Spitter不满意的依赖异常Spring MVC

Question

I starting in Spring MVC with the Book Spring in Action, I'm making the exercise of the chapter 5, with the Spitter application but I got the following error:

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'spittleController' defined in file [C:\\xampp\\htdocs.metadata.plugins\\org.eclipse.wst.server.core\\tmp1\\wtpwebapps\\spitter\\WEB-INF\\classes\\com\\spitter\\web\\SpittleController.class]: Unsatisfied dependency expressed through constructor argument with index 0 of type [com.spitter.data.SpittleRepository]: : No qualifying bean of type [com.spitter.data.SpittleRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.spitter.data.SpittleRepository] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {}

I got the project here in github: https://github.com/kevingcfcb88/spitter.git

I already do my research but nothing seems to work.

I'm using STS and Maven, this is the structure of the app:

Here is my pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>com.spitter.config</groupId>
<artifactId>spitter</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>

<name>spitter</name>
<url>http://maven.apache.org</url>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <springframework.version>4.1.5.RELEASE</springframework.version>
</properties>

<dependencies>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>3.8.1</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${springframework.version}</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>javax.servlet.jsp-api</artifactId>          
        <version>2.3.1</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.apache.commons/commons-lang3 -->
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.0</version>
    </dependency>

</dependencies>

<build>
    <pluginManagement>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.2</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.4</version>
                <configuration>
                    <warSourceDirectory>src/main/webapp</warSourceDirectory>
                    <warName>spitter</warName>
                    <failOnMissingWebXml>false</failOnMissingWebXml>
                </configuration>
            </plugin>
        </plugins>
    </pluginManagement>
    <finalName>spitter</finalName>
</build>

And my config files:

SpittrWebAppInitializer.java

 package com.spitter.config;

import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;

public class SpittrWebAppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer{

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[] { RootConfig.class };
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[] { WebConfig.class };
    }

    @Override
    protected String[] getServletMappings() {
        return new String[] { "/" };
    }

}

WebConfig.java

package com.spitter.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan("com.spitter.web")
public class WebConfig extends WebMvcConfigurerAdapter {

    @Bean
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

}

RootConfig.java

package com.spitter.config;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.ComponentScan.Filter;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;

@Configuration
@ComponentScan(basePackages = { "com.spitter.data" }, excludeFilters = {@Filter(type = FilterType.ANNOTATION, value = EnableWebMvc.class) })
public class RootConfig {

}

Answer 1

As @mh-dev explained, you need an implementation of SpittleRepository . Try adding this class and see if your code can run:

public class SpittleRepositoryImpl implements SpittleRepository {

  List <Spittle> findSpittles(long max, int count) {
    System.out.println("I need a real implementation! " 
      + "I received max as " + max + " and count as " + count + ".");
  }

}

I would suggest re-reading the relevant sections of the book to make sure you didn't miss anything.

Answer 2

You just need to add a repository implementation of SpittleRepository with @Repository in the header, because even though you have added implementation classes, spring IOC is unaware of actual dependency and the example in the book should have worked if you had put all the java files in the same package hierarchy with repository implementation.

@Repository
public class SpittleRepositoryDAO implements SpittleRepository {

    public SpittleRepositoryDAO() {

    }

    @Override
    public List<Spittle> findSpittles(long max, int count) {
        List<Spittle> spittles = new ArrayList<Spittle>();
        for (int i = 0; i < count; i++) {
            spittles.add(new Spittle("Spittle " + i, new Date()));
        }
        return spittles;
    }
}

Answer 3

I know this code. It used to give me serious headache 2 years ago. The eror is in the code OR the book itslef.

Go to the publishers site and download the updated sourcecode. here

or

https://www.manning.com/books/spring-in-action-fourth-edition

Answer 4

Here is the implementation of the repository:

package com.spitter.web;

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 org.springframework.web.bind.annotation.RequestMethod;

import com.spitter.data.SpittleRepository;

@Controller
@RequestMapping("/spittles")
public class SpittleController {

    private SpittleRepository spittleRepository;

    @Autowired
    public SpittleController(SpittleRepository spittleRepository) {
        this.spittleRepository = spittleRepository;
    }

    @RequestMapping(method = RequestMethod.GET)
    public String spittles(Model model) {
        model.addAttribute("spittleList", spittleRepository.findSpittles(Long.MAX_VALUE, 20));
        return "spittles";
    }

}

Answer 5

yep, the problem is that you need an implementation of SpittleRepository . Cause you can't have an interface as bean, you know. The scan component need at least one implementation of it and with the annotation @Component. That's it ;)