SpringBoot自定义一个starter

@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,

启动器只用来做依赖导入；
专门来写一个自动配置模块；
启动器依赖自动配置；别人只需要引入启动器（starter）
mybatis-spring-boot-starter；自定义启动器名-spring-boot-starter

步骤：

　　启动器模块(就是一个Maven项目)：

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>ustc-anmin-starter</groupId>
    <artifactId>ustc-anmin-spring-boot-starter</artifactId>
    <version>1.0-SNAPSHOT</version>


    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>10</maven.compiler.source>
        <maven.compiler.target>10</maven.compiler.target>
    </properties>

    <!--引入自动配置模块-->
    <dependencies>
        <dependency>
            <groupId>ustc.anmin.starter</groupId>
            <artifactId>anmin-spring-boot-starter-autoconfigure</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>

</project>

　　自动配置模块

<?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 http://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>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>ustc.anmin.starter</groupId>
    <artifactId>anmin-spring-boot-starter-autoconfigure</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>anmin-spring-boot-starter-autoconfigure</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>
    </dependencies>



</project>

package ustc.anmin.starter;

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

@ConfigurationProperties(prefix = "ustc.anmin")
public class HelloServiceProperty {
    private String prefix;
    private String suffix;

    public String getSuffix() {
        return suffix;
    }

    public void setSuffix(String suffix) {
        this.suffix = suffix;
    }

    public String getPrefix() {
        return prefix;
    }

    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }
}

package ustc.anmin.starter;

public class HelloService {
    HelloServiceProperty helloServiceProperty;

    public String sayHelloAnmin(String name){
        return helloServiceProperty.getPrefix() + name + helloServiceProperty.getSuffix();
    }

    public HelloServiceProperty getHelloServiceProperty() {
        return helloServiceProperty;
    }

    public void setHelloServiceProperty(HelloServiceProperty helloServiceProperty) {
        this.helloServiceProperty = helloServiceProperty;
    }
}

package ustc.anmin.starter;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
@ConditionalOnWebApplication
@EnableConfigurationProperties(HelloServiceProperty.class)  //将配置类加入容器
public class HelloServiceAutoConfiguration {
    @Autowired
    HelloServiceProperty helloServiceProperty;

    @Bean
    public HelloService helloService(){
        HelloService service = new HelloService();
        service.setHelloServiceProperty(helloServiceProperty);
        return new HelloService();
    }
}

spring.factories文件

org.springframework.boot.autoconfigure.EnableAutoConfiguration=
  ustc.anmin.starter.HelloServiceAutoConfiguration

test controller

<?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 http://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>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>ustc.anmin</groupId>
    <artifactId>starter-test</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>starter-test</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-web</artifactId>
        </dependency>

        <dependency>
            <groupId>ustc.anmin.starter</groupId>
            <artifactId>ustc-anmin-spring-boot-starter</artifactId>
            <version>1.0-SNAPSHOT</version>
        </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>

</project>

package ustc.anmin.starter.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import ustc.anmin.starter.HelloService;

@RestController
public class HelloController {

    @Autowired
    HelloService service;

    @GetMapping("/hello")
    public String hello(){
        return service.sayHelloAnmin("---anmin---");
    }

}