DESFactory.java:

package test3;

public class DESFactory implements MethodFactory {

    public DES produceMethod() {

        System.out.println("使用DES算法");

        return new DES();

}

}

（4）IDEA.java:

package test3;
 
 
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.jce.provider.BouncyCastleProvider;
 
 
import javax.crypto.spec.SecretKeySpec;
import java.security.Key;
import java.security.Security;
 
public class IDEA implements Method {
 
    public static final String KEY_ALGORITHM = "IDEA";
 
    public static final String CIPHER_ALGORITHM = "IDEA/ECB/ISO10126Padding";
 
    public static byte[] initkey() throws Exception {
        // 加入bouncyCastle支持
        Security.addProvider(new BouncyCastleProvider());
 
        // 实例化密钥生成器
        KeyGenerator kg = KeyGenerator.getInstance(KEY_ALGORITHM);
        // 初始化密钥生成器，IDEA要求密钥长度为128位
        kg.init(128);
        // 生成密钥
        SecretKey secretKey = kg.generateKey();
        // 获取二进制密钥编码形式
        return secretKey.getEncoded();
    }
 
    /**
     * 转换密钥
     *
     * @param key   二进制密钥       
     * @return Key 密钥
     *
     */
    private static Key toKey(byte[] key) throws Exception {
        // 实例化DES密钥
        // 生成密钥
        SecretKey secretKey = new SecretKeySpec(key, KEY_ALGORITHM);
        return secretKey;
    }
 
    /**
     * 加密数据
     *
     * @param data   待加密数据
     * @param key  密钥
     * @return byte[] 加密后的数据
     *
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 加入bouncyCastle支持
        Security.addProvider(new BouncyCastleProvider());
        // 还原密钥
        Key k = toKey(key);
        // 实例化
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        // 初始化，设置为加密模式
        cipher.init(Cipher.ENCRYPT_MODE, k);
        // 执行操作
        return cipher.doFinal(data);
    }
 
    /**
     * 解密数据
     *
     * @param data  待解密数据
     * @param key   密钥
     * @return byte[] 解密后的数据
     *
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 加入bouncyCastle支持
        Security.addProvider(new BouncyCastleProvider());
        // 还原密钥
        Key k = toKey(key);
        Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM);
        // 初始化，设置为解密模式
        cipher.init(Cipher.DECRYPT_MODE, k);
        // 执行操作
        return cipher.doFinal(data);
    }
 
    public static String getKey() {
        String result = null;
        try {
            result = Base64.encodeBase64String(initkey());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
 
    public static String ideaEncrypt(String data, String key) {
        String result = null;
        try {
            byte[] data_en = encrypt(data.getBytes(), Base64.decodeBase64(key));
            result = Base64.encodeBase64String(data_en);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
 
    public static String ideaDecrypt(String data, String key) {
        String result = null;
        try {
            byte[] data_de = decrypt(Base64.decodeBase64(data), Base64.decodeBase64(key));
            ;
            result = new String(data_de);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return result;
    }
 
    public void work(String str, String password) {
        String data = "人生苦短及时行乐"; // 要加密的明文
        String key = getKey();
        System.out.println("要加密的原文：" + data);
        System.out.println("密钥：" + key);
        String data_en = ideaEncrypt(data, key);
        System.out.println("密文：" + data_en);
        String data_de = ideaDecrypt(data_en, key);
        System.out.println("原文：" + data_de);
    }
 
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        System.out.println("IDEA加密算法");
        IDEA idea = new IDEA();
        try {
            idea.work("8787878787878787", "0E329232EA6D0D73");
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
    }
 
}

（5）IDEAFactory.java:

package test3;
 
/**
 * 具体工厂类IDEA
 * @author dell
 *
 */
public class IDEAFactory implements MethodFactory {
    public IDEA produceMethod() {
        System.out.println("使用IDEA算法");
        return new IDEA();
    }
}
（6）Method.java:
package test3;
 
/**
 * 抽象方法类
 * @author dell
 *
 */
public interface Method {
 public void work(String str, String password);
}
MethodFactory.java:
package test3;
 
 
public interface MethodFactory {
public DES produceMethod();
}
 

　　实现截图：