proxy --- 2 获取任意接口的proxy

此章只要在client 传入一个class 就可以获取他的proxy （  此版本有bug 在一章里面会取消几个bug）
public class Proxya {
public static Object getProxy(Class proxyinterface)throws Exception{

Method[] methods = proxyinterface.getMethods();
String methodStr = "";
for(Method m : methods){
methodStr += "@Override\r\n";
methodStr +="public void " + m.getName() + "(){" +
"long startTime = System.currentTimeMillis();"+
"car.move();"+
"long endTime = System.currentTimeMillis();"+
"System.out.println(\"moive time is \" + (endTime-startTime));"+
"}";
}


String src = "package com.wjj.myproxy;"+

"public class CarTimeProxy implements "+proxyinterface.getName()+" {"+

"Moveable car = null;"+


"public CarTimeProxy(Moveable car) {"+
"super();"+
"this.car = car;"+
"}"+methodStr+

"}";

String fileName = System.getProperty("user.dir") +"/src/com/wjj/myproxy/CarTimeProxy.java";

File file = new File(fileName);
FileWriter writer = new FileWriter(file);
writer.write(src);
writer.flush();
writer.close();

JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
StandardJavaFileManager fileMgr = compiler.getStandardFileManager(null, null, null);
Iterable units = fileMgr.getJavaFileObjects(fileName);
CompilationTask t = compiler.getTask(null, fileMgr, null, null, null, units);
t.call();
fileMgr.close();


URL[] urls = new URL[]{new URL("file:/" + System.getProperty("user.dir")+"/src")};
URLClassLoader ul = new URLClassLoader(urls);
Class clazz = ul.loadClass("com.wjj.myproxy.CarTimeProxy");
System.out.println(clazz);


Constructor cos = clazz.getConstructor(Moveable.class);
return cos.newInstance(new Car());
}
}



===========================================
client 代码
public class Client {
public static void main(String[] args) {
try {
Moveable ca = (Moveable)Proxya.getProxy(Moveable.class);
ca.move();
} catch (Exception e) {
e.printStackTrace();
}
}
}