SpringBoot中controller发送请求时提示Null

最近在学习springboot时，发现controller 发送请求，返回NullPointerException，检查了好几遍配置，也没有发现具体问题，具体如下：

1.Application

@EnableAutoConfiguration
@SpringBootApplication
@ComponentScan
@MapperScan("cn.no7player.mapper")
public class Application {
    private static Logger logger = Logger.getLogger(String.valueOf(Application.class));
    //DataSource配置
    @Bean
    @ConfigurationProperties(prefix="spring.datasource")
    public DataSource dataSource() {
        return new org.apache.tomcat.jdbc.pool.DataSource();
    }


    //提供SqlSeesion
    @Bean
    public SqlSessionFactory sqlSessionFactoryBean() throws Exception {

        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        sqlSessionFactoryBean.setDataSource(dataSource());

        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();

        sqlSessionFactoryBean.setMapperLocations(resolver.getResources("classpath:/mybatis/*.xml"));

        return sqlSessionFactoryBean.getObject();
    }

    @Bean
    public PlatformTransactionManager transactionManager() {
        return new DataSourceTransactionManager(dataSource());
    }


    /**
     * Start
     */
    public static void main(String[] args) {

            SpringApplication.run(Application.class, args);

        logger.info("SpringBoot Start Success");
    }

}

2.UserService

@Service
public class UserService {
  //  @Autowired
    private UserMapper userMapper;

    public User getUserInfo(){
        User user=userMapper.findUserInfo();
        //User user=null;
        return user;
    }

}

3.model

package cn.no7player.model;

import java.io.Serializable;

 
public class User implements Serializable {
    private String name;
    private Integer age;
    private String password;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

4.mapper

public interface UserMapper {
    public User findUserInfo();
}

5.mybatis的mapper.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.no7player.mapper.UserMapper">
  <select id="findUserInfo" resultType="cn.no7player.model.User">
    select name,  age,password from user;
  </select>
</mapper>

6.controller

@Controller
public class UserController {
  Logger logger = Logger.getLogger(String.valueOf(UserController.class));

    @Autowired
    private UserService userService;

    @RequestMapping("/getUserInfo")
    @ResponseBody
    public User getUserInfo() {

        User user = userService.getUserInfo();
        if(user!=null){
            System.out.println("user.getName():"+user.getName());
            logger.info("user.getAge():"+user.getAge());
        }
        return user;
    }
}

启动项目，发送post请求，控制台提示java.lang.NullPointerException: null
解决方法：检查注解，最后发现UserService中的UserMapper上少了个注解@Autowired，加上后问题得以解决。