一文详解如何从零构建Spring Boot Starter并实现整合

<!-- pom.xml基础配置 -->
<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.example</groupId>
    <artifactId>demo-spring-boot-starter</artifactId>
    <version>1.0.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.0</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-autoconfigure</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-configuration-processor</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>
</project>

// 配置属性类
@ConfigurationProperties(prefix = "demo.service")
public class DemoProperties {
    private String prefix = "[DEFAULT]";
    private String suffix = "[END]";
    private int cacheSize = 100;
    
    // 完整的getter/setter省略
}

public class DemoService {
    private final DemoProperties properties;

    public DemoService(DemoProperties properties) {
        this.properties = properties;
    }

    public String wrap(String content) {
        return properties.getPrefix() + content + properties.getSuffix();
    }
}

@Configuration
@ConditionalOnClass(DemoService.class)
@EnableConfigurationProperties(DemoProperties.class)
public class DemoAutoConfiguration {

    @Bean
    @ConditionalOnMissingBean
    @ConditionalOnProperty(prefix = "demo.service", name = "enabled", havingValue = "true", matchIfMissing = true)
    public DemoService demoService(DemoProperties properties) {
        return new DemoService(properties);
    }

    @Bean
    public static ConfigurationPropertiesBindingPostProcessor 
      configurationPropertiesBindingPostProcessor() {
        return new ConfigurationPropertiesBindingPostProcessor();
    }
}

com.example.config.DemoAutoConfiguration

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD})
@Conditional(OnProductionEnvironmentCondition.class)
public @interface ConditionalOnProduction {}

public class OnProductionEnvironmentCondition implements Condition {
    @Override
    public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
        return "prod".equals(context.getEnvironment().getProperty("app.env"));
    }
}

mvn clean install

<dependency>
    <groupId>com.example</groupId>
    <artifactId>demo-spring-boot-starter</artifactId>
    <version>1.0.0</version>
</dependency>

demo.service.enabled=true
demo.service.prefix=✨
demo.service.suffix=✨
demo.service.cache-size=200

@SpringBootTest
public class DemoStarterIntegrationTest {

    @Autowired(required = false)
    private DemoService demoService;

    @Test
    void contextLoads() {
        assertNotNull(demoService);
        assertEquals("✨TEST✨", demoService.wrap("TEST"));
    }
}

demo.service.prefix=【TEST】
demo.service.suffix=【END】