[Java知识库]10.SpringBoot实战演练

📝 个人主页：程序员阿红🔥
👑 生活平淡，用心就会发光，岁月沉闷，跑起来，就会有风
📣 推荐文章：
📚📚📚 【毕业季·进击的技术er】忆毕业一年有感
📚📚📚 Java 学习路线一条龙版
📚📚📚 一语详解SpringBoot全局配置文件

实战技能补充：lombok

<dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>1.18.12</version>
      <!--只在编译阶段生效-->
      <scope>provided</scope>
    </dependency>

需求：实现用户的CRUD功能

1. 创建springboot工程

2. 导入pom.xml

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.1.3</version>
</dependency>

3. User实体类编写

@Data
public class User implements Serializable {
  private Integer id;
  private String username;
  private String password;
  private String birthday;
  private static final long serialVersionUID = 1L;
}

4.UserMapper编写及Mapper文件

public interface UserMapper {
  int deleteByPrimaryKey(Integer id);
  int insert(User record);
  int insertSelective(User record);
  		User selectByPrimaryKey(Integer id);
  int updateByPrimaryKeySelective(User record);
  int updateByPrimaryKey(User record);
  List<User> queryAll();
}

<?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.example.base.mapper.UserMapper">
 <resultMap id="BaseResultMap" type="com.example.base.pojo.User">
  <id column="id" jdbcType="INTEGER" property="id" />
  <result column="username" jdbcType="VARCHAR" property="username" />
  <result column="password" jdbcType="VARCHAR" property="password" />
  <result column="birthday" jdbcType="VARCHAR" property="birthday" />
 </resultMap>
 <sql id="Base_Column_List">
 id, username, password, birthday
 </sql>
 <select id="selectByPrimaryKey" parameterType="java.lang.Integer"
resultMap="BaseResultMap">
 select
  <include refid="Base_Column_List" />
 from user
 where id = #{id,jdbcType=INTEGER}
 </select>
  <select id="queryAll" resultType="com.example.base.pojo.User">
  select <include refid="Base_Column_List" />
  from user
  </select>
 .......
</mapper>

5. UserService接口及实现类编写

import com.lagou.mapper.UserMapper;
import com.lagou.pojo.User;
import com.lagou.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> queryAll() {
    return userMapper.queryAll();
 }
  @Override
  public User findById(Integer id) {
    return userMapper.selectByPrimaryKey(id);
 }
  @Override
  public void insert(User user) {
    //userMapper.insert(user);    //将除id所有的列都拼SQL
    userMapper.insertSelective(user); //只是将不为空的列才拼SQL
 }
  @Override
  public void deleteById(Integer id) {
    userMapper.deleteByPrimaryKey(id);
 }
  @Override
  public void update(User user) {
    userMapper.updateByPrimaryKeySelective(user);
 }
}

6. UserController编写

import com.lagou.pojo.User;
import com.lagou.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import org.yaml.snakeyaml.events.Event;
import java.util.List;
@RestController
@RequestMapping("/user")
public class UserController {
  @Autowired
  private UserService userService;
  /**
  * restful格式进行访问
  * 查询：GET
  * 新增: POST
  * 更新：PUT
  * 删除: DELETE
  */
  /**
  * 查询所有
  * @return
  */
  @GetMapping("/query")
  public List<User> queryAll(){
    return userService.queryAll();
 }
  /**
  * 通过ID查询
  */
  @GetMapping("/query/{id}")
  public User queryById(@PathVariable Integer id){
    return userService.findById(id);
 }
  /**
  * 删除
  * @param id
  * @return
  */
  @DeleteMapping("/delete/{id}")
  public String delete(@PathVariable Integer id){
    userService.deleteById(id);
    return "删除成功";
 }
  /**
  * 新增
  * @param user
  * @return
  */
  @PostMapping("/insert")
  public String insert(User user){
    userService.insert(user);
    return "新增成功";
 }
  /**
  * 修改
  * @param user
  * @return
  */
  @PutMapping("/update")
  public String update(User user){
    userService.update(user);
    return "修改成功";
 }
}

7. application.yml

##服务器配置
server:
port: 8090
servlet:
 context-path: /
##数据源配置
spring:
datasource:
 name: druid
 type: com.alibaba.druid.pool.DruidDataSource
 url: jdbc:mysql://localhost:3306/springbootdata?characterEncoding=utf-
8&serverTimezone=UTC
 username: root
 password: wu7787879
#整合mybatis
mybatis:
mapper-locations: classpath:mapper/*Mapper.xml
#声明Mybatis映射文件所在的位置

8. 启动类

@SpringBootApplication
//使用的Mybatis,扫描com.lagou.mapper
@MapperScan("com.lagou.mapper")
public class Springbootdemo5Application {
  public static void main(String[] args) {
    SpringApplication.run(Springbootdemo5Application.class, args);
 }
}

9. 使用Postman测试

10.Spring Boot项目部署

需求：将Spring Boot项目使用maven指令打成jar包并运行测试

分析：

1. 需要添加打包组件将项目中的资源、配置、依赖包打到一个jar包中；可以使用maven的
   package ；
2. 部署：java -jar 包名

步骤实现：

• 添加打包组件

<build>
    <plugins>
     <!-- 打jar包时如果不配置该插件，打出来的jar包没有清单文件 -->
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

• 部署运行

java -jar 包名

💖💖💖 完结撒花

💖💖💖 如果命运是世上最烂的编剧。 那么你就要争取，做你人生最好的演员

💖💖💖 写作不易，如果您觉得写的不错，欢迎给博主点赞、收藏、评论来一波~让博主更有动力吧