IOC的类型（DI注入）

　　从注入方法上看，IOC可以分为三种类型：构造函数注入，set方法属性注入，接口方法注入，spring中支持前两种注入方式。

/**
 * 导演
 * Created by qiqi on 2018/11/20 9:53
 */
public class DirectorService {

    //剧本1
    public void direct1() {
        //安排刘德华出演革离
        GeLi geLi = new LiuDeHua();
        //构造函数将革离注入到墨攻剧本
        MoAttackService moAttackService = new MoAttackService(geLi);
        //城门守卫询问
        moAttackService.cityGateAsk();
    }

    //剧本2
    public void direct2() {
        //安排刘德华出演革离
        GeLi geLi = new LiuDeHua();
        //set方法注入
        MoAttackService moAttackService = new MoAttackService();
        moAttackService.setGeLi(geLi);
        //城门守卫询问
        moAttackService.cityGateAsk();
    }

    //剧本3
    public void direct3() {
        //安排刘德华出演革离
        GeLi geLi = new LiuDeHua();
        //接口方法注入
        MoAttackService moAttackService = new MoAttackService();
        moAttackService.injectGeLi(geLi);
        //城门守卫询问
        moAttackService.cityGateAsk();
    }

}

/**
 * 墨攻剧本
 * Created by qiqi on 2018/11/20 9:42
 */
public class MoAttackService implements Acctor {
    private GeLi geLi;

    //构造函数注入
    public MoAttackService(GeLi geLi) {
        this.geLi = geLi;
    }
    public MoAttackService() {
    }

    //set方法注入
    public void setGeLi(GeLi geLi) {
        this.geLi = geLi;
    }


    //城门守卫询问
    public void cityGateAsk() {
        geLi.responseAsk("I am MoAttack Geli");
    }
　　//重写接口方法
    @Override
    public void injectGeLi(GeLi geLi) {
        geLi.responseAsk("I am MoAttack Geli");
    }
}

/**
 *接口方法
 * Created by qiqi on 2018/11/20 10:16
 */
public interface Acctor {
    void injectGeLi(GeLi geLi);
}

/**
 * 革离
 * Created by qiqi on 2018/11/20 9:45
 */
public class GeLi {
    private String name;

    //回答
    public String responseAsk(String name) {
        return this.name = name;
    }
}

/**
 * Created by qiqi on 2018/11/20 9:55
 */
public class LiuDeHua extends GeLi {
}

由于接口注入需要额外声明一个接口，增加了类的数目，其本质与效果与set方法注入并无区别，所以不建议接口注入