Java的动态编译 cglib / asm 等

http://www.qqread.com/netbase/w478517.html 

菜鸟课堂：几个动态代理Proxy工具性能比较

JDK 6和CGLib cglib-nodep-2.2.jar对比结果：

JDK Proxy: 1,049,937 calls/s

CGLIB: 2,820,130 calls/s

如果使用cglib以前版本，性能更快：

JDK Proxy: 1,037,575 calls/s

CGLIB: 3,112,727 calls/s

而JDK 6和JavaAssit 3.11测试结果如下：

JDK Proxy: 1,037,575 calls/s

JAVAASSIST: 626,695 calls/s 

从数据上看，cglib性能最好。但是和ASM、直接调用比较还不知道。 

public class ProxyPerformanceComparison2 {

public static void main(String[] args) throws Exception {

Callable<integer> jdkProxy = (Callable<integer>)

Proxy.newProxyInstance(ClassLoader.getSystemClassLoader(), new Class[] {

Callable.class },

new JdkHandler(new Counter()));

ProxyFactory f = new ProxyFactory();

f.setInterfaces(new Class[] { Callable.class });

Class c = f.createClass();

Callable<integer> cglibProxy = (Callable<integer>) c.newInstance();

((ProxyObject) cglibProxy).setHandler

(new JavaAssitInterceptor(new Counter()));

for (int i2 = 0; i2 < 10; i2++) {

iterate(jdkProxy, "JDK Proxy: ");

iterate(cglibProxy, "JAVAASSIST: ");

System.err.println();

}

}

static final DecimalFormat format = new DecimalFormat();

static void iterate(Callable<integer> callable, String label)

throws Exception {

int count = 10000000;

long time = System.currentTimeMillis();

int total = 0;

for (int i = 0; i < count; i++) {

total += callable.call();

}

time = System.currentTimeMillis() - time;

System.err.println(label + format.format

(count * 1000 / time) + " calls/s");

}

static class JdkHandler implements InvocationHandler {

final Object delegate;

JdkHandler(Object delegate) {

this.delegate = delegate;

}

public Object invoke

(Object object, Method method, Object[] objects) throws Throwable {

return method.invoke(delegate, objects);

}

}

static class JavaAssitInterceptor implements MethodHandler {

final Object delegate;

JavaAssitInterceptor(Object delegate) {

this.delegate = delegate;

}

public Object invoke

(Object self, Method m, Method proceed, Object[] args) throws Throwable {

return m.invoke(delegate, args);

}

}

static class Counter implements Callable<integer> {

int count = 0;

public Integer call() throws Exception {

return count++;

}

}

}

   

---------------------------------------------  

http://www.zx2010.com/program/java-jdk-cglib-proxy-performance-comparison.asp 

JDK动态代理与CGLIB代理的性能测试

result:

JDK Proxy: 765,092 calls/s

CGLIB:     1,503,268 calls/s

JDK Proxy: 716,132 calls/s

CGLIB:     991,607 calls/s

JDK Proxy: 601,820 calls/s

CGLIB:     1,128,052 calls/s 

结果也仅仅说明了cglib性能提高了2倍左右。还是不行。 

import java.lang.reflect.*;
import net.sf.cglib.proxy.*;
import java.text.*;
import java.util.concurrent.Callable;

public class ProxyPerformanceComparison {  
  public static void main(String[] args) throws Exception {    
    Callable<Integer> jdkProxy = (Callable<Integer>) java.lang.reflect.Proxy.newProxyInstance(       
                                  ClassLoader.getSystemClassLoader(),
                                  new Class[] { Callable.class },       
                                  new JdkHandler(new Counter())    
                                  );    
    Enhancer enhancer = new Enhancer();    
    enhancer.setCallback(new CglibInterceptor(new Counter()));    
    enhancer.setInterfaces(new Class[] { Callable.class });    
    Callable<Integer> cglibProxy = (Callable<Integer>) enhancer.create();  

    for (int i2 = 0; i2 < 10; i2++) {      
        iterate(jdkProxy,    "JDK Proxy: ");   
        iterate(cglibProxy,  "CGLIB:     ");
        System.err.println();
    }
  } 

  static final DecimalFormat format = new DecimalFormat();

  static void iterate(Callable<Integer> callable, String label)  throws Exception {
    int count = 10000000;  
    long time = System.currentTimeMillis();  
    int total = 0;   
    for (int i = 0; i < count; i++) {   
        total += callable.call(); 
    }    
    time = System.currentTimeMillis() - time;    
    System.err.println(label  + format.format(count * 1000 / time) + " calls/s");  } 

    /* inner class */
    static class JdkHandler implements java.lang.reflect.InvocationHandler {   
      final Object delegate;    
      JdkHandler(Object delegate) {      
        this.delegate = delegate;    
      }   
      public Object invoke(Object object, Method method, Object[] objects) throws Throwable {
         return method.invoke(delegate, objects);    
      }
    } 

    /* inner class */
    static class CglibInterceptor implements MethodInterceptor {   
      final Object delegate;   

      CglibInterceptor(Object delegate) {     
        this.delegate = delegate;    
      }    
    
      public Object intercept(Object object, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {      
        return methodProxy.invoke(delegate, objects);   
      }
    }

    /* inner class */
    static class Counter implements Callable<Integer> {    
      int count = 0;
      public Integer call() throws Exception {
        return count++;    
      } 
    }
}

------------------------------

http://www.javaeye.com/topic/314894

10000次对象复制测试结果(ms)： 

task 直接复制                  31 

task java标准反射复制          610 

task cglib Fast复制(不好的写法) 890 

task cglib beancopier复制    125

使用beancopy，意思是把第一个bean的数据copy到第二个。貌似没有什么用。是2个对象之间复制。 

o = clazz0.newInstance();  
BeanCopier beanCopier = BeanCopier.create(clazz0, managelogVO.getClass(), false);  
beanCopier.copy(o,managelogVO, null);  

直接调用 

ManagelogVO newVO = new ManagelogVO();  
    newVO.setLogid(managelogVO.getLogid());  
    newVO.setOprcode(managelogVO.getOprcode());  

Java反射

Object o  = null;  
        try {  
            Class clazz = Class.forName("demo.cglib.ManagelogVO");  
            o = clazz.newInstance();  
            Method setterMethod = null;  
            Method getterMethod = null;  
            Object v = null;  
              
            setterMethod = clazz.getMethod("setLogid", new Class[]{Long.class});  
            getterMethod = clazz.getMethod("getLogid", null);             
            v = getterMethod.invoke(managelogVO, null);  
            setterMethod.invoke(o, new Object[]{v});  
              
            setterMethod = clazz.getMethod("setOprcode", new Class[]{String.class});  
            getterMethod = clazz.getMethod("getOprcode", null);           
            v = getterMethod.invoke(managelogVO, null);  
            setterMethod.invoke(o, new Object[]{v});  

cglib反射

Object o  = null;  
try {  
    Class clazz0 = Class.forName("demo.cglib.ManagelogVO");  
              
    FastClass clazz = FastClass.create(clazz0);           
    o = clazz.newInstance();  
    FastMethod setterMethod = null;  
    FastMethod getterMethod = null;  
    Object v = null;  
      
    setterMethod = clazz.getMethod("setLogid", new Class[]{Long.class});  
    getterMethod = clazz.getMethod("getLogid", null);             
    v = getterMethod.invoke(managelogVO, new Object[]{});  
    setterMethod.invoke(o, new Object[]{v});  
      
    setterMethod = clazz.getMethod("setOprcode", new Class[]{String.class});  
    getterMethod = clazz.getMethod("getOprcode", null);           
    v = getterMethod.invoke(managelogVO, new Object[]{});  
    setterMethod.invoke(o, new Object[]{v});  

---------------------------

http://www.ibm.com/developerworks/cn/java/j-lo-asm30/index.html

使用asm实现AOP

http://www.oschina.net/bbs/thread/4239

cglib的例子