package com.bolingcavalry.relatedoperation;

import com.alibaba.druid.pool.DruidDataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class DruidConfig {

    private static final Logger logger = LoggerFactory.getLogger(DruidConfig.class);

    @Value("${spring.datasource.url}")
    private String dbUrl;
    @Value("${spring.datasource.username}")
    private String username;
    @Value("${spring.datasource.password}")
    private String password;
    @Value("${spring.datasource.driver-class-name}")
    private String driverClassName;
    @Value("${spring.datasource.druid.initial-size}")
    private int initialSize;
    @Value("${spring.datasource.druid.max-active}")
    private int maxActive;
    @Value("${spring.datasource.druid.min-idle}")
    private int minIdle;
    @Value("${spring.datasource.druid.max-wait}")
    private int maxWait;
    @Value("${spring.datasource.druid.pool-prepared-statements}")
    private boolean poolPreparedStatements;
    @Value("${spring.datasource.druid.max-pool-prepared-statement-per-connection-size}")
    private int maxPoolPreparedStatementPerConnectionSize;
    @Value("${spring.datasource.druid.time-between-eviction-runs-millis}")
    private int timeBetweenEvictionRunsMillis;
    @Value("${spring.datasource.druid.min-evictable-idle-time-millis}")
    private int minEvictableIdleTimeMillis;
    @Value("${spring.datasource.druid.max-evictable-idle-time-millis}")
    private int maxEvictableIdleTimeMillis;
    @Value("${spring.datasource.druid.validation-query}")
    private String validationQuery;
    @Value("${spring.datasource.druid.test-while-idle}")
    private boolean testWhileIdle;
    @Value("${spring.datasource.druid.test-on-borrow}")
    private boolean testOnBorrow;
    @Value("${spring.datasource.druid.test-on-return}")
    private boolean testOnReturn;
    @Value("${spring.datasource.druid.filters}")
    private String filters;
    @Value("{spring.datasource.druid.connection-properties}")
    private String connectionProperties;

    /**
     * Druid 连接池配置
     */
    @Bean
    public DruidDataSource dataSource() {
        DruidDataSource datasource = new DruidDataSource();
        datasource.setUrl(dbUrl);
        datasource.setUsername(username);
        datasource.setPassword(password);
        datasource.setDriverClassName(driverClassName);
        datasource.setInitialSize(initialSize);
        datasource.setMinIdle(minIdle);
        datasource.setMaxActive(maxActive);
        datasource.setMaxWait(maxWait);
        datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
        datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        datasource.setMaxEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
        datasource.setValidationQuery(validationQuery);
        datasource.setTestWhileIdle(testWhileIdle);
        datasource.setTestOnBorrow(testOnBorrow);
        datasource.setTestOnReturn(testOnReturn);
        datasource.setPoolPreparedStatements(poolPreparedStatements);
        datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
        try {
            datasource.setFilters(filters);
        } catch (Exception e) {
            logger.error("druid configuration initialization filter", e);
        }
        datasource.setConnectionProperties(connectionProperties);
        return datasource;
    }

}

6. swagger配置类：

package com.bolingcavalry.relatedoperation;

import springfox.documentation.service.Contact;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Tag;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

@Configuration
@EnableSwagger2
public class SwaggerConfig {

    @Bean
    public Docket createRestApi() {
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())
                .tags(new Tag("UserController", "用户服务"), new Tag("LogController", "日志服务"))
                .select()
                // 当前包路径
                .apis(RequestHandlerSelectors.basePackage("com.bolingcavalry.relatedoperation.controller"))
                .paths(PathSelectors.any())
                .build();
    }

    //构建 api文档的详细信息函数,注意这里的注解引用的是哪个
    private ApiInfo apiInfo() {
        return new ApiInfoBuilder()
                //页面标题
                .title("MyBatis CURD操作")
                //创建人
                .contact(new Contact("程序员欣宸", "https://github.com/zq2599/blog_demos", "zq2599@gmail.com"))
                //版本号
                .version("1.0")
                //描述
                .description("API 描述")
                .build();
    }
}

package com.bolingcavalry.relatedoperation;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.bolingcavalry.relatedoperation.mapper")
public class RelatedOperationApplication {

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

}

package com.bolingcavalry.relatedoperation.entity;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@ApiModel(description = "用户实体类")
public class User {

    @ApiModelProperty(value = "用户ID")
    private Integer id;

    @ApiModelProperty(value = "用户名", required = true)
    private String name;

    @ApiModelProperty(value = "用户地址", required = false)
    private Integer age;
}

package com.bolingcavalry.relatedoperation.entity;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.sql.Date;

@Data
@NoArgsConstructor
@ApiModel(description = "日志实体类")
public class Log {
    @ApiModelProperty(value = "日志ID")
    private Integer id;

    @ApiModelProperty(value = "用户ID")
    private Integer userId;

    @ApiModelProperty(value = "日志内容")
    private String action;

    @ApiModelProperty(value = "创建时间")
    private Date createTime;
}

package com.bolingcavalry.relatedoperation.entity;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@ApiModel(description = "日志实体类(含用户表的字段)")
public class LogExtend extends Log {

    @ApiModelProperty(value = "用户名")
    private String userName;
}

<?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="com.bolingcavalry.relatedoperation.mapper.LogMapper">

    <!--联表查询，返回log对象，该对象有个userName字段，值是user表的user_name字段-->
    <select  parameterType="int" resultMap="logExtendResultMap">
        select l.id as id,
               l.user_id as user_id,
               l.action as action,
               l.create_time as create_time,
               u.name as user_name
        from log as l
                 left join user as u
                           on l.user_id = u.id
        where l.id = #{id}
    </select>

    <resultMap  type="logExtend">
        <id property="id" column="id"/>
        <result column="user_id" jdbcType="INTEGER" property="userId"/>
        <result column="action" jdbcType="VARCHAR" property="action"/>
        <result column="create_time" jdbcType="TIMESTAMP" property="createTime"/>
        <result column="user_name" jdbcType="VARCHAR" property="userName"/>
    </resultMap>
</mapper>

package com.bolingcavalry.relatedoperation.mapper;

import com.bolingcavalry.relatedoperation.entity.LogAssociateUser;
import com.bolingcavalry.relatedoperation.entity.LogExtend;
import org.springframework.stereotype.Repository;

@Repository
public interface LogMapper {

    LogExtend oneObjectSel(int id);
}

package com.bolingcavalry.relatedoperation.service;

import com.bolingcavalry.relatedoperation.entity.LogAssociateUser;
import com.bolingcavalry.relatedoperation.entity.LogExtend;
import com.bolingcavalry.relatedoperation.mapper.LogMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class LogService {
    @Autowired
    LogMapper logMapper;

    public LogExtend oneObjectSel(int id){
        return logMapper.oneObjectSel(id);
    }
}

@RestController
@RequestMapping("/log")
@Api(tags = {"LogController"})
public class LogController {
    @Autowired
    private LogService logService;

    @ApiOperation(value = "根据ID查找日志记录，带userName字段，该字段通过联表查询实现", notes="根据ID查找日志记录，带userName字段，该字段通过联表查询实现")
    @ApiImplicitParam(name = "id", value = "日志ID", paramType = "path", required = true, dataType = "Integer")
    @RequestMapping(value = "/aggregate/{id}", method = RequestMethod.GET)
    public LogExtend oneObjectSel(@PathVariable int id){
        return logService.oneObjectSel(id);
    }

package com.bolingcavalry.relatedoperation.controller;

import lombok.extern.slf4j.Slf4j;
import org.junit.jupiter.api.*;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.http.MediaType;
import org.springframework.test.context.ActiveProfiles;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;

import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.print;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@SpringBootTest
@DisplayName("Web接口的单元测试")
@AutoConfigureMockMvc
@ActiveProfiles("test")
@Slf4j
public class ControllerTest {
    /**
     * 查询方式：联表
     */
    final static String SEARCH_TYPE_LEFT_JOIN = "leftjoin";

    /**
     * 查询方式：嵌套
     */
    final static String SEARCH_TYPE_NESTED = "nested";

    final static int TEST_USER_ID = 3;

    final static String TEST_USER_NAME = "tom";

    @Autowired MockMvc mvc;

    @Nested
    @TestMethodOrder(MethodOrderer.OrderAnnotation.class)
    @DisplayName("用户服务")
    class User {
    
    }
    
    @Nested
    @TestMethodOrder(MethodOrderer.OrderAnnotation.class)
    @DisplayName("日志服务")
    class Log {
        final static int TEST_LOG_ID = 5;

        @Test
        @DisplayName("通过日志ID获取日志信息,带userName字段，该字段通过联表查询实现")
        @Order(1)
        void oneObjectSel() throws Exception {
            mvc.perform(MockMvcRequestBuilders.get("/log/aggregate/" + TEST_LOG_ID)
                    .accept(MediaType.APPLICATION_JSON))
                    .andExpect(status().isOk())
                    .andExpect(jsonPath("$.id").value(TEST_LOG_ID))
                    .andExpect(jsonPath("$.userName").value(TEST_USER_NAME))
                    .andDo(print());
        }
    }
}

@Data
@NoArgsConstructor
@ApiModel(description = "日志实体类")
public class LogAssociateUser {
    @ApiModelProperty(value = "日志ID")
    private Integer id;

    @ApiModelProperty(value = "用户对象")
    private User user;

    @ApiModelProperty(value = "日志内容")
    private String action;

    @ApiModelProperty(value = "创建时间")
    private Date createTime;
}

@Data
@NoArgsConstructor
@ApiModel(description = "日志实体类")
public class LogAssociateUser {
    @ApiModelProperty(value = "日志ID")
    private Integer id;

    @ApiModelProperty(value = "用户对象")
    private User user;

    @ApiModelProperty(value = "日志内容")
    private String action;

    @ApiModelProperty(value = "创建时间")
    private Date createTime;
}

    <!--联表查询，返回log对象，它的成员变量中有user对象-->
    <select  parameterType="int" resultMap="leftJoinResultMap">
        select l.id as log_id,
               l.action as log_action,
               l.create_time as log_create_time,
               u.id as user_id,
               u.name as user_name,
               u.age as user_age
        from log as l
               left join user as u
               on l.user_id = u.id
        where l.id = #{id}
    </select>

    <resultMap  type="LogAssociateUser">
        <id property="id" column="log_id"/>

        <result  property="action" column="log_action" jdbcType="VARCHAR"/>

        <result property="createTime" column="log_create_time" jdbcType="TIMESTAMP" />

        <association property="user" javaType="User">
            <id property="id" column="user_id"/>
            <result property="name" column="user_name"/>
            <result property="age" column="user_age"/>
        </association>
    </resultMap>

    @ApiOperation(value = "根据ID查找日志记录，带用户对象，联表查询实现", notes="根据ID查找日志记录，带用户对象，联表查询实现")
    @ApiImplicitParam(name = "id", value = "日志ID", paramType = "path", required = true, dataType = "Integer")
    @RequestMapping(value = "/leftjoin/{id}", method = RequestMethod.GET)
    public LogAssociateUser leftJoinSel(@PathVariable int id){
        return logService.leftJoinSel(id);
    }

        /**
         * 通过日志ID获取日志信息有两种方式：联表和嵌套查询，
         * 从客户端来看，仅一部分path不同，因此将请求和检查封装到一个通用方法中，
         * 调用方法只需要指定不同的那一段path
         * @param subPath
         * @throws Exception
         */
        private void queryAndCheck(String subPath) throws Exception {
            String queryPath = "/log/" + subPath + "/" + TEST_LOG_ID;

            log.info("query path [{}]", queryPath);

            mvc.perform(MockMvcRequestBuilders.get(queryPath)
                    .accept(MediaType.APPLICATION_JSON))
                    .andExpect(status().isOk())
                    .andExpect(jsonPath("$.id").value(TEST_LOG_ID))
                    .andExpect(jsonPath("$.user.id").value(TEST_USER_ID))
                    .andDo(print());
        }

        @Test
        @DisplayName("通过日志ID获取日志信息（关联了用户），联表查询")
        @Order(2)
        void leftJoinSel() throws Exception {
            queryAndCheck(SEARCH_TYPE_LEFT_JOIN);
        }

    <!--嵌套-->
    <select  parameterType="int" resultMap="nestedResultMap">
        select
            l.id as log_id,
            l.user_id as log_user_id,
            l.action as log_action,
            l.create_time as log_create_time
        from mybatis.log as l
        where l.id = #{id}
    </select>

    <!-- association节点的select属性会触发嵌套查询-->
    <resultMap  type="LogAssociateUser">
        <!-- column属性中的log_id，来自前面查询时的"l.id as log_id" -->
        <id property="id" column="log_id"/>
        <!-- column属性中的log_action，来自前面查询时的"l.action as log_action" -->
        <result  property="action" column="log_action" jdbcType="VARCHAR"/>
        <!-- column属性中的log_create_time，来自前面查询时的"l.create_time as log_create_time" -->
        <result property="createTime" column="log_create_time" jdbcType="TIMESTAMP" />
        <!-- select属性，表示这里要执行嵌套查询，将log_user_id传给嵌套的查询 -->
        <association property="user" column="log_user_id" select="selectUserByUserId"></association>
    </resultMap>