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NoSuchBeanDefinitionException：未定义名为'name'的bean

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我正在尝试一个非常基本的例子 . 我试图看到其他堆栈溢出的答案，但无法解决这个问题 . 我是这个领域的新手，如果我遗漏了任何东西，请告诉我 .

这是我的错误日志：

2017年12月11日上午8:40:20 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions INFO：从类路径资源加载XML bean定义[BeanDefinition.xml]线程“main”org.springframework.beans中的异常 . factory.NoSuchBeanDefinitionException：在org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition（AbstractBeanFactory）的org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition（DefaultListableBeanFactory.java:638）中没有定义名为'MySpringBeanWithDepenency'的bean . java：1159）org.springframework上的org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:282）org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:195） .context.support.AbstractApplicationContext.getBean（AbstractApplicationContext.java:973）在model.main.Main.main（Main.java:18）

这显然说它找不到MySpringBeanWithDepenency

这是我的BeanDefinition.xml

<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:aop="http://www.springframework.org/schema/aop"
   xmlns:context="http://www.springframework.org/schema/context"
   xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
       http://www.springframework.org/schema/aop
       http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
       http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-2.5.xsd">

<context:component-scan base-package="model.testbean" />
<context:component-scan base-package="model.writer" />

这是我的主要课程：

package model.main;

/**
 * Created by barora on 12/10/2017.
 */

import org.springframework.beans.factory.BeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import model.testbean.MySpringBeanWithDepenency;

public class Main {
    public static void main(String args[]){
        ApplicationContext context = new ClassPathXmlApplicationContext(
                "BeanDefinition.xml");
        BeanFactory factory = context;
        MySpringBeanWithDepenency test = (MySpringBeanWithDepenency) factory.getBean("MySpringBeanWithDepenency");
        test.run();
    }
}

这是我的MySpringBeanWithDepenency

package model.testbean;

/**
 * Created by barora on 12/10/2017.
 */

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

import org.springframework.context.annotation.ComponentScan;
import org.springframework.stereotype.Component;

import model.writer.IWriter;
import org.springframework.stereotype.Service;


@Service
public class MySpringBeanWithDepenency {

    private IWriter writer;

    @Autowired
    public void setWriter(IWriter writer){
        this.writer = writer;
    }

    public void run(){
        String s = "This is my test";
        writer.writer(s);
    }
}

这是我的文件夹结构：

enter image description here

java spring spring-mvc

2 回答

  • 1

    尝试调试添加：

    System.out.println("Bean names: " + Arrays.toString(context.getBeanNamesForType(MySpringBeanWithDependency.class)));

    如果这打印出一个空列表，那么您的类路径扫描就会出现问题 . 如果它打印一个名称，那么这是一个可以用来获取bean的名称 .

    或者，使用 factory.getBean(MySpringBeanWithDependency.class) 代替 factory.getBean(String name) ，这样您就不需要知道Spring为您的bean提供了什么名称 .

    回复于
  • 2

    试试 MySpringBeanWithDepenency test = (MySpringBeanWithDepenency) factory.getBean(MySpringBeanWithDepenency.class);

    EDITED

    所以我've recreated code using given project structure. It works with exception that I' ve使用了以下代码 IWriter

    package model.writer;

    public interface IWriter {

        void writer(String s);
    }

    并实施

    package model.writer;

import org.springframework.stereotype.Component;

@Component
public class NiceWriter implements IWriter {
    public void writer(String s) {

    }
}

    EDITED 2 如果你想为 IWriter 接口提供两个实现，并且两者都应该是spring managed beans，你需要帮助spring容器决定你想要它自动装配哪个 . 请使用 @Qualifier . 有关详细信息，请参见tutorial

    回复于

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