springboot

SpringBoot

第一个SpringBoot程序

image-20250326104642411

image-20250326104655547

  • 编写controller控制类

    package com.zhm.controller;

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.RestController;

@RestController
@RequestMapping("/books")
public class BookController {

    @GetMapping("/{id}")
    public String getById(@PathVariable Integer id){
        return "hello springboot "+id;
    }
}

  • 启动主程序

    package com.zhm;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootStudyApplication {

   public static void main(String[] args) {
      SpringApplication.run(SpringbootStudyApplication.class, args);
   }

}

springboot简介

  • 优点：简化spring，springmvc，springservlet配置文件，tomcat服务器配置，插件

  • 主要就是靠pom.xml里的parent和dependencies的starter起步依赖，parent继承版本对应的包管理dependencyManagement

    dependencyManagement代表版本声明，子项目调用就不需要写版本号但要dependencies引入

    starter起步依赖

    parent为版本管理，parent主要配置了该springboot版本内各种最佳适配依赖版本号，起作用的还是子项目dependencies引入，两个依赖包含了tomcat服务器等起步依赖

       <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.5.0</version>
      <relativePath/> <!-- lookup parent from repository -->
   </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>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
         </plugin>
      </plugins>
   </build>

  • SpringbootStudyApplication 主启动类，启动后由于starter起步依赖内含tomcat，所以运行tomcat

  • 用哪个版本依赖就看需要的依赖版本号对应的boot是哪个版本

排除依赖

  • 换服务器
<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
   <exclusions>
      <exclusion>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-tomcat</artifactId>
      </exclusion>
   </exclusions>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jetty</artifactId>
</dependency>

三种配置文件

  • image-20250326123414044

  • 主要用application.yml

  • 优先级 properties>yml>yaml

  • yml格式(yaml)

    server:
  port: 81

logging:
  level:
    root: info

yaml数据格式

  1. 记得数据前空格，大小写敏感

  2. 层级用换行+前面空格表示，前面空格一样代表一个层级，空格少层级高

  3. 存多个数据用-加空格加数据

    hobby:
  - music
  - game
  - run

读取yaml数据

server:
  port: 81

logging:
  level:
    root: info

enterprise:
  name: it
  age: 100
  tel: 15347223316
  subject:
    - java
    - 前端
    - 大数据

  1. 直接@Value注解

  2. environment对象自动注入，保存全部数据在内，通过getpropert方法huoq

  3. 定义一个类，@component注解和@ConfigurationProperties（prefix=“类对应的属性值”），对象.get获取

    package com.zhm.domain;

import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;

import java.util.Arrays;

@Component
@ConfigurationProperties(prefix = "enterprise")
public class Enterprise {
    private String name;
    private Integer age;
    private String tel;
    private String[] subject;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public String getTel() {
        return tel;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }

    public String[] getSubject() {
        return subject;
    }

    public void setSubject(String[] subject) {
        this.subject = subject;
    }

    @Override
    public String toString() {
        return "Enterprise{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", tel='" + tel + '\'' +
                ", subject=" + Arrays.toString(subject) +
                '}';
    }
}

    package com.zhm.controller;

import com.zhm.domain.Enterprise;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.env.Environment;
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.RestController;

import javax.swing.*;
import java.util.Arrays;

@RestController
@RequestMapping("/books")
public class BookController {
//    @GetMapping("/{id}")
//    public String getById(@PathVariable Integer id){
//        return "hello springboot "+ id;
//    }

    // 1
    @Value("${server.port}")
    private Integer port;

    @Value("${enterprise.subject[1]}")
    private String name;

    // 2
    @Autowired
    private Environment environment;

    // 3
    @Autowired
    private Enterprise enterprise;

    @GetMapping
    public String getById(){
        System.out.println(port);
        System.out.println(name);
        System.out.println("------------------------------");
        //只能获取单个
//        System.out.println(environment.getProperty("enterprise"));
        System.out.println(environment.getProperty("enterprise.name"));
        System.out.println(environment.getProperty("enterprise.subject[2]"));
        System.out.println("------------------------------");
        System.out.println(enterprise.getName());
        System.out.println(Arrays.toString(enterprise.getSubject()));
        System.out.println(enterprise);
        return "hello springboot ";
    }
}

配置多套生产环境

  • ---隔开，active代表激活用哪一个profiles
  • 这是yaml和yml格式，properties要写多个环境文件，在主application里面用哪一个激活哪一个
spring:
  profiles:
    active: pro

---
# 测试环境
spring:
  profiles: test
server:
  port: 81

---
#开发环境
spring:
  profiles: dev
server:
  port: 82

---
#生产环境
spring:
  profiles: pro
server:
  port: 83

命令行切换运行环境

  • jar包注意点，先clean再打包，文件编码utf-8

    1. 执行jar，jar文件目录cmd

      java -jar springboot-02-application-0.0.1-SNAPSHOT.jar

    2. 修改激活环境

      java -jar springboot-02-application-0.0.1-SNAPSHOT.jar --spring.profiles.active=test

    3. 修改端口号，优先级高

      java -jar springboot-02-application-0.0.1-SNAPSHOT.jar --server.port=88

4种配置文件等级

image-20250326174940812

  • 4级就是resources下的文件，3级的resources下config文件夹下的文件，开发用34
  • 2级是打包jar包同级文件，1是同级config文件夹下文件，发表改用12

整合Junit

  • SpringBootTest注解，加载springboot启动类，classes写启动类位置

  • 写一个service接口和实现类，加上@Service注解，通过启动类加载成功生效

  • package com.zhm;

import com.zhm.service.BookService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

// 这里springboot帮你加载了测试类
// @SpringBootTest这个配置相当于加载springboot启动类（配置文件），如果test目录对应，不用写classes=，否则要加classes = Springboot03JunitApplication.class
// springboot启动类 Springboot03JunitApplication会扫包同级和下级包，service注解才生效
@SpringBootTest(classes = Springboot03JunitApplication.class)
class Springboot03JunitApplicationTests {

    @Autowired
    private BookService bookService;

    @Test
    void getBookTest() {
        bookService.getBook();
    }

}

整合Mybatis

  • 初始化项目，勾选mysql驱动和mybatis框架

    image-20250326211331423

  • 写配置文件，连接数据库信息 application.yml

    spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/ssmbuild
    username: root
    password: 123456

  • 写数据库对应实体类和dao接口

    dao接口要加@mapper实现原来的MapperScannerConfigurer扫dao包，自动装配

    package com.zhm.dao;

import com.zhm.domain.Book;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;

@Mapper
public interface BookDao {

    @Select("select * from book where bookId = #{id}")
    Book getById(@Param("id") Integer id);
}

  • 测试

    package com.zhm;

import com.zhm.dao.BookDao;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class Springboot04MybatisApplicationTests {

    @Autowired
    private BookDao bookDao;

    @Test
    void getById() {
        System.out.println(bookDao.getById(17));
    }

}
posted @ 2025-04-22 22:09  学习java的白菜  阅读(16)  评论(0)    收藏  举报