通过处理器类型获得处理器对象

使用两种方法通过处理器类型获得处理器对象

1、通过@postConstruct注解，构造函数之后注册对象

2、通过继承ApplicationContextAware接口，实现setApplicationContext方法。

package rpg.test;
import javax.annotation.PostConstruct;

import org.springframework.beans.factory.annotation.Autowired;

public abstract class AbstractHandler {

    @Autowired
    private BManager bmanager;

    @PostConstruct
    public void init() {
        bmanager.regist(this);
        System.out.println("加载---"+this);
    }

    public abstract TestType getType();

}

package rpg.test;
import org.springframework.stereotype.Component;

@Component
public class AHandler extends AbstractHandler {

    @Override
    public TestType getType() {
        return TestType.A;
    }

}

package rpg.test;
import org.springframework.stereotype.Component;

@Component
public class BHandler extends AbstractHandler {

    @Override
    public TestType getType() {
        return TestType.B;
    }

}

package rpg.test;

public enum TestType {
    A,
    B,
    C,
    D,
    E;
}

package rpg.test;
import java.util.Collection;
import java.util.EnumMap;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

@Component
public class AManager implements ApplicationContextAware {

    private EnumMap<TestType, AbstractHandler> handlers;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        Collection<AbstractHandler> collection = applicationContext.getBeansOfType(AbstractHandler.class).values();
        handlers = new EnumMap<>(TestType.class);
        for (AbstractHandler abstractHandler : collection) {
            handlers.put(abstractHandler.getType(), abstractHandler);
            System.out.println(this+"加载---"+abstractHandler);
        }
    }

    public AbstractHandler getHandler(TestType testType) {
        return handlers.get(testType);
    }
}

package rpg.test;
import java.util.EnumMap;

import org.springframework.stereotype.Component;

@Component
public class BManager {
    private EnumMap<TestType, AbstractHandler> handlers = new EnumMap<>(TestType.class);

    public void regist(AbstractHandler handler) {
        handlers.put(handler.getType(), handler);
    }

    public AbstractHandler getHandler(TestType testType) {
        return handlers.get(testType);
    }
}

package rpg.test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class TestMain {

    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("classpath*:server.xml");
        AManager aManager = (AManager) context.getBean("AManager");
        AbstractHandler handler = aManager.getHandler(TestType.B);
        System.out.println(handler);
    }

}