IOC原理解释---控制反转

package com.bjsxt.struts2.user.action;

import java.util.Map;

import org.apache.struts2.interceptor.ApplicationAware;
import org.apache.struts2.interceptor.RequestAware;
import org.apache.struts2.interceptor.SessionAware;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;

public class LoginAction2 extends ActionSupport implements RequestAware,SessionAware, ApplicationAware {
	
	private Map<String, Object> request;
	private Map<String, Object> session;
	private Map<String, Object> application;
	
	//DI dependency injection
	//IoC inverse of control
	public String execute() {
		request.put("r1", "r1");
		session.put("s1", "s1");
		application.put("a1", "a1");
		return SUCCESS; 
	}

	@Override
	public void setRequest(Map<String, Object> request) {
		this.request = request;
	}

	@Override
	public void setSession(Map<String, Object> session) {
		this.session = session;
	}

	@Override
	public void setApplication(Map<String, Object> application) {
		this.application = application;
	}
	
	
}

   IOC就是比如：struts2将request对象传入实现了RequestAware接口的action。也就是不是自己控制，而是别人控制注入参数，属性。Spring大多都是基于IOC实现