package com.bjsxt.proxy;

import java.io.File;
import java.io.FileWriter;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

import javax.tools.JavaCompiler;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
import javax.tools.JavaCompiler.CompilationTask;

public class Proxy {
    public static Object newProxyInstance(Class infce, InvocationHandler h) throws Exception { //JDK6 Complier API, CGLib, ASM
        String methodStr = "";
        String rt = "\r\n";
        
        Method[] methods = infce.getMethods();
        /*
        for(Method m : methods) {
            methodStr += "@Override" + rt + 
                         "public void " + m.getName() + "() {" + rt +
                             "   long start = System.currentTimeMillis();" + rt +
                            "   System.out.println(\"starttime:\" + start);" + rt +
                            "   t." + m.getName() + "();" + rt +
                            "   long end = System.currentTimeMillis();" + rt +
                            "   System.out.println(\"time:\" + (end-start));" + rt +
                         "}";
        }
        */
        for(Method m : methods) {
            methodStr += "@Override" + rt + 
                         "public void " + m.getName() + "() {" + rt +
                         "    try {" + rt +
                         "    Method md = " + infce.getName() + ".class.getMethod(\"" + m.getName() + "\");" + rt +
                         "    h.invoke(this, md);" + rt +
                         "    }catch(Exception e) {e.printStackTrace();}" + rt +
                        
                         "}";
        }
        
        String src = 
            "package com.bjsxt.proxy;" +  rt +
            "import java.lang.reflect.Method;" + rt +
            "public class $Proxy1 implements " + infce.getName() + "{" + rt +
            "    public $Proxy1(InvocationHandler h) {" + rt +
            "        this.h = h;" + rt +
            "    }" + rt +
            
            
            "    com.bjsxt.proxy.InvocationHandler h;" + rt +
                            
            methodStr +
            "}";
        String fileName = 
            "src/com/bjsxt/proxy/$Proxy1.java";
        File f = new File(fileName);
        FileWriter fw = new FileWriter(f);
        fw.write(src);
        fw.flush();
        fw.close();
        
        //compile
        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();
        
        //load into memory and create an instance
        URL[] urls = new URL[] {new URL("file:/" + "src/")};
        URLClassLoader ul = new URLClassLoader(urls);
        Class c = ul.loadClass("com.bjsxt.proxy.$Proxy1");
        System.