Question

下图是我的项目结构。 project structure

父项目是demo-mybatis子模块是mybatis-dao，demo-service。下面是demo-mybatis pom.xml：

4.0.0 绒球扁豆岛演示服务演示mybatis应用 org.springframework.boot 弹簧启动启动器父母 2.3.2发行 com.example my鼠 0.0.1-快照 my鼠 Spring Boot的演示项目

<properties>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-jdbc</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
        <exclusions>
            <exclusion>
                <groupId>org.junit.vintage</groupId>
                <artifactId>junit-vintage-engine</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid-spring-boot-starter</artifactId>
        <version>1.1.10</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis.spring.boot</groupId>
        <artifactId>mybatis-spring-boot-starter</artifactId>
        <version>1.3.2</version>
    </dependency>
</dependencies>

mybatis-dao UserMapper.java接口： ```

@Repository
public interface UserMapper {
    List selectByName(String name);
    int insert(User user);
    void update(User user);
    void delete(Long id);
    User verify(User user);
    List select();
}

demo-service UserServiceImpl.java class :

@Service
public class UserServiceImpl implements UserService {

    @Resource
    private UserMapper userMapper;

    @Override
    public List selectByName(String name) {
        return null;
    }

    @Override
    public int insert(User user) {
        return 0;
    }
}

run application class :
``` @SpringBootApplication
@ComponentScan(basePackages = {"com.example","com.wjs"})
@EnableCaching(proxyTargetClass = true)
@MapperScan(basePackages = {"com.wjs.model.dao"})
public class DemoMybatisAppApplication {

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

}

application.properties：

server.port=8002
spring.datasource.url=jdbc:mysql://localhost:3306/demo?useSSL=false
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.application.name=demo-mybatis
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
mybatis.mapper-locations=classpath:mapper/*.xml
mybatis.type-aliases-package=com.wjs.model.entity

以下总是例外：我找不到原因？我尝试这个：

    @Resource
    private UserMapper userMapper;

问题是：

  nested exception is org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'userMapper' is expected to be of type 'com.wjs.model.dao.UserMapper' but was actually of type 'com.sun.proxy.$Proxy55'

和

    @Autowired
    private UserMapper userMapper;

问题是：

 No qualifying bean of type 'com.wjs.model.dao.UserMapper' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}

我疯了

Answer 1

@Mapper 公共接口UserMapper

说明：

无法将bean'userMapper'作为'com.example.mapper.UserMapper'注入，因为它是实现以下目的的JDK动态代理：

动作：

通过在@EnableAsync和/或@EnableCaching上设置proxyTargetClass = true，考虑将bean作为其接口之一注入或强制使用基于CGLib的代理。

springboot + mybatis多模块项目专家

1 个答案: