构建电子地图网站——02 搭建开发平台：SpringBoot+MyBatis+PostgreSQL

2022-11-15 10:19:42 # Springboot # GIS # PostSQL

1 完成工程搭建及项目结构

需要添加的依赖：
- Spring Boot DevTools：热部署，修改内容，工程自动重启
Lombok：打日志、注解工具，调试代码用
- Spring Configuration Processor：引入配置的工具
Spring Web Starter：web工程启动工具
- Thymeleaf：整合前端用的
JDBC API：连数据库的引擎
- Mybatis Framwork：Mybatis框架

PostgreSQL Driver：pg库引擎

<!--jdbc-->
  <dependency>
    <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
  <!--thymeleaf-->
  <dependency>
      <groupId>org.springframework.boot</groupId>
	    <artifactId>spring-boot-starter-thymeleaf</artifactId>
  </dependency>
  <!--web-->
  <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <!--mybatis-->
  <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.2.2</version>
  </dependency>
  <!--devtools-->
  <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-devtools</artifactId>
      <scope>runtime</scope>
      <optional>true</optional>
  </dependency>
  <!--postgresql-->
  <dependency>
      <groupId>org.postgresql</groupId>
      <artifactId>postgresql</artifactId>
      <version>42.2.2</version>
      <!--			<scope>runtime</scope>-->
  </dependency>
  <!--configuration-->
  <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-configuration-processor</artifactId>
      <optional>true</optional>
  </dependency>
  <!--lombok-->
  <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.8</version>
      <optional>true</optional>
  </dependency>

新增的一些依赖：

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-lang3</artifactId>
    <version>3.4</version>
</dependency>
<!--解析json的-->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-joda</artifactId>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.module</groupId>
    <artifactId>jackson-module-parameter-names</artifactId>
</dependency>
<!-- 分页插件 -->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.2.5</version>
</dependency>
<!-- alibaba的druid数据库连接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.9</version>
</dependency>
<!-- 解析几何geometry对象用的-->
<dependency>
    <groupId>com.vividsolutions</groupId>
    <artifactId>jts</artifactId>
    <version>1.13</version>
</dependency>

完善工程结构

java.com.cc：
- controller
  - MapController
- dao
  - MapDao
- model
  - PointModel
- service
  - impl
    - MapServiceImpl
  - MapService
resource：
- mapper
  - MapwebMapper.xml
- application.yml
package（包）的命名都需要小写；接口和类的命名要符号驼峰规则
点击小齿轮，取消勾选Compack Middle Packages，勾选上的话，会把空的package给折叠了

2 连接数据库

application.yml

server:
  port: 8080

 # 数据库配置
spring:
  main:
    allow-circular-references: true
  datasource:
    initialize: flase
    url: jdbc:postgresql://localhost:5432/postgres
    username: postgres
    password: 123456
    # alibaba数据连接池
    type: com.alibaba.druid.pool.DruidDataSource
    # postgresql驱动
    driver-class-name: org.postgresql.Driver
    druid:
      # 初始化连接大小
      initial-size: 8
      # 最小空闲连接数
      min-idle: 5
      # 最大连接数
      max-active: 10
      # 查询超时时间
      query-timeout: 6000
      # 事务查询超时时间
      transaction-query-timeout: 6000
      # 关闭空闲连接超时时间
      remove-abandoned-timeout: 1800
      filter: stat,config

mybatis:
  # sql映射文件
  mapper-locations: classpath:mapper/*.xml
  # 定义别名包
  type-aliases-package: com.cc.model

3 增删改查

3.1 DAO(Mapper)层

MapDao

@Service
public interface MapDao {
List<PointModel> getCntyPoint(@Param("gId") Integer gId);
int insertCntyPoint(PointModel pointModel);
int updateCntyPoint(PointModel pointModel);
int deleteCntyPoint(@Param("gId") Integer gId);
}

3.2 Mapper配置

MapwebMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//http://mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.cc.dao.MapDao" >
    <resultMap id="pointModelResult" type="com.cc.model.PointModel">
        <result property="gId" column="gid" jdbcType="BIGINT"/>
        <result property="nameCh" column="name_ch" jdbcType="VARCHAR"/>
    </resultMap>
    <sql id="BASE_TABLE">
        v6_time_cnty_pts_utf_wgs84
    </sql>

    <sql id="BASE_COLUMN">
        gid,name_ch
    </sql>

    <!--查询-->
    <select id="getCntyPoint" resultMap="pointModelResult">
        SELECT
        <include refid="BASE_COLUMN"></include>
        FROM
        <include refid="BASE_TABLE"/>
        WHERE gid=#{gId}
    </select>

    <!--插入-->
    <insert id="insertCntyPoint" parameterType="com.cc.model.PointModel">
        INSERT INTO
        <include refid="BASE_TABLE"/>
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="gId != null">
                gid,
            </if>
            <if test="nameCh != null">
                name_ch,
            </if>
        </trim>
        <trim prefix="VALUES(" suffix=")" suffixOverrides=",">
            <if test="gId != null">
                #{gId, jdbcType=BIGINT},
            </if>
            <if test="nameCh != null">
                #{nameCh, jdbcType=VARCHAR},
            </if>
        </trim>
    </insert>

    <!--更新-->
    <update id="updateCntyPoint" parameterType="com.cc.model.PointModel">
        UPDATE
        <include refid="BASE_TABLE"/>
        SET
        name_ch=#{nameCh}
        WHERE
        gid=#{gId}
    </update>

    <!--删除-->
    <delete id="deleteCntyPoint" parameterType="com.cc.model.PointModel">
        DELETE FROM
        <include refid="BASE_TABLE"/>
        WHERE
        gid=#{gId}
    </delete>
</mapper>

application.yml

1
2
3

mybatis:
  # sql映射文件
  mapper-locations: classpath:mapper/*.xml

3.3 Service层

接口——MapService

public interface MapService {
List<PointModel> getCntyPointByGid(Integer gId);
int addCntyPoint(PointModel pointModel);
int modifyCntyPoint(PointModel pointModel);
int removeCntyPoint(Integer gId);
}

实现类——MapServiceImpl

@Service
public class MapServiceImpl implements MapService {
@Autowired
private MapDao mapDao;
@Override
public List<PointModel> getCntyPointByGid(Integer gId){
return mapDao.getCntyPoint(gId);
}
@Override
public int addCntyPoint(PointModel pointModel){
return mapDao.insertCntyPoint(pointModel);
}
@Override
public int modifyCntyPoint(PointModel pointModel){
return mapDao.updateCntyPoint(pointModel);
}
@Override
public int removeCntyPoint(Integer gId){
return mapDao.deleteCntyPoint(gId);
}
}

3.4 Controller层

MapController

@Controller
@RequestMapping(value = "/history")
public class MapController {
@Autowired
private MapService mapService;
@ResponseBody
@GetMapping("/pointmodel")
public PointModel getPoint(@RequestParam("gid") Integer gId){
return mapService.getCntyPointByGid(gId).get(0);
}
@ResponseBody
@PostMapping("/add")
public int addPoint(PointModel pointModel){
return mapService.addCntyPoint(pointModel);
}
@ResponseBody
@PostMapping("/modify")
public int update(PointModel pointModel){
return mapService.modifyCntyPoint(pointModel);
}
@ResponseBody
@GetMapping("/remove")
public int removetPoint(@RequestParam("gid") Integer gId){
return mapService.removeCntyPoint(gId);
}
}

3.5 测试

可以用工具测试，也可以用浏览器直接访问，测试工具Postman用得较多，但是现在好像不能直接在浏览器中使用，但有一个Postwoman 扩展也差不多！

查（直接访问）

1	http://localhost:8080/history/pointmodel?gid=1

增（POST请求）

1	http://localhost:8080/history/add?gid=14354&nameCh=test

改（POST请求）

1	http://localhost:8080/history/modify?gid=14354&nameCh=test01

删（GET请求）

1	http://localhost:8080/history/remove?gid=1435

3.6 上传代码至GitHub

最简便的方法就是，可以直接通过IDEA上传代码至GitHub仓库。“VCS”==>”Share Project on GitHub”

4 报错

报错1：

循环依赖问题：

Relying upon circular references is discouraged and they are prohibited by default. Update your application to remove the dependency cycle between beans. As a last resort, it may be possible to break the cycle automatically by setting spring.main.allow-circular-references to true.

解决办法：在yml配置文件中新增以下语句

1
2
3

spring:
  main:
    allow-circular-references: true

参考链接：解决循环依赖BUG。Relying upon circular references is discouraged and they are prohibited by default._去海边整点浪漫的博客-CSDN博客

报错2：

Invalid bound statement——无效绑定，是mybatis中常见的一个异常。

1	Invalid bound statement (not found): com.cc.dao.MapDao.getCntyPoint] with root cause

问题实质：mapper接口（dao层）和xml没有绑定成功，也叫做与xml文件没有映射！
解决办法：在yml配置文件中，发现映射xml的路径打错了，多打了一个s
一些Tips：
- 接口与xml的绑定原理：mapper接口并没有实现类，所以框架会通过JDK动态代理模式获取接口的代理实现类，进而根据接口全限定类名+id去一一绑定xml中的sql
- mapper文件要和.xml的目录结构一样
- 可以通过target目录查看mapper是否成功加载

参考链接：mybatis常见异常：Invalid bound statement (not found): com.ruoyi.news.mapper.RuoyiNewsMapper.selectRuoyiNe_hexz0407的博客-CSDN博客

三步教你解决Invalid bound statement (not found): com.xxx.dao.xxxDao.selectByxx错误!!!!很简单_倩女有文的博客-CSDN博客

2022-11-15 10:19:42 # Springboot # GIS # PostSQL