创建名称为“projectController”的 bean 时出错：通过字段“服务”表达的依赖关系不满足；

Question

我使用下面的配置和代码来创建一个spring boot应用。

pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<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">
    <parent>
        <artifactId>jeecg-boot-parent</artifactId>
        <groupId>org.jeecgframework.boot</groupId>
        <version>2.3.0</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>my-pm-project</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.jeecgframework.boot</groupId>
            <artifactId>jeecg-system-cloud-api</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba.cloud</groupId>
            <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
        </dependency>
        <dependency>
            <groupId>org.jeecgframework.boot</groupId>
            <artifactId>jeecg-boot-base-common</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
    </dependencies>
</project>

控制器：

package cn.my.pm.project.controller;

import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.jeecg.common.api.vo.Result;
import org.jeecg.common.system.query.QueryGenerator;
import org.jeecg.common.util.oConvertUtils;
import cn.my.pm.project.entity.Project;
import cn.my.pm.project.service.IProjectService;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import lombok.extern.slf4j.Slf4j;
import org.jeecg.common.system.base.controller.JeecgController;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.servlet.ModelAndView;
import com.alibaba.fastjson.JSON;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.jeecg.common.aspect.annotation.AutoLog;


@RestController
@RequestMapping("/project/project")
@Slf4j
public class ProjectController extends JeecgController<Project, IProjectService> {
    @Autowired
    private IProjectService projectService;
    

    @GetMapping(value = "/list")
    public Result<?> queryPageList(Project project,
                                   @RequestParam(name="pageNo", defaultValue="1") Integer pageNo,
                                   @RequestParam(name="pageSize", defaultValue="10") Integer pageSize,
                                   HttpServletRequest req) {
        QueryWrapper<Project> queryWrapper = QueryGenerator.initQueryWrapper(project, req.getParameterMap());
        Page<Project> page = new Page<Project>(pageNo, pageSize);
        IPage<Project> pageList = projectService.page(page, queryWrapper);
        return Result.OK(pageList);
    }
    

    @PostMapping(value = "/add")
    public Result<?> add(@RequestBody Project project) {
        projectService.save(project);
        return Result.OK("add！");
    }
    

    @PutMapping(value = "/edit")
    public Result<?> edit(@RequestBody Project project) {
        projectService.updateById(project);
        return Result.OK("edit!");
    }
    

    @DeleteMapping(value = "/delete")
    public Result<?> delete(@RequestParam(name="id",required=true) String id) {
        projectService.removeById(id);
        return Result.OK("delete!");
    }
    

    @DeleteMapping(value = "/deleteBatch")
    public Result<?> deleteBatch(@RequestParam(name="ids",required=true) String ids) {
        this.projectService.removeByIds(Arrays.asList(ids.split(",")));
        return Result.OK("batch delete!");
    }
    
    
    @GetMapping(value = "/queryById")
    public Result<?> queryById(@RequestParam(name="id",required=true) String id) {
        Project project = projectService.getById(id);
        if(project==null) {
            return Result.error("not found");
        }
        return Result.OK(project);
    }


}

服务：

package cn.my.pm.project.service;

import cn.my.pm.project.entity.Project;
import com.baomidou.mybatisplus.extension.service.IService;

public interface IProjectService extends IService<Project> {

}

ServiceImpl：

package cn.my.pm.project.service.impl;

import cn.my.pm.project.entity.Project;
import cn.my.pm.project.mapper.ProjectMapper;
import cn.my.pm.project.service.IProjectService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;

@Service
@Slf4j
public class ProjectServiceImpl extends ServiceImpl<ProjectMapper, Project> implements IProjectService {

}

映射器：

package cn.my.pm.project.mapper;

import java.util.List;
import org.apache.ibatis.annotations.Param;
import cn.my.pm.project.entity.Project;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.springframework.stereotype.Service;

public interface ProjectMapper extends BaseMapper<Project> {

}

ProjectMapper.xml：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.my.pm.project.mapper.ProjectMapper">

</mapper>

实体：

package cn.my.pm.project.entity;

import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.util.Date;
import java.math.BigDecimal;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import com.fasterxml.jackson.annotation.JsonFormat;
import org.springframework.format.annotation.DateTimeFormat;
import org.jeecgframework.poi.excel.annotation.Excel;
import org.jeecg.common.aspect.annotation.Dict;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.EqualsAndHashCode;
import lombok.experimental.Accessors;

@Data
@TableName("my_info")

public class Project implements Serializable {
    private static final long serialVersionUID = 1L;
    private java.lang.String id;
    private java.lang.String myName;
    private java.lang.String myType;
    private java.lang.String myType;
    private java.lang.String myManager;
    private java.lang.String myInfo;
    private java.lang.String myDetails;
    private java.lang.String myImage;

}

应用程序：

package cn.my;

import org.apache.shiro.spring.boot.autoconfigure.ShiroAnnotationProcessorAutoConfiguration;
import org.apache.shiro.spring.boot.autoconfigure.ShiroAutoConfiguration;
import org.apache.shiro.spring.boot.autoconfigure.ShiroBeanAutoConfiguration;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication(exclude = {ShiroAnnotationProcessorAutoConfiguration.class, ShiroAutoConfiguration.class, ShiroBeanAutoConfiguration.class})
@EnableDiscoveryClient
@EnableFeignClients
public class ProjectApplication {

    public static void main(String[] args) {
        SpringApplication.run(ProjectApplication.class, args);
    }
}

但是当我运行应用程序时，错误消息是：

ERROR org.springframework.boot.SpringApplication:858 - Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'projectController': Unsatisfied dependency expressed through field 'service'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'projectServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'cn.my.pm.project.mapper.ProjectMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1395)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:849)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248)
    at cn.my.ProjectApplication.main(ProjectApplication.java:18)
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'projectServiceImpl': Unsatisfied dependency expressed through field 'baseMapper'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'cn.my.pm.project.mapper.ProjectMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1395)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1247)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    ... 19 common frames omitted
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'cn.my.pm.project.mapper.ProjectMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1654)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1213)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1167)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    ... 32 common frames omitted
Disconnected from the target VM, address: '127.0.0.1:64977', transport: 'socket'

如何解决？

Answer 1

Spring 的抱怨是您没有定义类型为ProjectMapper 的Bean，它表示它需要满足Autowire 请求。查看您的代码，我没有在您在这里向我们展示的内容中看到此类 Bean 的定义。

我猜问题的确切点是隐藏的，因为您没有向我们展示ServiceImpl 类的定义。我的猜测是，实际的参考是 Spring 试图连接的地方。显然，字段名称是baseMapper。

Answer 2

Spring 似乎没有找到 Mapper。 试试

 @Mapper
 public interface ProjectMapper extends BaseMapper<Project> {

 }

或者

@SpringBootApplication(exclude = {ShiroAnnotationProcessorAutoConfiguration.class, 
ShiroAutoConfiguration.class, ShiroBeanAutoConfiguration.class})
@EnableDiscoveryClient
@EnableFeignClients
@MapperScan(basePackage="cn.my.pm.project.mapper.*")
public class ProjectApplication {

public static void main(String[] args) {
    SpringApplication.run(ProjectApplication.class, args);
}

}

Answer 3

原因是包没有加上@MapperScan。

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@MapperScan(value={"org.abc.modules.**.mapper*", "cn.my.pm.**.mapper*"})
public class MybatisPlusConfig {
……
}

那么就没有错误了。