标志在线设计网站,虚拟主机网站建设过程,wordpress建站平台,相亲网站男人拉我做外汇一、概述 1.目标#xff1a;把Proxy修改成可以代理任意接口及其任意方法 2.思路#xff1a; (1)代理任意接口#xff1a;把接口类型作为参数传给Proxy的newProxyInstance(Class interfze) (2)代理任意方法#xff1a;用interfze.getMethods()取出所有方法#xff0c;拼接实…一、概述 1.目标把Proxy修改成可以代理任意接口及其任意方法 2.思路 (1)代理任意接口把接口类型作为参数传给Proxy的newProxyInstance(Class interfze) (2)代理任意方法用interfze.getMethods()取出所有方法拼接实现方法的字符串 二、代码 1.Movable.java 2.Tank.java 3.Proxy.java 4.Client.java 1.Movable.java 1 package proxy;
2
3 public interface Movable {
4 public void move();
5 public void stop();
6 } 2.Tank.java 1 package proxy;2 3 import java.util.Random;4 5 public class Tank implements Movable {6 7 Override8 public void move() {9 System.out.println(Tank moving.......);
10 try {
11 Thread.sleep(new Random().nextInt(2000));
12 } catch (InterruptedException e) {
13 e.printStackTrace();
14 }
15 }
16
17 Override
18 public void stop() {
19 System.out.println(Tank stopping.......);
20
21 }
22
23 } 3.Proxy.java 1 package proxy;2 3 import java.io.File;4 import java.io.FileWriter;5 import java.lang.reflect.Constructor;6 import java.lang.reflect.Method;7 import java.net.URL;8 import java.net.URLClassLoader;9
10 import javax.tools.JavaCompiler;
11 import javax.tools.JavaCompiler.CompilationTask;
12 import javax.tools.StandardJavaFileManager;
13 import javax.tools.ToolProvider;
14
15 public class Proxy {
16
17 public static Object newProxyInstance(Class interfze) throws Exception {
18
19 String rt \n\r;
20
21 //拼接实现接口方法的字符串
22 String methodStr ;
23 for(Method m: interfze.getMethods() ){
24
25 //取出方法的修饰符和返回值类型
26 String [] parts m.toString().replace(abstract , ).split(\\.);
27 String [] parts2 parts[0].split( );
28
29 methodStr
30 Override rt
31 parts2[0] parts2[1] m.getName()() { rt
32 System.out.println(\Time Proxy start...........\); rt
33 long start System.currentTimeMillis(); rt
34 m. m.getName() (); rt
35 long end System.currentTimeMillis(); rt
36 System.out.println(\花费时间\(end - start)); rt
37 System.out.println(\Time Proxy end...........\); rt
38 } ;
39 }
40
41
42 //动态代理文件的源码
43 String str
44 package proxy; rt
45
46 public class TankTimeProxy implements interfze.getName() {rt
47
48 private interfze.getName() m; rt
49
50 public TankTimeProxy( interfze.getName() m) { rt
51 this.m m; rt
52 } rt
53
54 methodStr rt
55
56 } ;
57
58 //把源码写到java文件里
59 File file new File(System.getProperty(user.dir)/src/proxy/TankTimeProxy.java);
60 FileWriter fw new FileWriter(file);
61 fw.write(str);
62 fw.flush();
63 fw.close();
64
65 //编译源码生成class,注意编译环境要换成jdk才有compiler,单纯的jre没有compiler会空指针错误
66 JavaCompiler jc ToolProvider.getSystemJavaCompiler();
67
68 //文件管事器
69 StandardJavaFileManager fileMgr jc.getStandardFileManager(null, null, null);
70
71 //编译单元
72 Iterable units fileMgr.getJavaFileObjects(file);
73
74 //编译任务
75 CompilationTask t jc.getTask(null, fileMgr, null, null, null, units);
76
77 //编译
78 t.call();
79 fileMgr.close();
80
81 //把类load到内存里
82 URL[] urls new URL[] {new URL(file:/System.getProperty(user.dir)/src/proxy/TankTimeProxy.class)};
83 URLClassLoader uc new URLClassLoader(urls);
84 Class c uc.loadClass(proxy.TankTimeProxy);
85
86 //生成实例
87 //return c.newInstance(); //c.newInstance()会调用无参数的Construtor若类没有无参的Constructor时会出错
88 Constructor ctr c.getConstructor(interfze);
89 return ctr.newInstance(new Tank());
90 }
91 } 4.Client.java 1 package proxy;2 3 import java.io.IOException;4 5 import org.junit.Test;6 7 public class Client {8 9 Test
10 public void testProxy() throws Exception{
11
12 Movable m (Movable)Proxy.newProxyInstance(Movable.class);
13 m.move();
14 m.stop();
15
16 }
17 } 三、运行结果 转载于:https://www.cnblogs.com/shamgod/p/4592359.html
