springboot自定义starter源码笔记-蒲公英云

starter：
1、这个场景需要使用到的依赖是什么？
2、如何编写自动配置

@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、模式：
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：
1）、启动器模块

<?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>
    <groupId>com.atguigu.starter</groupId>
    <artifactId>atguigu‐spring‐boot‐starter</artifactId>
    <version>1.0‐SNAPSHOT</version>
    <!‐‐启动器‐‐>
    <dependencies>
    <!‐‐引入自动配置模块‐‐>
        <dependency>
            <groupId>com.atguigu.starter</groupId>
            <artifactId>atguigu‐spring‐boot‐starter‐autoconfigurer</artifactId>
            <version>0.0.1‐SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

2）、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>
    <groupId>com.atguigu.starter</groupId>
    <artifactId>atguigu‐spring‐boot‐starter‐autoconfigurer</artifactId>
    <version>0.0.1‐SNAPSHOT</version>
    <packaging>jar</packaging>
    <name>atguigu‐spring‐boot‐starter‐autoconfigurer</name>
    <description>Demo project for Spring Boot</description>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring‐boot‐starter‐parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath/> <!‐‐ lookup parent from repository ‐‐>
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF‐8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF‐8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <!‐‐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>
    </dependencies>
</project>
package com.atguigu.starter;
import org.springframework.boot.context.properties.ConfigurationProperties;
@ConfigurationProperties(prefix = "atguigu.hello")
public class HelloProperties {
    private String prefix;
    private String suffix;
    public String getPrefix() {
        return prefix;
    }
    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }
    public String getSuffix() {
        return suffix;
    }
    public void setSuffix(String suffix) {
        this.suffix = suffix;
    }
}
package com.atguigu.starter;
public class HelloService {
    HelloProperties helloProperties;
    public HelloProperties getHelloProperties() {
        return helloProperties;
    }
    public void setHelloProperties(HelloProperties helloProperties) {
        this.helloProperties = helloProperties;
    }
    public String sayHellAtguigu(String name){
        return helloProperties.getPrefix()+"‐" +name + helloProperties.getSuffix();
    }
}
package com.atguigu.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 //web应用才生效
@EnableConfigurationProperties(HelloProperties.class)
    public class HelloServiceAutoConfiguration {
    @Autowired
    HelloProperties helloProperties;
    @Bean
    public HelloService helloService(){
    HelloService service = new HelloService();
    service.setHelloProperties(helloProperties);
        return service;
    }
}