Spring boot 运用策略模式实现避免多次使用if的操作代码

public interface PayStrategy {

    
     boolean pay();
}

@Component("wechatPayStrategy")
public class WeChatPayStrategyImpl implements PayStrategy{

    
    @Override
    public boolean pay() {

        //进行微信的支付逻辑
        System.out.println("正在进行微信的支付逻辑");

        return true;
    }
}

@Component("alipayStrategy")
public class AliPayStrategyImpl implements PayStrategy {

    
    @Override
    public boolean pay() {

        //进行支付宝支付逻辑
        System.out.println("进行支付宝支付逻辑");
        return true;
    }
}

package com.example.SpringBoot_strategy.strategy.factory;

import com.example.springboot_strategy.enums.PayStrategyEnum;
import com.example.springboot_strategy.strategy.PayStrategy;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import javax.swing.plaf.synth.SynthTextAreaUI;
import java.util.Map;


@Component
public class PayStrategyFactory {

    
    @Resource
    private Map<String, PayStrategy> payStrategyMap;

    
    public PayStrategy getPayStrategy(PayStrategyEnum payStrategyEnum){

        if(!payStrategyMap.containsKey(payStrategyEnum.getClassName())){
            System.out.println("没有对应的支付策略，无法进行支付");
            return null;
        }

        return payStrategyMap.get(payStrategyEnum.getClassName());
    }
}

public enum PayStrategyEnum {
    WECHAT_PAY("wechat","wechatPayStrategy","微信支付"),
    ALIPAY("alipay","alipayStrategy","支付宝支付")
    ;

    
    private String code;

    
    private String className;

    
    private String info;

    PayStrategyEnum(String code,String className,String info){
        this.code=code;
        this.className=className;
        this.info=info;
    }


    public String getCode() {
        return code;
    }

    public String getClassName() {
        return className;
    }

    public String getInfo() {
        return info;
    }
}

@Component
public class PayStrategyContext {
    
    @Autowired
    private PayStrategyFactory payStrategyFactory;

    
    public boolean payHandle(PayDTO payDTO){
       
        //将某属性的值转换成具体的枚举。这里是根据payDTO的type字段对应枚举的code进行转换
        Optional<PayStrategyEnum> payStrategyEnumOptional = Arrays.stream(PayStrategyEnum.class.getEnumConstants())
                .filter((e) -> e.getCode().equals(payDTO.getType())).findAny();

        if(!payStrategyEnumOptional.isPresent()){
            System.out.println("匹配不到具体支付策略");
            return false;
        }
        PayStrategyEnum payStrategyEnum = payStrategyEnumOptional.get();

        PayStrategy payStrategy = payStrategyFactory.getPayStrategy(payStrategyEnum);

        //进行payDto参数的处理.....

        boolean pay = payStrategy.pay();

        //支付后的记录处理..


        return true;
        
    }
}

public class PayDTO {

    
    private String type;


    
    private BigDecimal payMoney;
    
    


    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public BigDecimal getPayMoney() {
        return payMoney;
    }

    public void setPayMoney(BigDecimal payMoney) {
        this.payMoney = payMoney;
    }

}

@RestController
@RequestMapping("pay")
public class PayController {

    @Autowired
    private PayStrategyContext payStrategyContext;

    @PostMapping
    public boolean pay(@RequestBody PayDTO payDTO){
    
        //这里因为懒。。就没有加上Service层了，直接在控制器处理
        return payStrategyContext.payHandle(payDTO);
    }
}

@Component("uNIOnPayStrategy")
public class UnionPayStrategyImp implements PayStrategy {


    
    @Override
    public boolean pay() {

        //进行银联的支付

        System.out.println("进行银联的支付逻辑");
        return true;
    }

}
复制代码

public enum PayStrategyEnum {
    WECHAT_PAY("wechat","wechatPayStrategy","微信支付"),
    ALIPAY("alipay","alipayStrategy","支付宝支付"),
    UNION_PAY("unionpay","unionPayStrategy","银联支付")
    ;

    
    private String code;

    
    private String className;

    
    private String info;

    PayStrategyEnum(String code,String className,String info){
        this.code=code;
        this.className=className;
        this.info=info;
    }


    public String getCode() {
        return code;
    }

    public String getClassName() {
        return className;
    }

    public String getInfo() {
        return info;
    }


}