SimpleService.java

package com.jqmobile.core.server.service;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import com.jqmobile.core.server.db.dao.DAOFactory;
import com.jqmobile.core.service.Service;
import com.jqmobile.core.utils.TypeArgFinder;

public class SimpleService<DAO>{
	private Class<DAO> daoClass;
	protected DAO getDao(){
		return getDao(getDAOClass());
	}
	protected <T> T getDao(Class<T> c){
		try {
			return DAOFactory.instance(c);
		} catch (Exception e) {
			throw new RuntimeException("构建DAO失败", e);
		}
	}
	@SuppressWarnings("unchecked")
	private Class<DAO> getDAOClass(){
		if(null == daoClass) daoClass = ((Class<DAO>) TypeArgFinder.find(getClass(), SimpleService.class, 0));
		return daoClass;
	}
	@SuppressWarnings("unchecked")
	protected <S> S getService(Class<S> c){
		return (S) Proxy.newProxyInstance(Thread.currentThread().getContextClassLoader(), new Class<?>[]{c}, new BaseInvocationHandler(c));
	}
	private final class BaseInvocationHandler implements InvocationHandler{
		private Class<?> c;
		BaseInvocationHandler(Class<?> c){
			this.c=c;
		}
		@Override
		public Object invoke(Object proxy, Method method, Object[] args)
				throws Throwable {
			Service annotation = c.getAnnotation(Service.class);
			if(null == annotation){
				throw new ServiceAnnotationException(c);
			}
			String impl = annotation.impl();
			Class<?> ci = Class.forName(impl, false, Thread.currentThread().getContextClassLoader());
			Object obj = ci.newInstance();
			//
			try{
				Object result = method.invoke(obj, args);
				return result;
			}catch(Throwable e){
				throw e;
			}
			//
		}
	}
}