第十贴代理、概念框架图、动态代理（2） - 黑马程序员技术交流社区

package com.gjy.DynamicProxy;
public class Proxy {
public static Object newProxyIntenct(Class infac,InvocationHandler h) throws Exception{
String br ="\r\n";
String methString ="";
Method[] method = infac.getMethods();
for(Method m: method){
methString = " @Override"+ br +
" public void "+m.getName()+"() {"+ br +
" try {" + br +
" Method md ="+ infac.getName()+".class.getMethod(\""+m.getName()+"\");"+ br +
" h.invoke(this,md);" + br +
" }catch (Exception e){ "+ br+
" e.printStackTrace();" + br +
" }" + br +
" }";
}
String src = "package com.gjy.DynamicProxy;" + br +
"import java.lang.reflect.Method;" + br +
"public class $Proxy implements "+infac.getName()+"{" + br +
" private com.gjy.DynamicProxy.InvocationHandler h;" + br +
" public $Proxy(InvocationHandler h) {" + br +
" super();" + br +
" this.h = h;" + br +
" }" + br + br +
methString +br +
"}";
MakFileUtil.createFile("D:/src/com/gjy/DynamicProxy");
//生成java文件
String fileName ="D:\\src\\com\\gjy\\DynamicProxy\\$Proxy.java";
System.out.println(fileName);
File file = new File(fileName);
FileWriter fWriter = new FileWriter(file);
fWriter.write(src);
fWriter.flush();
fWriter.close();
//生成class文件,jdk6提供的工具类
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
//System.out.println(compiler.getClass().getName());
StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
Iterable units = fileManager.getJavaFileObjects(fileName);
CompilationTask task = compiler.getTask(null, fileManager, null, null, null, units);
task.call();
fileManager.close();
//装载到内存,生成新对象
URL[] urls = new URL[]{new URL("file:/"+"D:\\src\\")};
URLClassLoader loader = new URLClassLoader(urls);
Class c = loader.loadClass("com.gjy.DynamicProxy.$Proxy");
//通过有参的构造器反射生成代理类的实例
Constructor ctr = c.getConstructor(InvocationHandler.class);
Object obj = (Object) ctr.newInstance(h);
return obj;
}
}

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package com.gjy.DynamicProxy;
public interface InvocationHandler {
void invoke(Object o,Method m);
}

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package com.gjy.DynamicProxy;
public class TimeInvocationHandler implements InvocationHandler {
private Object target;
public TimeInvocationHandler(Object target) {
this.target = target;
}
@Override
public void invoke(Object o, Method m) {
long time1 = System.currentTimeMillis();
System.out.println("time1="+time1);
try {
m.invoke(target);
} catch (Exception e) {
e.printStackTrace();
}
long time2 = System.currentTimeMillis();
System.out.println("time2="+time2);
System.out.println("Tank 的启动时间:"+(time2-time1));

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package com.gjy.DynamicProxy;
public class Tank implements Moveable{
@Override
public void move() {
int a = 5;int b = 6;int c = 0; int d = 0;
for (int i = 0; i < 1000; i++) {
d = i;
}
c = ((a+b)/2)*12;
System.out.println("TanK moving..Tank 的速度是"+c);
}

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package com.gjy.DynamicProxy;
public interface Moveable {
void move();
}
}

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package com.gjy.DynamicProxy;
public class TestTank {
public static void main(String[] args) throws Exception{
Tank t = new Tank();
Moveable moveable = (Moveable) Proxy.newProxyIntenct(Moveable.class,new TimeInvocationHandler(t));
moveable.move();
}
}

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package com.gjy.DynamicProxy;
public class MakFileUtil {
public static void createFile(String pathstr) throws IOException{
//创建多级目录
String path = pathstr;
//为指定字符串构造一个 string tokenizer。 "/"字符是分隔标记的分隔符。分隔符字符本身不作为标记。
StringTokenizer st = new StringTokenizer(path,"/");
String path1 = st.nextToken()+"/";
String path2 = path1;
while(st.hasMoreTokens())
{
path1 = st.nextToken()+"/";
path2 += path1;
File inbox = new File(path2);
if(!inbox.exists())
inbox.mkdir();
}
}
}

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public class $Proxy implements com.gjy.DynamicProxy.Moveable{
private com.gjy.DynamicProxy.InvocationHandler h;
public $Proxy(MakFileUtil h) {
super();
this.h = h;
}
@Override
public void move() {
try {
Method md =com.gjy.DynamicProxy.Moveable.class.getMethod("move");
h.invoke(this,md);
}catch (Exception e){
e.printStackTrace();
}
}
}

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package com.gjy.DynamicProxy;
public class LogInvocationHandler implements InvocationHandler {
private Object target;
public LogInvocationHandler(Object target) {
this.target = target;
}
@Override
public void invoke(Object o, Method m) {
System.out.println("Tank start...........");
try {
m.invoke(target);
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("Tank stop..............");
}
}

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package com.gjy.DynamicProxy;
public class TestTank {
public static void main(String[] args) throws Exception{
Tank t = new Tank();
Moveable moveable = (Moveable) Proxy.newProxyIntenct(Moveable.class,new TimeInvocationHandler(t));
Moveable moveable2 = (Moveable) Proxy.newProxyIntenct(Moveable.class, new LogInvocationHandler(moveable));
moveable2.move()；
}
}

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