【PostGIS】在Java中操作postgis——使用springboot+Maven+mybatis框架

前言：
PostgreSQL15+对应PostGIS安装教程及空间数据可视化
空间数据库-常用空间函数

完成PostGIS的安装与配置后，让我们来写一个Java操作postgis数据库的demo吧~

使用工具：

Navicat
IDEA

一、PostGIS数据库准备

在Navicat中新建一个postgreSQL的连接，并新建一个名为"postdemo"的数据库：
→
在数据库中创建postgis扩展，并创建 bou2_4p 表（执行以下sql语句）：

-- 创建postgis扩展
CREATE EXTENSION postgis;

-- 创建表 bou2_4p
CREATE TABLE bou2_4p (
  gid SERIAL PRIMARY KEY,
	area float8,
	perimeter float8,
	bou2_4m_ float8,
	bou2_4m_id float8,
	adcode93 INT,
	adcode99 INT,
  name VARCHAR(20),
  geom geometry(MultiPolygon, 4326)
);
INSERT INTO bou2_4p (area, perimeter, bou2_4m_, bou2_4m_id, adcode93, adcode99, name, geom) VALUES (0.0, 0.018, 923.0, 3109.0, 810000, 810000, '香港特别行政区', ST_GeomFromText('MULTIPOLYGON(((114.286201477051 22.1847763061523,114.28434753418 22.1850299835205,114.284927368164 22.187816619873,114.287582397461 22.1907157897949,114.290313720703 22.1892375946045,114.287910461426 22.1863689422607,114.286201477051 22.1847763061523)))', 4326));
INSERT INTO bou2_4p (area, perimeter, bou2_4m_, bou2_4m_id, adcode93, adcode99, name, geom) VALUES (0.0, 0.014, 924.0, 3112.0, 810000, 810000, '香港特别行政区', ST_GeomFromText('MULTIPOLYGON(((114.303497314453 22.1849155426025,114.304130554199 22.1863536834717,114.305946350098 22.1868076324463,114.308296203613 22.1860828399658,114.308296203613 22.1850547790527,114.307823181152 22.1833896636963,114.305519104004 22.1828384399414,114.304168701172 22.1835269927979,114.303497314453 22.1849155426025)))', 4326));

二、构建项目

在IDEA中创建一个Maven项目，并在pom.xml文件中引入相关依赖：

<dependencies>
        <!-- Mybatis核心 -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.7</version>
        </dependency>
        <!-- junit测试 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>

        <!-- pg驱动 -->
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <version>42.3.8</version>
        </dependency>
        <!-- postgis -->
        <dependency>
            <groupId>net.postgis</groupId>
            <artifactId>postgis-jdbc</artifactId>
            <version>2.5.0</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.30</version>
        </dependency>
        <!--slf4j依赖-->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-api</artifactId>
            <version>1.7.32</version>
        </dependency>
        <!-- logback 依赖 -->
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-classic</artifactId>
            <version>1.2.3</version>
        </dependency>
    </dependencies>

mybatis全局配置xml文件（其中数据库的名字，用户名和密码，以及SQL映射文件路径改成自己的）：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!--声明使用的环境 default是引用环境的id，表示当前所使用的环境 -->
    <environments default="default">
        <environment id="default">
            <!--使用原生JDBC事务  -->
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="org.postgresql.Driver"/>
                <property name="url" value="jdbc:postgresql://localhost:5432/postdemo"/>
                <property name="username" value="postgres"/>
                <property name="password" value="123456"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/postgis/demo/mapper/demoMapper.xml" />
    </mappers>
</configuration>

创建实体类 bou2_4p：

java">package com.postgis.demo.pojo;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@AllArgsConstructor
@NoArgsConstructor
@Data
public class bou2_4p {
    private int gid;
    private double area;
    private double perimeter;
    private double bou2_4m_;
    private double bou2_4m_id;
    private int adcode93;
    private int adcode99;
    private String name;
    private String geom;
}

创建mapper接口，SQL映射文件：

java">package com.postgis.demo.mapper;

import com.postgis.demo.pojo.bou2_4p;

import java.util.List;

public interface demoMapper {
    List<bou2_4p> selAll();
}

<?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.postgis.demo.mapper.demoMapper">
    <select id="selAll" resultType="com.postgis.demo.pojo.bou2_4p">
        select gid,area,perimeter,bou2_4m_,bou2_4m_id,adcode93,adcode99,name,ST_AsText(geom) as geom from bou2_4p
    </select>
</mapper>

创建测试类进行查询测试：

java">package com.postgis.demo.test;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.postgis.demo.pojo.bou2_4p;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

public class Test {
    public static void main(String[] args) throws IOException {
        Logger logger = LoggerFactory.getLogger(Test.class);
        InputStream is = Resources.getResourceAsStream("mybatis-config.xml");
        //使用工厂设计模式
        SqlSessionFactory factory=new SqlSessionFactoryBuilder().build(is);
        //生产SqlSession
        SqlSession  session=factory.openSession();
        logger.info("查询数据：");
        //方法名+包名
        List<bou2_4p> selectList = session.selectList("com.postgis.demo.mapper.demoMapper.selAll");
        for(bou2_4p u:selectList){
            System.out.println(u);
        }
        session.close();
    }
}