春季-注入自動裝配的依賴項失敗

Question

服務器中出現以下錯誤：

嚴重：上下文初始化失敗

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'productController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.packt.webstore.domain.repository.ProductRepository com.mkyong.common.controller.ProductController.productRepository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.packt.webstore.domain.repository.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425)
    at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442)
        at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458)
        at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:339)
        at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:306)
        at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:127)
        at javax.servlet.GenericServlet.init(GenericServlet.java:158)
        at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1284)
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1197)
        at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1087)
        at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5262)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5550)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1575)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1565)
        at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
        at java.util.concurrent.FutureTask.run(FutureTask.java:138)
        at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
        at java.lang.Thread.run(Thread.java:662)
    Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.packt.webstore.domain.repository.ProductRepository com.mkyong.common.controller.ProductController.productRepository; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.packt.webstore.domain.repository.ProductRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:502)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:282)
... 29 more

這是代碼：

ProductController.java

package com.mkyong.common.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import com.packt.webstore.domain.repository.ProductRepository;

@Controller
public class ProductController {

    @Autowired
    private ProductRepository productRepository;    

    @RequestMapping("/products")
    public String list(Model model)
    {
      model.addAttribute("product",productRepository.getAllProducts());
      return "products";
    }
}

Product.java

package com.packt.webstore.domain;

import java.math.BigDecimal;

public class Product {
    private String productId;
    private String name;
    private BigDecimal unitPrice;
    private String description;
    private String manufacturer;
    private String category;
    private long unitInStock;
    private long unitInOrder;
    public String getProductId() {
        return productId;
    }
    public void setProductId(String productId) {
        this.productId = productId;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public BigDecimal getUnitPrice() {
        return unitPrice;
    }
    public void setUnitPrice(BigDecimal unitPrice) {
        this.unitPrice = unitPrice;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public Product() {
        super();
    }

    public Product(String productId, String name, BigDecimal unitPrice) {
      this.productId = productId;
      this.name = name;
      this.unitPrice = unitPrice;
    }

    public String toString() {
      return "Product [productId=" + productId + ", name=" + name + "]";
    }

}

ProductRepository.java

//interface

package com.packt.webstore.domain.repository;

import java.util.List;

import com.packt.webstore.domain.Product;

public interface ProductRepository {
  List<Product>getAllProducts();
}

InMemoryProductRepository.java

package com.packt.webstore.domain.repository.impl;

import java.math.BigDecimal;
import java.util.ArrayList;
import java.util.List;

import org.springframework.stereotype.Repository;

import com.packt.webstore.domain.Product;
import com.packt.webstore.domain.repository.ProductRepository;
@Repository
public class InMemoryProductRepository implements ProductRepository {
  private List <Product> listOfProducts=new ArrayList<Product>();

  public InMemoryProductRepository(){

      Product iphone=new Product("P1234","iPhone5s",new BigDecimal(500));
    listOfProducts.add(iphone);
  }
  public List<Product> getAllProducts() {
        // TODO Auto-generated method stub
        return listOfProducts;
    }

}

MVC-disaptcher-servlet.xml中

<?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-3.0.xsd
    http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">

  <context:annotation-config/>
    <context:component-scan base-package="com.mkyong.common.controller" />

    <bean
          class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix">
            <value>/WEB-INF/pages/</value>
        </property>
        <property name="suffix">
            <value>.jsp</value>
        </property>
    </bean>

</beans>

Answer 1

根據堆棧跟蹤，它無法autowire連接控制器內部的repository ，因為您沒有將其包括在組件掃描中。

將spring xml文件中的組件掃描行更改為以下內容。

<context:component-scan base-package="com.mkyong.common.controller,com.packt.webstore.domain.repository" />

Answer 2

你需要換線

  <context:component-scan base-package="com.mkyong.common.controller" />

至

  <context:component-scan base-package="com.packt.webstore.domain" />

因為您的組件在該軟件包中。