SpringBoot自定义Starters

2023-11-26 12:51:34

#如何自定义Starters#

### 1.创建思路 ###
1.这个场景需要用到的依赖是什么?

2.如何编写自动配置,一些注解的功能?

    @Configuration //指定这个类是一个配置类
    @ConditionalOnXXX //在指定条件成立的情况下自动配置类生效
    @AutoConfigureAfter //指定自动配置类的顺序
    @Bean //给容器中添加组件
    @ConfigurationPropertie结合相关xxxProperties类来绑定相关的配置
    @EnableConfigurationProperties //让xxxProperties生效加入到容器中
    自动配置类要能加载
    将需要启动就加载的自动配置类，配置在META‐INF/spring.factories
    org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
    org.springframework.boot.autoconfigure.admin.SpringApplicationAdminJmxAutoConfiguration,\
    org.springframework.boot.autoconfigure.aop.AopAutoConfiguration,\

3.starter的模式:

* 启动器只是用来做依赖导入
* 自动配置模块用来写代码逻辑
* 启动器依赖自动配置,只需要引入启动器会自动引入自动配置
* 自定义启动器名:启动器名-spring-boot-starter

### 2.创建流程 ###
1.创建一个自动配置项目:zhangbao-spring-boot-starter-autoconfigure,在pom.xml文件中导入以下依赖

    <!‐‐引入spring‐boot‐starter；所有starter的基本配置‐‐>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-configuration-processor</artifactId>
        <optional>true</optional>
    </dependency>

2.创建一个maven项目:zhangbao-spring-boot-starter,只在pom.xml文件中导入自动配置项目的依赖

    
    <dependency>
      <groupId>com.zhangbao</groupId>
      <artifactId>zhangbao-spring-boot-starter-autoconfigure</artifactId>
      <version>0.0.1-SNAPSHOT</version>
    </dependency>

3.编写配置类:HelloProperties

    //data注解是lombok插件的注解用来生成属性的get/set方法
    @Data
    @ConfigurationProperties(prefix = "spring.zhangbao.hello")
    public class HelloProperties {

        private String prefix;

        private String suffix;
    }

4.编写业务逻辑类

    @Data
    public class HelloService {

        private HelloProperties helloProperties;

        public String sayHello(String name) {
            return helloProperties.getPrefix() + "-" + name + "-" + helloProperties.getSuffix();
        }
    }

5.编写自动配置类

    @Configuration
    //web环境该配置类才生效
    @ConditionalOnWebApplication
    @EnableConfigurationProperties(HelloProperties.class)
    public class HelloAutoConfigure {

        @Autowired
        private HelloProperties helloProperties;

        @Bean
        public HelloService helloService() {
            HelloService helloService = new HelloService();
            helloService.setHelloProperties(helloProperties);
            return helloService;
        }
    }

6.将自动配置类配置在META‐INF/spring.factories文件中

    org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
    com.zhangbao.config.HelloAutoConfigure

7.使用maven install命令先将zhangbao-spring-boot-starter-autoconfigure项目打包到仓库中

8.然后再使用maven install命令将zhangbao-spring-boot-starter项目打包到仓库中(由于该项目依赖zhangbao-spring-boot-starter-autoconfigure项目所以先将zhangbao-spring-boot-starter-autoconfigure项目打包到仓库中)

9.创建spring-boot-custom-test项目用来测试starter是否创建成功,由于步骤5中自动配置类是在web环境中才生效,所以创建的项目需要导入web依赖

10.测试项目导入zhangbao-spring-boot-starter依赖

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

    
    <dependency>
        <groupId>com.zhangbao</groupId>
        <artifactId>zhangbao-spring-boot-starter</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>

11.创建测试Controller
    @RestController
    public class HelloController {

        //此时注入的就是zhangbao-spring-boot-starter-autoconfigure项目中的HelloService
        @Autowired
        private HelloService helloService;

        @GetMapping("/hello")
        public String hello(String name) {

            return helloService.sayHello(name);
        }
    }

12.在application.yml配置文件中添加步骤3中HelloProperties配置类的prefix和suffix

    spring:
      zhangbao:
        hello:
          prefix: hello
          suffix: welcome

13.启动spring-boot-custom-test项目,在浏览器中输入localhost:8080/hello?name=zhangbao
正常应该显示:hello-zhangbao-welcome

14.自定义Spring Boot Starter成功

15.详细代码见spring-boot-custom文件夹

码农公寓

相关文章