关于proxy

╰半橙微兮° 2022-04-04 06:26 172阅读 0赞

那Java怎么跟代理勾搭上？代理能帮我们做什么？有哪些实践？

代理其实在程序语言中来源于设计模式：代理模式------使用代理对象完成用户请求，屏蔽了用户对真实对象的访问。就像租房子：房东拥有房屋，对房子有控制权，可以将使用权转让。我作为租客需要验证房东是不是有房权证啊 具不具备出租资格啊。验证完了之后要定租金 签订合同啊。房东只是想把房子出租出去，不想关注怎么验证，怎么拟合同，太麻烦了，也不专业。这时候就需要代理出面了。

房东：我要出租房子！

中介：我要验证信息 签订合同 定期收房租！

我：租房子！

各司其职，单一职责 整个世界清晰了。 让我们来实现吧……

接口：可以出租房子的人

public interface Owner {
    /**
         * 将房屋出租给租客
         * @param tenantName
         * @return
         */
        Boolean rentHouse(String tenantName);
    
        /**
         * 返回房东姓名
         * @return
         */
        String findHouseOwnerName();
    
    }

房东实现了Owner接口：

public class HouseOwner implements Owner {
    
    private String ownerName;
    
        public HouseOwner(String ownerName) {
    this.ownerName = ownerName;
        }
    
    public Boolean rentHouse(String tenantName) {
    //房东只愿意把房子租给叫vincent的人 就是我拉
            if (StringUtils.equalsIgnoreCase("vincent", tenantName))         {
                System.out.println(StringUtils.join(ownerName + "愿意将房子出租给" + tenantName));
                return Boolean.TRUE;
            } else {
                System.out.println(StringUtils.join(ownerName + "拒绝将房子出租给" + tenantName));
            }
    return Boolean.FALSE;
        }
    
    public String findHouseOwnerName() {
    return ownerName;
        }
    }
    中介：中介也实现了Owner接口 但他只是代理
    
    public class HouseOwnerProxy implements Owner {
    
    private Owner houseOwner;
    
        public HouseOwnerProxy(Owner houseOwner) {
    this.houseOwner = houseOwner;
        }
    
    public Boolean rentHouse(String tenantName) {
            System.out.println("第一步：检查房东房屋的合法性");
            Boolean isSuccessRent = houseOwner.rentHouse(tenantName);
            if (isSuccessRent) {
                System.out.println(StringUtils.join("第二步：与", tenantName, "签订租房合同"));
                System.out.println("最后一步：将信息同步给房东" + houseOwner.findHouseOwnerName() + "，完成分成！！！");
            } else {
                System.out.println("房东拒绝出租，看下一家……");
            }
    return isSuccessRent;
        }
    
    public String findHouseOwnerName() {
    return houseOwner.findHouseOwnerName();
        }
    }

租房场景：

public class ProxyTestCenter {
    public static void main(String[] args) {
    //房东
            HouseOwner houseOwner = new HouseOwner("包租婆");
            //中介
            HouseOwnerProxy proxy = new HouseOwnerProxy(houseOwner);
            //中介出租房屋给vincent
            proxy.rentHouse("vincent");
        }
    }

运行结果：

整个流程就是这样呢 。虽说是中介出租房屋给我 其实真正的幕后是房东在处理。  
上面就是【静态代理】。

HouseOwnerProxy也像HouseOwner一样实现了Owner接口，但实际调用的是HouseOwner的实现。它在调用的前后加上了其他的功能 ：检查房屋的合法性 签订合同 房租等…… 比较装逼的叫法是：无入侵的类代理！！

刚才是代理类为我们处理了额外的事情：检查合法性，制定合同等；房东只关心他自己的部分。我们可以联想代理可以为我们做什么？sample：假如我们需要监控每个业务service方法的处理时间以实现对慢处理的优化【类似DB慢查询log】，该怎么做？

—我们在方法开始记录一个时间 在方法处理完后记录时间 两个时间相减即可。

这样我们需要对我们2000多个service差不多60000个方法都加上这样的代码，这样监控的代码和业务实现的代码耦合在一起，像一坨屎一样！我们要分开，所以我们写了2000个代理类60000个代理方法，这样分开了！找了个实习生终于写完了，，第二天code review的时候 实习生背了锅 被开了。架构师对我说 ：“vincent 你负责把他的静态代理改成动态的。” 我答应了，尽管我并不知道什么叫“动态代理”。

为了能够逆袭追 . 上女神，一代码农vincent开始熬夜查资料，终于研究明白了。他打算在下一个分享日给大家分享----JDK动态代理。

“动态代理” ------- 动态地生成代理类！ 让我们忘了那个一个一个方法手写代理类的实习生吧，动态生成吧。vincent改了代码，他了解到JDK内置的动态代理核心就是两个类(接口)。InvocationHandler 和 Proxy！ InvocationHandler翻译过来叫调用处理器，是一个接口，有一个需要实现的方法

public Object invoke(Object proxy, Method method, Object[] args)
    throws Throwable;
    proxy就是动态代理类，我们用动态代理来实现业务吧:
    
    public interface Owner {
    
        Boolean rentHouse(String tenantName) throws InterruptedException;
    
        void cleanHouse() throws InterruptedException;
    
        void decorateHouse() throws InterruptedException;
    
        void sleepWithGirls() throws InterruptedException;
    
    }
    public class HouseOwner implements Owner {
    
    private String ownerName;
    
        public HouseOwner(String ownerName) {
    this.ownerName = ownerName;
        }
    
    public Boolean rentHouse(String tenantName) throws InterruptedException {
            TimeUnit.SECONDS.sleep(RandomUtils.nextInt(5));
            return Boolean.TRUE;
        }
    
    public void cleanHouse() throws InterruptedException {
            TimeUnit.SECONDS.sleep(RandomUtils.nextInt(5));
        }
    
    public void decorateHouse() throws InterruptedException {
            TimeUnit.SECONDS.sleep(RandomUtils.nextInt(5));
        }
    
    public void sleepWithGirls() throws InterruptedException {
            TimeUnit.SECONDS.sleep(RandomUtils.nextInt(5));
        }
    
    public String findHouseOwnerName() {
    return ownerName;
        }
    }

注意下面的代理类，实现了InvocationHandler接口，不再一一实现每一个方法了！！！

public class HouseOwnerProxy implements InvocationHandler {
    
    private Owner houseOwner;
    
        public HouseOwnerProxy(Owner houseOwner) {
    this.houseOwner = houseOwner;
        }
    
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
    long startTime = System.currentTimeMillis();
            Object result = method.invoke(houseOwner, args);
            long endTime = System.currentTimeMillis();
            System.out.println(StringUtils.join( method.getName() + "方法一共消耗了：", endTime - startTime) + "  毫秒");
            return result;
        }
    
    public Owner  getOwnerProxy(){
    return (Owner)     Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(),
           houseOwner.getClass().getInterfaces(),this);
        }
    }

下面是具体场景：

public class ProxyTestCenter {
    public static void main(String[] args) throws InterruptedException {
    //房东
            HouseOwner houseOwner = new HouseOwner("包租婆");
            //中介
            HouseOwnerProxy proxy = new HouseOwnerProxy(houseOwner);
            //生产代理类
            Owner owner = proxy.getOwnerProxy();
    
            owner.cleanHouse();
            owner.decorateHouse();
            owner.rentHouse("vincent");
            owner.sleepWithGirls();
        }
    }

中介通过InvocationHandler代理了【每一个方法】，运行结果：

这样我们就动态地实现代理，之所以叫“动态”，是getOwnerProxy这里：

(Owner) Proxy.newProxyInstance(
    Thread.currentThread().getContextClassLoader(),
    houseOwner.getClass().getInterfaces(),
    this)

创建了具体的实现，让我们分析下这个方法的参数，第一个是ClassLoader，第二个是被代理类实现的接口们 ，第三个是代理类。我们猜想，jvm在运行的时候是【动态创建了具有那些接口属性，并加上代理实现】的类，然后调用代理类的 cleanHouse， decorateHouse的方法。

静态代理从代码层面很容易理解，而动态代理总让人觉得有点悬乎，到底发生了什么？为什么按照这样的方式就能代理每一个方法？没办法，看源码喽……

public interface InvocationHandler {
    
    public Object invoke(Object proxy, Method method, Object[] args)
    throws Throwable;
    }
    InvocationHandler就是一个接口而已，看来就是一颗棋子，没什么料。剩下的就是Proxy类了，由Proxy.newProxyInstance开始吧：
    
    public static Object newProxyInstance(ClassLoader loader,
                                          Class<?>[] interfaces,
                                          InvocationHandler h)
    throws IllegalArgumentException
    {
      
    if (h == null) {
    throw new NullPointerException();
        }
     //获取接口类
    final Class<?>[] intfs = interfaces.clone();
    //安全检查 跳过
        final SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
    checkProxyAccess(Reflection.getCallerClass(), loader, intfs);
        }
    
    /*
         * Look up or generate the designated proxy class.
         */
    //重点就在这了  如何获取的Class？？？？？
        Class<?> cl = getProxyClass0(loader, intfs);
    
        /*
         * Invoke its constructor with the designated invocation handler.
         */
    //以下可以看作是通过反射 生成对象 
        try {
    final Constructor<?> cons = cl.getConstructor(constructorParams);
            final InvocationHandler ih = h;
            if (sm != null && ProxyAccessHelper.needsNewInstanceCheck(cl)) {
    // create proxy instance with doPrivilege as the proxy class may
                // implement non-public interfaces that requires a special permission
                return AccessController.doPrivileged(new PrivilegedAction<Object>() {
    public Object run() {
    return newInstance(cons, ih);
                    }
                });
            } else {
    return newInstance(cons, ih);
            }
        } catch (NoSuchMethodException e) {
    throw new InternalError(e.toString());
        }
    }

由上面单拿出来：`Class<?> cl = getProxyClass0(loader, intfs);`

进去：

private static Class<?> getProxyClass0(ClassLoader loader,
                                           Class<?>... interfaces) {
    if (interfaces.length > 65535) {
    throw new IllegalArgumentException("interface limit exceeded");
        }
         //看着应该是自己做的map cache
        return proxyClassCache.get(loader, interfaces);
    }
    显然proxyClassCache.get 进去：
    
    proxyClassCache.get(loader, interfaces);
    public V get(K key, P parameter) {
        Objects.requireNonNull(parameter);
    
        expungeStaleEntries();
    
        Object cacheKey = CacheKey.valueOf(key, refQueue);
    
        // lazily install the 2nd level valuesMap for the particular cacheKey
        ConcurrentMap<Object, Supplier<V>> valuesMap = map.get(cacheKey);
        if (valuesMap == null) {
            ConcurrentMap<Object, Supplier<V>> oldValuesMap
                = map.putIfAbsent(cacheKey,
                                  valuesMap = new ConcurrentHashMap<>());
            if (oldValuesMap != null) {
                valuesMap = oldValuesMap;
            }
        }
    
    // create subKey and retrieve the possible Supplier<V> stored by that
        // subKey from valuesMap
        Object subKey = Objects.requireNonNull(subKeyFactory.apply(key, parameter));
        Supplier<V> supplier = valuesMap.get(subKey);
        Factory factory = null;
    
        while (true) {
    if (supplier != null) {
    // supplier might be a Factory or a CacheValue<V> instance
                V value = supplier.get();
                if (value != null) {
    return value;
                }
            }
    // else no supplier in cache
            // or a supplier that returned null (could be a cleared CacheValue
            // or a Factory that wasn't successful in installing the CacheValue)
    
            // lazily construct a Factory
            if (factory == null) {
                factory = new Factory(key, parameter, subKey, valuesMap);
            }
    
    if (supplier == null) {
                supplier = valuesMap.putIfAbsent(subKey, factory);
                if (supplier == null) {
    // successfully installed Factory
                    supplier = factory;
                }
    // else retry with winning supplier
            } else {
    if (valuesMap.replace(subKey, supplier, factory)) {
    // successfully replaced
                    // cleared CacheEntry / unsuccessful Factory
                    // with our Factory
                    supplier = factory;
                } else {
    // retry with current supplier
                    supplier = valuesMap.get(subKey);
                }
            }
        }
    }
    不再赘述，找到Object subKey = Objects.requireNonNull(subKeyFactory.apply(key, parameter));

进去（看源码重要的不是看什么 而是不看什么！）：

public Class<?> apply(ClassLoader loader, Class<?>[] interfaces) {
        
             //掉过  直奔主题
            /*
             * Generate the specified proxy class.
             */
            byte[] proxyClassFile = ProxyGenerator.generateProxyClass(
                proxyName, interfaces);
        
        return defineClass0(loader, proxyName,
                                    proxyClassFile, 0, proxyClassFile.length);
        
        }
    
    由上面进入：ProxyGenerator.generateProxyClass( proxyName, interfaces)
    
    //看名字是多么的直白啊 
    public static byte[] generateProxyClass(final String var0, Class[] var1) {
        ProxyGenerator var2 = new ProxyGenerator(var0, var1);
    //通过var2来创建类的字节码 核心实现 有很多的字节操作细节
        final byte[] var3 = var2.generateClassFile();
    //  saveGeneratedFiles参数是new GetBooleanAction("sun.misc.ProxyGenerator.saveGeneratedFiles"))).booleanValue();  如果为true 创建class到文件系统
      
        if(saveGeneratedFiles) {
            AccessController.doPrivileged(new PrivilegedAction() {
    public Void run() {
    try {
    int var1 = var0.lastIndexOf(46);
                        Path var2;
                        if(var1 > 0) {
                            Path var3x = Paths.get(var0.substring(0, var1).replace('.', File.separatorChar), new String[0]);
                            Files.createDirectories(var3x, new FileAttribute[0]);
                            var2 = var3x.resolve(var0.substring(var1 + 1, var0.length()) + ".class");
                        } else {
                            var2 = Paths.get(var0 + ".class", new String[0]);
                        }
    
                        Files.write(var2, var3, new OpenOption[0]);
                        return null;
                    } catch (IOException var4) {
    throw new InternalError("I/O exception saving generated file: " + var4);
                    }
                }
            });
        }
    
    return var3;
    }

generateProxyClass还能更明显么？终于找到你。我们通过sun.misc.ProxyGenerator.saveGeneratedFiles能找到class文件，OK ，我就想找到动态生成的class文件看一眼，通过代码很难分析到底生成到那个路径了，只能debug了，我就debug刚才的main方法，万万没想到：

默认的值是false。也就是生成的class不落盘，那咋办？刚才我们知道：

saveGeneratedFiles = ((Boolean)AccessController.doPrivileged(new GetBooleanAction("sun.misc.ProxyGenerator.saveGeneratedFiles"))).booleanValue();

哈. 一个参数而已，我们自己重新设置，所以有了：

public class FuckProxyGenerator {
    
    private static final String SAVEGENERATEDFLAG = "sun.misc.ProxyGenerator.saveGeneratedFiles";
    
    public static void generatorClass() throws IOException {
        Boolean systemParam = Boolean.valueOf(System.getProperty(SAVEGENERATEDFLAG));
        if (Boolean.FALSE == systemParam) {
            System.setProperty(SAVEGENERATEDFLAG, Boolean.TRUE.toString());
        }
        systemParam = Boolean.valueOf(System.getProperty(SAVEGENERATEDFLAG));
        byte[] byteArray = ProxyGenerator.generateProxyClass("ProxyClass", HouseOwner.class.getInterfaces());
        FileUtils.writeByteArrayToFile(new File("/Users/vincent/Documents/tempFiles/TargetHouseOwnerProxy.class"), byteArray);
    
    }
    
    public static void main(String[] args) throws IOException {
    generatorClass();
        }
    
    }
    反编译TargetHouseOwnerProxy.class
    
    import com.starbucks.demo.proxy.Owner;
    import java.lang.reflect.InvocationHandler;
    import java.lang.reflect.Method;
    import java.lang.reflect.Proxy;
    import java.lang.reflect.UndeclaredThrowableException;
    
    public final class ProxyClass extends Proxy
    implements Owner
    {
    private static Method m3;
        private static Method m1;
        private static Method m6;
        private static Method m4;
        private static Method m0;
        private static Method m5;
        private static Method m2;
    
        public ProxyClass(InvocationHandler paramInvocationHandler)
    throws
        {
    super(paramInvocationHandler);
        }
    
    public final Boolean rentHouse(String paramString)
    throws InterruptedException
        {
    try
            {
    return (Boolean)this.h.invoke(this, m3, new Object[] { paramString });
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final boolean equals(Object paramObject)
    throws
        {
    try
            {
    return ((Boolean)this.h.invoke(this, m1, new Object[] { paramObject })).booleanValue();
            }
    catch (Error|RuntimeException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final void sleepWithGirls()
    throws InterruptedException
        {
    try
            {
    this.h.invoke(this, m6, null);
                return;
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final void cleanHouse()
    throws InterruptedException
        {
    try
            {
    this.h.invoke(this, m4, null);
                return;
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final int hashCode()
    throws
        {
    try
            {
    return ((Integer)this.h.invoke(this, m0, null)).intValue();
            }
    catch (Error|RuntimeException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final void decorateHouse()
    throws InterruptedException
        {
    try
            {
    this.h.invoke(this, m5, null);
                return;
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final String toString()
    throws
        {
    try
            {
    return (String)this.h.invoke(this, m2, null);
            }
    catch (Error|RuntimeException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    static
        {
    try
            {
    m3 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("rentHouse", new Class[] { Class.forName("java.lang.String") });
                m1 = Class.forName("java.lang.Object").getMethod("equals", new Class[] { Class.forName("java.lang.Object") });
                m6 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("sleepWithGirls", new Class[0]);
                m4 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("cleanHouse", new Class[0]);
                m0 = Class.forName("java.lang.Object").getMethod("hashCode", new Class[0]);
                m5 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("decorateHouse", new Class[0]);
                m2 = Class.forName("java.lang.Object").getMethod("toString", new Class[0]);
                return;
            }
    catch (NoSuchMethodException localNoSuchMethodException)
            {
    throw new NoSuchMethodError(localNoSuchMethodException.getMessage());
            }
    catch (ClassNotFoundException localClassNotFoundException)
            {
    throw new NoClassDefFoundError(localClassNotFoundException.getMessage());
            }
        }
    }import com.starbucks.demo.proxy.Owner;
            import java.lang.reflect.InvocationHandler;
            import java.lang.reflect.Method;
            import java.lang.reflect.Proxy;
            import java.lang.reflect.UndeclaredThrowableException;
    
    public final class ProxyClass extends Proxy
    implements Owner
    {
    private static Method m3;
        private static Method m1;
        private static Method m6;
        private static Method m4;
        private static Method m0;
        private static Method m5;
        private static Method m2;
    
        public ProxyClass(InvocationHandler paramInvocationHandler)
    throws
        {
    super(paramInvocationHandler);
        }
    
    public final Boolean rentHouse(String paramString)
    throws InterruptedException
        {
    try
            {
    return (Boolean)this.h.invoke(this, m3, new Object[] { paramString });
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final boolean equals(Object paramObject)
    throws
        {
    try
            {
    return ((Boolean)this.h.invoke(this, m1, new Object[] { paramObject })).booleanValue();
            }
    catch (Error|RuntimeException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final void sleepWithGirls()
    throws InterruptedException
        {
    try
            {
    this.h.invoke(this, m6, null);
                return;
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final void cleanHouse()
    throws InterruptedException
        {
    try
            {
    this.h.invoke(this, m4, null);
                return;
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final int hashCode()
    throws
        {
    try
            {
    return ((Integer)this.h.invoke(this, m0, null)).intValue();
            }
    catch (Error|RuntimeException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final void decorateHouse()
    throws InterruptedException
        {
    try
            {
    this.h.invoke(this, m5, null);
                return;
            }
    catch (Error|RuntimeException|InterruptedException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    public final String toString()
    throws
        {
    try
            {
    return (String)this.h.invoke(this, m2, null);
            }
    catch (Error|RuntimeException localError)
            {
    throw localError;
            }
    catch (Throwable localThrowable)
            {
    throw new UndeclaredThrowableException(localThrowable);
            }
        }
    
    static
        {
    try
            {
    m3 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("rentHouse", new Class[] { Class.forName("java.lang.String") });
                m1 = Class.forName("java.lang.Object").getMethod("equals", new Class[] { Class.forName("java.lang.Object") });
                m6 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("sleepWithGirls", new Class[0]);
                m4 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("cleanHouse", new Class[0]);
                m0 = Class.forName("java.lang.Object").getMethod("hashCode", new Class[0]);
                m5 = Class.forName("com.starbucks.demo.proxy.Owner").getMethod("decorateHouse", new Class[0]);
                m2 = Class.forName("java.lang.Object").getMethod("toString", new Class[0]);
                return;
            }
    catch (NoSuchMethodException localNoSuchMethodException)
            {
    throw new NoSuchMethodError(localNoSuchMethodException.getMessage());
            }
    catch (ClassNotFoundException localClassNotFoundException)
            {
    throw new NoClassDefFoundError(localClassNotFoundException.getMessage());
            }
        }
    }

其中

public final class ProxyClass extends Proxy implements Owner

就是动态生成的代理类。

抽出一个方法看一下：

Boolean rentHouse(String paramString)
    
    return (Boolean)this.h.invoke(this, m3, new Object[] { paramString });

就是调用了实现InvocationHandler接口的代理类中得invoke方法。

public ProxyClass(InvocationHandler paramInvocationHandler) throws {
    super(paramInvocationHandler);
    }

也就是说：动态代理是jvm运行时会动态创建一个代理类 实现其中每一个方法。在调用时实际是调用那个代理类的方法而已。是动态的生成静态代理类！

这样貌似明白了动态代理，开始用动态代理替代静态的代理----那2000个service的运行时间监控。又一轮的code review，架构师看了vincent的代码，说“vincent，你可以用CGLib啊！再优化优化，太业余了” vincent卒 享年25岁！