1.创建一个 空项目 xxx-spring-boot-starter 作为场景启动器，方便别人引用
2.创建xxx-spring-boot-autoconfigure：包含自动配置类、属性类、核心服务等
3.注册自动配置（Spring Boot 2.7+ / 3.x）
在resources目录下创建：META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports
文件内容为自动配置类的全限定名，一行一个，例如：
com.example.starter.autoconfigure.GreeterAutoConfiguration
自动配置类
自动配置类是 Starter 的灵魂。它使用条件注解，确保仅在特定条件下生效。
import org.springframework.boot.autoconfigure.AutoConfiguration;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.annotation.Bean;
@AutoConfiguration // Spring Boot 2.7+ 引入，等价于 @Configuration 且有自动配置语义
@EnableConfigurationProperties(GreeterProperties.class)
@ConditionalOnClass(GreeterService.class) // 当类路径中存在该类时才生效
@ConditionalOnProperty(prefix = "greeter", name = "enabled", havingValue = "true", matchIfMissing = true)
public class GreeterAutoConfiguration {
@Bean
@ConditionalOnMissingBean
public GreeterService greeterService(GreeterProperties properties) {
return new GreeterService(properties);
}
}
核心服务类
核心的业务逻辑放在这里
public class GreeterService {
private final GreeterProperties properties;
public GreeterService(GreeterProperties properties) {
this.properties = properties;
}
public String greet(String name) {
return properties.getPrefix() + " " + name + properties.getSuffix();
}
}
属性配置类
配置核心服务类需要的属性名称
import org.springframework.boot.context.properties.ConfigurationProperties;
@ConfigurationProperties(prefix = "greeter")
public class GreeterProperties {
/**
* 问候语前缀，默认为 "Hello"
*/
private String prefix = "Hello";
/**
* 问候语后缀，默认为 "!"
*/
private String suffix = "!";
// getter / setter 略
}
