SpringBoot实现的查询数据库操作 (点击这里跳转到页面查看)
eclipse j2ee 2019、apache-maven-3.6.1、jdk1.8、Navicat for mysql 12、postman。
下载apache-maven-3.6.1压缩包,解压到某个文件夹,右键计算机-属性-高级系统设置-环境变量中新建MAVEN_HOME,设置值为maven解压的目录路径,编辑Path变量,新增%MAVEN_HOME%\bin。打开cmd.exe,输入命令mvn –version检测是否安装成功,出现Maven版本号字样则表示成功。
在Navicat中的test数据库新建test表并设计如下,其中id属性选择为自增:
并添加数据如下:
Eclipse中创建Maven Project,输入相应的包名及项目名,这里的项目名是Select,包名为com,创建好的项目结构如下:
接着使用如下代码替换pom.xml里面的内容:
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>1.0.0</groupId>
<artifactId>dms-get-ecall</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springboot-restful</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<java.version>1.7</java.version>
<mybatis-spring-boot>1.2.0</mybatis-spring-boot>
</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath />
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<!-- Spring Boot Mybatis 依赖 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>${mybatis-spring-boot}</version>
</dependency>
<!-- MySQL 连接驱动依赖 -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<fork>true</fork>
</configuration>
</plugin>
</plugins>
</build>
</project>
在src/main下新建resources文件夹,新建application.properties文件,将如下内容复制:
banner.charset=UTF-8
server.tomcat.uri-encoding=UTF-8
spring.http.encoding.charset=UTF-8
spring.http.encoding.enabled=true
spring.http.encoding.force=true
spring.messages.encoding=UTF-8
server.port=8083
spring.datasource.url=jdbc:mysql://数据库地址:3306/test?useUnicode=true&characterEncoding=utf8&useSSL=false
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
将com.Select下的App.java代码更新如下:
package com.Select;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
* Hello world!
*
*/
@SpringBootApplication
public class App
{
public static void main( String[] args )
{
SpringApplication.run(App.class, args);
System.out.println( "Hello World!" );
}
}
完成之后右键项目,选择Maven/Update Projects更新项目。 接下来在src/main/java下新建entity包,创建Info实体类,该实体类封装的变量对应test数据库表中的属性,代码如下:
package com.Select.entity;
public class Info {
private int id;
private String name;
private String sex;
private String birthday;
private String address;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public String getBirthday() {
return birthday;
}
public void setBirthday(String birthday) {
this.birthday = birthday;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
继续在entity包下创建InfoResult类,作用是将Info类的参数封装成列表形式,代码如下:
package com.Select.entity;
import java.util.ArrayList;
public class InfoResult {
private ArrayList<Info> info;
public ArrayList<Info> getInfo() {
return info;
}
public void setInfo(ArrayList<Info> info) {
this.info = info;
}
}
在src/main/java下新建dao包,新建InfoDao接口,实现对数据库的查询操作:
package com.Select.dao;
import java.util.List;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;
import com.Select.entity.Info;
@Mapper
public interface InfoDao {
@Select("select\t\n"+
"id,\t\n"+
"name,\t\n"+
"sex,\t\n"+
"birthday,\t\n"+
"address\t\n"+
"from\t\n"+
"test\t\n"
)
List<Info> selectInfo();
}
在src/main/java下新建service包,新建InfoService接口,添加要用到的方法:
package com.Select.service;
import com.Select.entity.InfoResult;
public interface InfoService {
InfoResult selectInfoResult();
}
在src/main/java下新建serviceimpl包,新建InfoServiceImpl类,重写InfoService中声明的方法:
package com.Select.serviceimpl;
import java.util.ArrayList;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.Select.dao.InfoDao;
import com.Select.entity.Info;
import com.Select.entity.InfoResult;
import com.Select.service.InfoService;
@Service
public class InfoServiceImpl implements InfoService{
@Autowired
private InfoDao infoDao;
@Override
public InfoResult selectInfoResult() {
InfoResult infoResult = new InfoResult();
infoResult.setInfo((ArrayList<Info>) infoDao.selectInfo());
return infoResult;
}
}
在src/main/java下新建controller包,新建InfoController类来处理请求返回数据:
package com.Select.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import com.Select.entity.InfoResult;
import com.Select.service.InfoService;
@RestController
@RequestMapping(value="/api")
public class InfoController {
@Autowired
private InfoService infoService;
@PostMapping("/select")
InfoResult selInfoResult() {
return infoService.selectInfoResult();
}
}
至此,整个项目已搭建完毕,整体的框架如下: 然后就可以运行程序了:右键App.java,选择运行方式-Java应用程序,如果不出意外控制台会出现Hello World!,然后打开postman设置如下信息: 点击send之后就可以成功获取到test数据库表的所有数据:
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