[Java知识库] 【项目demo01】项目初始化

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[Java知识库]【项目demo01】项目初始化

作者:token annotation punctuation

我准备开一个系列，就是写一些在简要的学习项目中可能会用到的奇奇怪怪的功能，比如线程池或者统一异常处理类
取名为【项目demo】系列
然后将会同步到GitHub中：https://github.com/Livorth/FunctionalLearning

项目初始化

首先简单的构建一个SpringBoot项目

然后构建基础的实验环境，即连接测试数据库

pom.xml要用什么的时候再加什么，但是首先要有数据库，同时要先简单的把MVC几个层写了

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.5</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>cn.livorth</groupId>
    <artifactId>FunctionalLearning</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>FunctionalLearning</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <!--    在使用日志的时候会要用到-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>
        <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>
        <!--    mysql    -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <!--    Mybatis-Plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.3</version>
        </dependency>
        <!--    lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

    <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>
        </plugins>
    </build>

</project>

进行一个数据库的连

# server
server.port= 8888
spring.application.name=FunctionalLearning

# datasource
spring.datasource.url=jdbc:mysql://localhost:3306/test01?useUnicode=true&characterEncoding=UTF-8&serverTimeZone=GMT
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

并添加些许初始数据

entity层、DAO层、service层、controller层

User.java

package cn.livorth.functionallearning.entity;

import lombok.Data;

/**
	 * @program: FunctionalLearning
	 * @description: 用户
	 * @author: livorth
	 * @create: 2021-10-02 13:15
	 **/
@Data
public class User {
    private int userId;
    private String userName;
    private String password;
}

UserMapper.java，一般操作交给了MybatisPlus，当出现特殊需求的时候再去写Mapper.xml

UserServicepackage cn.livorth.functionallearning.dao;

import cn.livorth.functionallearning.entity.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;

/**
 * @program: FunctionalLearning
 * @description: 用户Mapper
 * @author: livorth
 * @create: 2021-10-02 13:21
 **/
@Mapper
public interface UserMapper extends BaseMapper<User> {
}

UserService.java

package cn.livorth.functionallearning.service;

import cn.livorth.functionallearning.entity.User;

import java.util.List;

/**
 * @program: FunctionalLearning
 * @description: 用户服务
 * @author: livorth
 * @create: 2021-10-02 13:21
 **/
public interface UserService {

    /**
     * 返回全部用户的信息
     * @return
     */
    List<User> getAllUser();
}

UserServiceImpl.java

package cn.livorth.functionallearning.service.impl;

import cn.livorth.functionallearning.dao.UserMapper;
import cn.livorth.functionallearning.entity.User;
import cn.livorth.functionallearning.service.UserService;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @program: FunctionalLearning
 * @description: 用户服务实现
 * @author: livorth
 * @create: 2021-10-02 13:25
 **/
@Service
public class UserServiceImpl implements UserService {

    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> getAllUser() {
        LambdaQueryWrapper<User> queryWrapper = new LambdaQueryWrapper<>();
        return userMapper.selectList(queryWrapper);
    }
}

UserController.java

package cn.livorth.functionallearning.controller;

import cn.livorth.functionallearning.entity.User;
import cn.livorth.functionallearning.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

/**
 * @program: FunctionalLearning
 * @description: 用户Controller
 * @author: livorth
 * @create: 2021-10-02 13:27
 **/
@RestController
@RequestMapping("user")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping
    public List<User> categories(){
        return userService.getAllUser();
    }
}