java框架搭建

分手后的思念是犯贱 2023-10-06 21:37 49阅读 0赞

1.  创建项目

File->new->project->Spring Initializr(统一了java 8)

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基于pom.xml有刚才导入的依赖，将第一个版本号改为2.1.3.RELEASE然后**刷新**

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.3.RELEASE</version>
            <relativePath/> 
        </parent>

2. 框架搭建过程

>     - 搭建：主要框架组成、通用部分（公共的返回结果封装、公共常量、分页封装）
>     - 框架组成
>         - spring boot [2.1.RELEASE]
>         - spring Mvc （web依赖）
>         - Mybatis
>             - 熟练使用（CRUD、链表查询、常见报错）
>         - Mybatis Plus
>         - Lombok
>         - Swagger
>         - 日志
>             - log4j2
>             - logback(默认)
>         -关注点

3.创建controller包和包下测试用包HelloController

package com.qcby.demo.controller;
    
    
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    //@Controller
    //@ResponseBody
    @RequestMapping("hello")
    public class HelloController {
    
        @RequestMapping
        public String index(String name){
            return "hello world:" +name;
        }
    }

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把DemoApplication中的项目启动，会报错，将test文件夹下的DemoApplicationTests当中的junit一行删除，程序会自动导入junit，就可以启动成功。（注意最后两行）

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4.打开网页，输入localhost:8080/hello?name=ws

启动成功的话，就证明 - spring boot - spring Mvc 测试成功

### 二、mybatis整合 ###

1.加入mybatis依赖，点击刷新

<dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>2.1.1</version>
          </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
          </dependency>

2.在resources下面删掉原先的.yml文件，并新建一个application.yml文件

按如下进行配置文件修改

spring:
      datasource:
        url: jdbc:mysql://81.70.242.198:3306/qcby_jiucai?useUnicode=true&characterEncoding=utf-8&serverTimezone=CTT
        username: root
        password: 写入自己的数据库密码
        driver-class-name: com.mysql.cj.jdbc.Driver
    mybatis:
      mapper-locations: classpath:mapper/*.xml  #对应mapper映射xml文件所在路径
      type-aliases-package: com.qcby.demo.entity  #对应实体类路径
      configuration:
        map-underscore-to-camel-case: true

> mapper-locations: classpath:mapper/\*.xml
> 
> 这句话对应着要在resources文件夹下新建一个mapper文件夹，上面是自动扫描到mapper文件夹下.xml文件

> type-aliases-package: com.qcby.demo.entity \#对应实体类路径
> 
> 这句话是在demo下新建一个实体类文件夹entity，并把路径复制过来

3.创建mapper接口，在demo下面建立mapper文件夹，创建个接口UserMapper

package com.qcby.demo.mapper;
    
    import com.qcby.demo.entity.User;
    
    import java.util.List;
    
    public interface UserMapper {
    
    
            List<User> listAll();
    
    }

4.启动类修改，加上

// 启动类修改
      @MapperScan("com.qcby.demo.mapper")//路径为mapper路径
      @SpringBootApplication

package com.qcby.demo;
    
    import org.mybatis.spring.annotation.MapperScan;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    // 启动类修改
    @MapperScan("com.qcby.demo.mapper")
    @SpringBootApplication
    public class DemoApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(DemoApplication.class, args);
        }
    }

5.在resources的mapper下面创建UserMapper.xml文件

<?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.qcby.demo.mapper.UserMapper">  
       
        <resultMap id="BaseResultMap" type="com.qcby.demo.entity.User">  
    
    
        </resultMap>
    
        <sql id="Base_Column_List">
                  id,username,password,head_img,remark,balance
      </sql>
    
    
        <select id="listAll" resultType="com.qcby.demo.entity.User">
           select
            <include refid="Base_Column_List"></include>
            from user
        </select>
        <select id="listAll1" resultType="com.qcby.demo.entity.User">
           select
            <include refid="Base_Column_List"></include>
            from user
        </select>
        <select id="listAll2" resultType="com.qcby.demo.entity.User">
           select
            <include refid="Base_Column_List"></include>
            from user
        </select>
    </mapper>

6.在entity中建立User（这里的字段是数据库user中的字段）

package com.qcby.demo.entity;
    import lombok.Data;
    @Data
    public class User {
    
        private Long id;
        private String username;
        private String password;
        private String headImg;
        private String remark;
        private double balance;
    }

7.在demo下面建立service，并建立UserService接口文件

package com.qcby.demo.service;
    
    import com.qcby.demo.entity.User;
    
    import java.util.List;
    
    public interface UserService {
    
        List<User> listAll();
    }

8.在service下面建立impl文件夹并建立UserServiceImpl文件

package com.qcby.demo.service.impl;
    
    
    import com.qcby.demo.entity.User;
    import com.qcby.demo.mapper.UserMapper;
    import com.qcby.demo.service.UserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import java.util.List;
    
    @Service
    public class UserServiceImpl implements UserService {
        @Autowired
        private UserMapper userMapper;
    
        @Override
        public List<User> listAll() {
            return userMapper.listAll();
        }
    }

9.demo的controller下新建UserController

package com.qcby.demo.controller;
    
    
    import com.qcby.demo.entity.User;
    import com.qcby.demo.service.UserService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.List;
    
    @RestController
    @RequestMapping("user")
    public class UserController {
        @Autowired
        private UserService userService;
    
        @RequestMapping("listAll")
        public List<User> listAll(){
            return userService.listAll();
        }
    }

10.数据库

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11.文件路径

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10.启动----[http://localhost:8080/user/listAll][http_localhost_8080_user_listAll]

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[http_localhost_8080_user_listAll]: http://localhost:8080/user/listAll
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