import java.lang.reflect.Proxy;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

/**
 * CallInterceptionExampleServer - our "AppServer" which deploys some classes, registers them and provides
 * dumb naming to clients.  It will run at most one client based on the server.properties file.
 */ 
public class CallInterceptionExampleServer {
 public static Map beans; //danger (we're not thread safe but thats fine because its just an example)

 CallInterceptionExampleServer() {
  CallInterceptionExampleServer.beans = new HashMap();
 }
 
/**
 * takes a keyname, bean name and interface.  Creates the proxy and registers it.  Unlike the JBoss
 * deployers, it doesn't create a seperate classloader.  It can't undeploy or whatever.
 */ 
 public void deploy( String name, String beanname, String nterface) throws Exception{
    Object bean = Class.forName(beanname).newInstance();
    Class clsInterface = Class.forName(nterface);
    CallInterceptionExampleInvocationHandler ih = new CallInterceptionExampleInvocationHandler(bean);
    CallInterceptionExampleProxyFactory factory = new CallInterceptionExampleProxyFactory(ih);
    Object proxy = factory.createProxy(clsInterface);
    beans.put(name, proxy);
 }

 /**
  * our naming API for clients.  Call this static method with the name specified in server.properties
  */ 
 public static Object lookup( String name) {
   return beans.get(name);
 }

 /**
  * reads our deployments from server.properties.  Gets their "name" (like EJBName or JNDIName), bean class 
  * and interface (like EJB's Remote or Local) and passes them to deploy(s,s,s).  Finally we run whatever
  * is specified by the "run" property.
  */ 
 public void deployments() throws Exception {
   InputStream propstream = Thread.currentThread().getContextClassLoader().getResourceAsStream("server.properties");
   Properties props = new Properties();
   props.load(propstream);
   propstream.close();
   int num = Integer.decode((String)props.get("number")).intValue(); //deployments must say how many

   String bean = "bean";
   String nterface = "interface";
   String name = "name";

   for (int n = 0; n < num; n++) {
     String beanprop = bean+n+"."+bean;
     String interfaceprop = bean+n+"."+nterface;
     String nameprop = bean+n+"."+name;
     deploy( (String)props.get(nameprop), (String)props.get(beanprop), (String)props.get(interfaceprop) );
   }

   doRun((String)props.get("run"));
 }

 /**
  * runs our client (its like the servlet API kinda but not really, maybe more like JMX services)
  */  
 public void doRun(String clazz) throws Exception {
  Object obj = Class.forName(clazz).newInstance(); 
  Runnable runObj = (Runnable) obj;
  runObj.run();
 }

 public static void main(String args[]) {
   try { 
     CallInterceptionExampleServer svr = new CallInterceptionExampleServer();
     svr.deployments();
   } catch (Exception e) {
     e.printStackTrace();
   }
 }

}