开发

第一步：创建starter工程hello-spring-boot-starter并配置pom.xml文件

<?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>2.2.2.RELEASE</version><relativePath/></parent><groupId>cn.itcast</groupId><artifactId>hello-spring-boot-starter</artifactId><version>1.0-SNAPSHOT</version><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-autoconfigure</artifactId></dependency></dependencies>
</project>

第二步：创建配置属性类HelloProperties

package cn.itcast.config;import org.springframework.boot.context.properties.ConfigurationProperties;/**读取配置文件转换为bean* */
@ConfigurationProperties(prefix = "hello")
public class HelloProperties {private String name;private String address;public String getName() {return name;}public void setName(String name) {this.name = name;}public String getAddress() {return address;}public void setAddress(String address) {this.address = address;}@Overridepublic String toString() {return "HelloProperties{" +"name='" + name + '\'' +", address='" + address + '\'' +'}';}
}

第三步：创建服务类HelloService

package cn.itcast.service;public class HelloService {private String name;private String address;public HelloService(String name, String address) {this.name = name;this.address = address;}public String sayHello(){return "你好！我的名字叫 " + name + "，我来自 " + address;}
}

第四步：创建自动配置类HelloServiceAutoConfiguration

package cn.itcast.config;import cn.itcast.service.HelloService;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;/*
* 配置类，基于Java代码的bean配置
* */@Configuration
@EnableConfigurationProperties(HelloProperties.class)
public class HelloServiceAutoConfiguration {private HelloProperties helloProperties;//通过构造方法注入配置属性对象HelloPropertiespublic HelloServiceAutoConfiguration(HelloProperties helloProperties) {this.helloProperties = helloProperties;}//实例化HelloService并载入Spring IoC容器@Bean@ConditionalOnMissingBeanpublic HelloService helloService(){return new HelloService(helloProperties.getName(),helloProperties.getAddress());}
}

第五步：在resources目录下创建META-INF/spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
cn.itcast.config.HelloServiceAutoConfiguration

至此starter已经开发完成了，可以将当前starter安装到本地maven仓库供其他应用来使用。

使用