接口的讲解

在这里之前我想童鞋们都学习过了springmvc。mybatis-plus。Springboot等一些框架

那么下面我们就整合这些框架

我们通过写crud这些接口

写接口的第一步就是引入pom文件

<?xml version="1.0" encoding="UTF-8"?>
<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><!--引入父级工程--><parent><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-parent</artifactId><version>2.4.5</version><relativePath/></parent><artifactId>jiekou</artifactId><version>1.0-SNAPSHOT</version><properties><maven.compiler.source>16</maven.compiler.source><maven.compiler.target>16</maven.compiler.target></properties><dependencies><!--thymeleaf导入模版工具类--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-thymeleaf</artifactId></dependency><!--SpringMVCjar包文件--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--热部署工具--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-devtools</artifactId><scope>runtime</scope><optional>true</optional></dependency><!--lombok插件--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency><!--测试包--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><!--引入jdbc包--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><!--引入数据库驱动 --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope></dependency><!--spring整合mybatis-plus --><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.4.2</version></dependency></dependencies><!--负责项目打包部署--><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId><configuration><excludes><exclude><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></exclude></excludes></configuration></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><configuration><source>16</source><target>16</target></configuration></plugin></plugins></build></project>

pom文件引入依赖之后那么下一步就需要配置数据库的连接以及我们配置的端口

server:port: 8090spring:datasource:url: jdbc:mysql://127.0.0.1:3306/jt?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=trueusername: rootpassword: wyproot123#整合SpringMVCthymeleaf:#设置页面前缀prefix: classpath:/templates/#设置页面后缀suffix: .html#是否使用缓存cache: falsemybatis-plus:type-aliases-package: com.jt.pojo#type-aliases-package: com.jtmapper-locations: classpath:/mappers/*.xml#开启驼峰映射configuration:map-underscore-to-camel-case: true#添加MP日志  打印执行的sql
logging:level:com.jt.mapper: debug

mapper文件

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.jt"></mapper>

首先我们要写一个实体类pojo，注意这里的属性一定要和数据库的表列相对应

package com.jt.pojo;import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import lombok.experimental.Accessors;import java.io.Serializable;@Data
@Accessors(chain = true)
@TableName("user")  //保证数据安全性和有效性必须序列化
public class User implements Serializable {@TableId(type = IdType.AUTO) //主键自增private Integer id;private String name;private Integer num;}

下一步我们就要写dao层结构

我们因为使用的是mybatis-plus所以我们在这里写的代码比较少这也就是框架的好处

package com.jt.mapper;import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.jt.pojo.User;/*** @author :王闫彭* @date : 2023/5/28*/
public interface UseMapper extends BaseMapper<User> {
}

service层结构

首先写service接口

package com.jt.service;import com.jt.pojo.User;import java.util.List;public interface UserService {List<User> findAll();void insertUser(User user);void updateUser(User user);void deleteUserById(Integer id);
}

service的实现类

package com.jt.service;import com.jt.mapper.UserMapper;
import com.jt.pojo.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;import java.util.List;@Service
public class UserServiceImpl implements UserService{@Autowiredprivate UserMapper userMapper;//mp的查询@Overridepublic List<User> findAll() {return userMapper.selectList(null);}//MP的方式实现入库@Overridepublic void insertUser(User user) {userMapper.insert(user);}//mp的更新@Overridepublic void updateUser(User user) {userMapper.updateById(user);}//mp的删除@Overridepublic void deleteUserById(Integer id) {userMapper.deleteById(id);}
}

controller层结构

package com.jt.controller;import com.jt.pojo.User;
import com.jt.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;import java.util.List;@Controller
public class UserController {@Autowiredprivate UserService userService;@GetMapping("/findUser")@ResponseBodypublic List<User> findAjaxUser(){return userService.findAll();}@RequestMapping("/useraa/{id}/{name}/{num}")@ResponseBodypublic String insertUseraa(User user){userService.insertUser(user);return "添加成功";}@RequestMapping("/userbb/{id}/{name}")@ResponseBodypublic String updateUseraa(User user){userService.updateUser(user);return "更新成功";}@RequestMapping("/usercc/{id}")@ResponseBodypublic String deleteUsercc(@PathVariable Integer id){userService.deleteUserById(id);//重新发起请求..return "删除成功";}}

启动类

package com.jt;import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;@SpringBootApplication
@MapperScan("com.jt.mapper")public class SpringBootRun {public static void main(String[] args) {SpringApplication.run(SpringBootRun.class,args);}
}