Spring中的@Qualifier注释不起作用

  • Z时代
  • 2024-01-10
  • 分类：问答

我刚刚学习了Spring Framework，并一直在使用Spring 2.5进行学习。我用这些类创建了三个bean

Food.java

package com.spring.danipetrick;
public interface Food {
    void ingredients(); 
}

NasiGoreng.java

package com.spring.danipetrick;
public class NasiGoreng implements Food {
    public NasiGoreng() {
    }
    public void ingredients() {
        System.out.println("Rice, Coconut oil, Egg, Crackers");
    }
    @Override
    public String toString() {
        return "Nasi Goreng";
    }
}

Rendang.java

package com.spring.danipetrick;
public class Rendang implements Food {
    public void ingredients() {
        System.out.println("Beef, Coconut milk, spices");
    }
    @Override
    public String toString() {
        return "Rendang";
    }
}

PecintaKuliner.java

package com.spring.danipetrick;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
public class PecintaKuliner {
    @Autowired
    @Qualifier("nasigoreng")
    private Food food;
    @Autowired
    public void setFood(Food food) {
        this.food = food;
    }
    public Food getFood() {
        return this.food;
    }
    public void sayMaknyus() {
        System.out.println(food.toString() + " memang maknyus...");
    }
}

XML配置，qualifier-test.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xmlns:context="http://www.springframework.org/schema/context"
 xsi:schemaLocation="http://www.springframework.org/schema/beans 
     http://www.springframework.org/schema/beans/spring-beans.xsd
     http://www.springframework.org/schema/context 
     http://www.springframework.org/schema/context/spring-context.xsd">
  <context:annotation-config />
  <bean id="bondan" class="com.spring.danipetrick.PecintaKuliner">
  </bean>
  <bean id="rendang" class="com.spring.danipetrick.Rendang"/>
  <bean id="nasigoreng" class="com.spring.danipetrick.NasiGoreng" />
</beans>

最后，具有main方法的类是QualifierTestMain.java：

package com.spring.danipetrick;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class QualifierTestMain {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("/qualifier-test.xml");
        PencintaKuliner bondan = (PencintaKuliner)context.getBean("bondan");
        bondan.sayMaknyus();
    }
}

当我运行该项目时，出现这样的错误

由以下原因引起：org.springframework.beans.factory.NoSuchBeanDefinitionException：没有定义[com.spring.danipetrick.Food]类型的唯一bean：期望的单个匹配bean，但发现2：[rendang，nasigoreng]

为什么@Qualifier注释在我的情况下不起作用？

回答：

尝试仅仅去除@Autowired来自setFood()于PecintaKuliner

喜欢

@Autowired
@Qualifier("nasigoreng")
private Food food;
public void setFood(Food food) {
    this.food = food;
}

以上是 Spring中的@Qualifier注释不起作用 的全部内容， 来源链接： utcz.com/qa/432408.html

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