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Spring @Autowired 注入到List和Map

需求

需求

对商品进行价格计算，计算价格设计到到元素是不固定到。有到商品涉及到优惠卷有到商品涉及到团购，有到商品全都涉及到。

每一个环节计算完成以后，要把价格传递给下一个环节接着计算。

抽象出一个模型就是流水线pipeline，一个阶段一个阶段处理，上一个阶段处理完成以后传递给下一个阶段

Spring实现pipeline

实现方式

Spring 使用 @Autowired + @Order 实现同一类型的实例注入到集合（List or Map）

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public interface PriceCommonProcessor {



    public Integer process(Integer lastPrice);

}

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import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import lombok.extern.slf4j.Slf4j;

@Component
@Order(1)
@Slf4j
public class A_Processor implements PriceCommonProcessor{

    @Override
    public Integer process(Integer lastPrice) {
        log.info("A >>>> processor");
        return lastPrice - 100;
    }

}

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import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import lombok.extern.slf4j.Slf4j;

@Component
@Order(2)
@Slf4j
public class B_Processor implements PriceCommonProcessor {

    @Override
    public Integer process(Integer lastPrice) {
        log.info("B >>>> processor");
        return lastPrice - 200;
    }

}

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import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

import lombok.extern.slf4j.Slf4j;

@Component
@Order(3)
@Slf4j
public class C_Processor implements PriceCommonProcessor{

    @Override
    public Integer process(Integer lastPrice) {
        log.info("C >>>> processor");
        return lastPrice - 300;

    }

}

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import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.example.demo.processor.PriceCommonProcessor;

@RestController
public class TestController {

    @Autowired
    private List<PriceCommonProcessor> list;

    @GetMapping("dd")
    public Integer getPrice(Integer lastPrice) {

        for (PriceCommonProcessor processor : list) {
            lastPrice = processor.process(lastPrice);
        }

        return lastPrice;

    }

}

执行命令$ curl 'localhost:8080/dd?lastPrice=1000'

控制台日志输出

  • A >>>> processor
  • B >>>> processor
  • C >>>> processor
  1. @Autowired 可以直接注入同一type的实例到list，注入的顺序就是被@Order标记到顺序，从而形成pipeline模型
  2. 不仅可以顺序注入到List， 还可以注入到Map
 
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import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import com.example.demo.processor.PriceCommonProcessor;

import lombok.extern.slf4j.Slf4j;

@RestController
@Slf4j
public class TestController {

    @Autowired
    private List<PriceCommonProcessor> list;

    @Autowired
    private Map<String, PriceCommonProcessor> map;

    @GetMapping("dd")
    public Integer getPrice(Integer lastPrice) {

        map.entrySet().forEach(e -> {
            log.info("{}--->>{}", e.getKey(), e.getValue().getClass().getName() );
        });
        return 1;

    }

}
  • a_Processor—>>com.example.demo.processor.A_Processor
  • b_Processor—>>com.example.demo.processor.B_Processor
  • c_Processor—>>com.example.demo.processor.C_Processor