java Spring - 自动装配依赖项的注入失败
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时间：2020-11-02 14:39:59 来源:igfitidea点击:
Spring - Injection of autowired dependencies failed
提问by kaustubh sinha
The following error appears in the server :
服务器中出现以下错误：
SEVERE: Context initialization failed
严重：上下文初始化失败
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.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
Here is the code:
这是代码：
ProductController.java
产品控制器.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
产品.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
产品库.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
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
mvc-disaptcher-servlet.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-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>
回答by RE350
As per the stack trace,It is unable to autowirethe repositoryinside controller,because you have not included it in component scan.
由于每个堆栈跟踪，它是无法autowire在repository内部控制，因为你没有在组件扫描包含它。
Change your component scan line in spring xml file to below.
将 spring xml 文件中的组件扫描线更改为以下内容。
<context:component-scan base-package="com.mkyong.common.controller,com.packt.webstore.domain.repository" />
回答by Alexander
You need to change the line
你需要改变行
<context:component-scan base-package="com.mkyong.common.controller" />
to
到
<context:component-scan base-package="com.packt.webstore.domain" />
since your Components are in that package.
因为您的组件在该包中。
