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java 反射提取类信息, 动态代理 和过滤某些方法演示
java 反射提取类信息, 动态代理 和过滤某些方法演示
package org.rui.classts.reflects; import java.lang.reflect.Constructor; import java.lang.reflect.Method; import java.util.regex.Pattern; /** * 提取 类的 方法 构造器 * @author lenovo * */ //{args:ShowMethods} //查看一个类的所有方法和构造器 public class ShowMethods { private static String usage="usage:showMethod qualified.class.mane"; private static Pattern p=Pattern.compile("\\w+\\."); public static void main(String[] args) throws ClassNotFoundException { //System.out.println(args[0]+" : "+args[1]); args=new String[1]; args[0]="org.rui.classts.reflects.ShowMethods"; //args[1]="java.awt.Color"; if(args.length<1) { System.out.println(usage); System.exit(0); } int lines=0; Class<?> c=Class.forName(args[0]); Method[] m=c.getMethods(); Constructor[] constructor=c.getConstructors(); if(args.length==1) { for(Method mt:m) { //System.out.println("tostring:"+mt.toString()); //去掉带 点和前面的字符 如 xx.ss. System.out.println("m1:"+ p.matcher(mt.toString()).replaceAll("") ); } //---------------------------------------- for(Constructor con:constructor) System.out.println("c1:"+ p.matcher(con.toString()).replaceAll("") ); lines=m.length+constructor.length; } else { for(Method mt:m) { if(mt.toString().indexOf(args[1])!=-1) { System.out.println("m2:"+ p.matcher(mt.toString()).replaceAll("") ); lines++; } } //---------------------------------------- for(Constructor con:constructor) { if(con.toString().indexOf(args[1])!=-1) { System.out.println("c2:"+ p.matcher(con.toString()).replaceAll("") ); lines++; } } } } }
package org.rui.classts.reflects; /** * 简单动态代理 实现 * @author lenovo * */ interface Interface { void doSomething(); void somethingElse(String arg); } //class------------------ class RealObject implements Interface{ public void doSomething() { System.out.println("RealObject doSomething"); } public void somethingElse(String arg) { System.out.println("RealObject somethingElse:"+arg); } } //class-SimpleProxy----------------- class SimpleProxy implements Interface{ private Interface proxied; public SimpleProxy(Interface proxied){this.proxied=proxied;} //method public void doSomething() { System.out.println("SimpleProxy doSomething"); proxied.doSomething(); } public void somethingElse(String arg) { System.out.println("SimpleProxy somethingElse:"+arg); proxied.somethingElse(arg); } } public class SimpleProxyDemo { public static void consumer(Interface inta) { inta.doSomething(); inta.somethingElse("bonobo"); } //main---------- public static void main(String[] args) { //Interface o=new RealObject(); //真实对象去实现 consumer(new RealObject()); //代理去实现 consumer(new SimpleProxy(new RealObject())); } }
package org.rui.classts.reflects; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; //DynamicProxyHandler class DynamicProxyHandler implements InvocationHandler{ private Object proxied; public DynamicProxyHandler(Object proxied) { this.proxied=proxied; } @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { System.out.println("proxy:=="+proxy.getClass() +"\nmethod:=="+method +" \nargs:"+args); if(args!=null) for(Object o:args) System.out.println("arg:"+o); //把 实际对象给 proxied return method.invoke(proxied, args); } } class SimpleDynamicProxy{ public static void consumer(Interface iface) { iface.doSomething(); iface.somethingElse("bonobo=="); } public static void main(String[] args) { RealObject robj=new RealObject(); consumer(robj); //代理 //返回一个指定接口的代理类实例,该接口可以将方法调用指派到指定的调用处理程序。 Interface proxy=(Interface) Proxy.newProxyInstance( Interface.class.getClassLoader(), // 定义代理类的类加载器 new Class[]{Interface.class},// 代理类要实现的接口列表 new DynamicProxyHandler(robj)//指派方法调用的调用处理程序 ); consumer(proxy); } }
package org.rui.classts.reflects; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; /** * 动态代理过滤某些方法 的演示 * @author lenovo * */ class MethodSelector implements InvocationHandler { private Object obj; public MethodSelector(Object o){this.obj=o;} public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { //System.out.println("proxy:"+proxy.getClass().getSimpleName()); //可以拦截特殊处理 if(method.getName().equals("interesting")) { System.out.println("proxy detected the interesting method"); } return method.invoke(obj, args); } } // interface interface SomeMethod { void boring1(); void interesting(String arg); void boring2(); void boring3(); } //------------------------------ class Implementation implements SomeMethod { public void boring1() { System.out.println("boring1"); } public void interesting(String arg) { System.out.println("interesting:"+arg); } public void boring2() { System.out.println("boring2"); } public void boring3() { System.out.println("boring3"); } } // public class SelectingMethods { public static void main(String[] args) { //代理测试 SomeMethod proxy =(SomeMethod)Proxy.newProxyInstance( SomeMethod.class.getClassLoader(), // 定义代理类的类加载器 new Class[]{SomeMethod.class},// 代理类要实现的接口列表 new MethodSelector(new Implementation())//指派方法调用的调用处理程序 ); proxy.boring1(); proxy.boring2(); proxy.interesting("bonobo"); proxy.boring3(); } }
对比测试
package org.rui.classts; import org.rui.classts.chilnd.*; public class PetCount4 { public static void main(String[] args) { Pet p=new Dog(); Class c=Pet.class; Class c1=Dog.class; Class c2=Cat.class; //对象对比 类 if(p instanceof Dog){ System.out.println("true"); }else System.out.println("fales"); //class 对比 对象 if(c.isInstance(p)){ System.out.println("true"); }else System.out.println("fales"); // class对比class if(c.isAssignableFrom(c1)){ System.out.println("true"); }else System.out.println("fales"); if(c2.isAssignableFrom(c1)){ System.out.println("true"); }else System.out.println("fales"); System.out.println("c==c1:"+(c==c1)); System.out.println("c.equals(c1:"+(c.equals(c1))); System.out.println("c==Pet.class:"+(c==Pet.class)); System.out.println("c.equals(Pet.class:"+(c.equals(Pet.class))); } }
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