Cglib 與 JDK動態代理的運行性能比較

時間  2019-11-21
標籤 cglib jdk 動態 代理 運行 性能 比較 欄目 Java 简体版
原文   原文鏈接

都說 Cglib 建立的動態代理的運行性能比 JDK 動態代理能高出大概 10 倍，今日抱着懷疑精神驗證了一下，發現狀況有所不一樣，遂貼出實驗結果，以供參考和討論。java

代碼很簡單，首先，定義一個 Test 接口，和一個實現 TestImpl 。Test 接口僅定義一個方法 test，對傳入的 int 參數加 1 後返回。代碼以下：性能

package my.test;

public interface Test {
    
    public int test(int i);
    
}

 

package my.test;

public class TestImpl implements Test{
    public int test(int i) {
        return i+1;
    }
}

 

 

而後，定義了三種代理的實現：裝飾者模式實現的代理(decorator)，JDK 動態代理(dynamic proxy) 和 Cglib 動態代理 (cglib proxy)。代碼以下：測試

package my.test;

public class DecoratorTest implements Test{
    private Test target;
    
    public DecoratorTest(Test target) {
        this.target = target;
    }

    public int test(int i) {
        return target.test(i);
    }
}

 

package my.test;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

public class DynamicProxyTest implements InvocationHandler {
    private Test target;

    private DynamicProxyTest(Test target) {
        this.target = target;
    }

    public static Test newProxyInstance(Test target) {
        return (Test) Proxy
                .newProxyInstance(DynamicProxyTest.class.getClassLoader(),
                        new Class<?>[] { Test.class },
                        new DynamicProxyTest(target));

    }

    public Object invoke(Object proxy, Method method, Object[] args)
            throws Throwable {
        return method.invoke(target, args);
    }
}
package my.test;

import java.lang.reflect.Method;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

public class CglibProxyTest implements MethodInterceptor {
    
    private CglibProxyTest() {
    }
    
    public static <T extends Test> Test newProxyInstance(Class<T> targetInstanceClazz){
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(targetInstanceClazz);
        enhancer.setCallback(new CglibProxyTest());
        return (Test) enhancer.create();
    }

    public Object intercept(Object obj, Method method, Object[] args,
            MethodProxy proxy) throws Throwable {
        return proxy.invokeSuper(obj, args);
    }

}

 

 

以 TestImpl 的調用耗時做爲基準，對比經過其它三種代理進行調用的耗時。測試代碼以下：this

package my.test;

import java.util.LinkedHashMap;
import java.util.Map;

public class ProxyPerfTester {

    public static void main(String[] args) {
        //建立測試對象；
        Test nativeTest = new TestImpl();
        Test decorator = new DecoratorTest(nativeTest);
        Test dynamicProxy = DynamicProxyTest.newProxyInstance(nativeTest);
        Test cglibProxy = CglibProxyTest.newProxyInstance(TestImpl.class);

        //預熱一下；
        int preRunCount = 10000;
        runWithoutMonitor(nativeTest, preRunCount);
        runWithoutMonitor(decorator, preRunCount);
        runWithoutMonitor(cglibProxy, preRunCount);
        runWithoutMonitor(dynamicProxy, preRunCount);
        
        //執行測試；
        Map<String, Test> tests = new LinkedHashMap<String, Test>();
        tests.put("Native   ", nativeTest);
        tests.put("Decorator", decorator);
        tests.put("Dynamic  ", dynamicProxy);
        tests.put("Cglib    ", cglibProxy);
        int repeatCount = 3;
        int runCount = 1000000;
        runTest(repeatCount, runCount, tests);
        runCount = 50000000;
        runTest(repeatCount, runCount, tests);
    }
    
    private static void runTest(int repeatCount, int runCount, Map<String, Test> tests){
        System.out.println(String.format("\n==================== run test : [repeatCount=%s] [runCount=%s] [java.version=%s] ====================", repeatCount, runCount, System.getProperty("java.version")));
        for (int i = 0; i < repeatCount; i++) {
            System.out.println(String.format("\n--------- test : [%s] ---------", (i+1)));
            for (String key : tests.keySet()) {
                runWithMonitor(tests.get(key), runCount, key);
            }
        }
    }
    
    private static void runWithoutMonitor(Test test, int runCount) {
        for (int i = 0; i < runCount; i++) {
            test.test(i);
        }
    }
    
    private static void runWithMonitor(Test test, int runCount, String tag) {
        long start = System.currentTimeMillis();
        for (int i = 0; i < runCount; i++) {
            test.test(i);
        }
        long end = System.currentTimeMillis();
        System.out.println("["+tag + "] Elapsed Time:" + (end-start) + "ms");
    }
}

 

 

測試用例分別在 jdk六、 jdk七、jdk8 下進行了測試，每次測試分別以 1,000,000 和 50,000,000 循環次數調用 test 方法，並重復3次。spa

  • jdk6 下的測試結果以下：
==================== run test : [repeatCount=3] [runCount=1000000] [java.version=1.6.0_45] ====================

--------- test : [1] ---------
[Native   ] Elapsed Time:2ms
[Decorator] Elapsed Time:12ms
[Dynamic  ] Elapsed Time:31ms
[Cglib    ] Elapsed Time:31ms

--------- test : [2] ---------
[Native   ] Elapsed Time:7ms
[Decorator] Elapsed Time:7ms
[Dynamic  ] Elapsed Time:31ms
[Cglib    ] Elapsed Time:27ms

--------- test : [3] ---------
[Native   ] Elapsed Time:7ms
[Decorator] Elapsed Time:6ms
[Dynamic  ] Elapsed Time:23ms
[Cglib    ] Elapsed Time:29ms

==================== run test : [repeatCount=3] [runCount=50000000] [java.version=1.6.0_45] ====================

--------- test : [1] ---------
[Native   ] Elapsed Time:212ms
[Decorator] Elapsed Time:226ms
[Dynamic  ] Elapsed Time:1054ms
[Cglib    ] Elapsed Time:830ms

--------- test : [2] ---------
[Native   ] Elapsed Time:184ms
[Decorator] Elapsed Time:222ms
[Dynamic  ] Elapsed Time:1020ms
[Cglib    ] Elapsed Time:826ms

--------- test : [3] ---------
[Native   ] Elapsed Time:184ms
[Decorator] Elapsed Time:208ms
[Dynamic  ] Elapsed Time:979ms
[Cglib    ] Elapsed Time:832ms

 

　　測試結果代表：jdk6 下，在運行次數較少的狀況下，jdk動態代理與 cglib 差距不明顯，甚至更快一些；而當調用次數增長以後， cglib 表現稍微更快一些，然而僅僅是「稍微」好一些，遠沒達到 10 倍差距。代理

  • jdk7 下的測試結果以下：
==================== run test : [repeatCount=3] [runCount=1000000] [java.version=1.7.0_60] ====================

--------- test : [1] ---------
[Native   ] Elapsed Time:2ms
[Decorator] Elapsed Time:12ms
[Dynamic  ] Elapsed Time:19ms
[Cglib    ] Elapsed Time:26ms

--------- test : [2] ---------
[Native   ] Elapsed Time:3ms
[Decorator] Elapsed Time:5ms
[Dynamic  ] Elapsed Time:17ms
[Cglib    ] Elapsed Time:20ms

--------- test : [3] ---------
[Native   ] Elapsed Time:4ms
[Decorator] Elapsed Time:4ms
[Dynamic  ] Elapsed Time:13ms
[Cglib    ] Elapsed Time:27ms

==================== run test : [repeatCount=3] [runCount=50000000] [java.version=1.7.0_60] ====================

--------- test : [1] ---------
[Native   ] Elapsed Time:208ms
[Decorator] Elapsed Time:210ms
[Dynamic  ] Elapsed Time:551ms
[Cglib    ] Elapsed Time:923ms

--------- test : [2] ---------
[Native   ] Elapsed Time:238ms
[Decorator] Elapsed Time:210ms
[Dynamic  ] Elapsed Time:483ms
[Cglib    ] Elapsed Time:872ms

--------- test : [3] ---------
[Native   ] Elapsed Time:217ms
[Decorator] Elapsed Time:208ms
[Dynamic  ] Elapsed Time:494ms
[Cglib    ] Elapsed Time:881ms

 

測試結果代表：jdk7 下，狀況發生了逆轉！在運行次數較少（1,000,000）的狀況下，jdk動態代理比 cglib 快了差很少30%；而當調用次數增長以後(50,000,000)， 動態代理比 cglib 快了接近1倍。code

接下來再看看jdk8下的表現如何。orm

  • jdk8 下的測試結果以下：
==================== run test : [repeatCount=3] [runCount=1000000] [java.version=1.8.0_05] ====================

--------- test : [1] ---------
[Native   ] Elapsed Time:5ms
[Decorator] Elapsed Time:11ms
[Dynamic  ] Elapsed Time:27ms
[Cglib    ] Elapsed Time:52ms

--------- test : [2] ---------
[Native   ] Elapsed Time:4ms
[Decorator] Elapsed Time:6ms
[Dynamic  ] Elapsed Time:11ms
[Cglib    ] Elapsed Time:24ms

--------- test : [3] ---------
[Native   ] Elapsed Time:4ms
[Decorator] Elapsed Time:5ms
[Dynamic  ] Elapsed Time:9ms
[Cglib    ] Elapsed Time:26ms

==================== run test : [repeatCount=3] [runCount=50000000] [java.version=1.8.0_05] ====================

--------- test : [1] ---------
[Native   ] Elapsed Time:194ms
[Decorator] Elapsed Time:211ms
[Dynamic  ] Elapsed Time:538ms
[Cglib    ] Elapsed Time:965ms

--------- test : [2] ---------
[Native   ] Elapsed Time:194ms
[Decorator] Elapsed Time:214ms
[Dynamic  ] Elapsed Time:503ms
[Cglib    ] Elapsed Time:969ms

--------- test : [3] ---------
[Native   ] Elapsed Time:190ms
[Decorator] Elapsed Time:209ms
[Dynamic  ] Elapsed Time:495ms
[Cglib    ] Elapsed Time:939ms

 

測試結果代表：jdk8 下，延續了 JDK7 下的驚天大逆轉！不過還觀察另外有一個細微的變化，從絕對值來看 cglib 在 jdk8 下的表現彷佛比 jdk7 還要差一點點，儘管只是一點點，但通過反覆屢次的執行仍然是這個趨勢（注：這個趨勢的結論並不嚴謹，只是捎帶一提，如需得出結論還需進行更多樣的對比實驗）。對象

 

結論：從 jdk6 到 jdk七、jdk8 ，動態代理的性能獲得了顯著的提高，而 cglib 的表現並未跟上，甚至可能會略微降低。傳言的 cglib 比 jdk動態代理高出 10 倍的狀況也許是出如今更低版本的 jdk 上吧。blog

以上測試用例雖然簡單，但揭示了 jdk 版本升級可能會帶來一些新技術改變，會使咱們之前的經驗失效。放在真實業務場景下時，還須要按照實際狀況進行測試後才能得出特定於場景的結論。

總之，實踐出真知，還要與時俱進地去檢視更新一些以往經驗。

 

注：上述實驗中 cglib 的版本是 3.1 。

相關文章
相關標籤/搜索
每日一句
    每一个你不满意的现在，都有一个你没有努力的曾经。
本站公眾號
   歡迎關注本站公眾號,獲取更多信息
聯繫我們 最近搜索 最新文章 沪ICP备13005482号-10 MyBatis教程 SQL 教程 MySQL教程 Java 教程 Thymeleaf 教程 Hibernate教程 Spring教程 Redis教程