spring boot微服务自定义starter原理详解

<dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-autoconfigure</artifactId>
      <version>2.0.0.RELEASE</version>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

@ConfigurationProperties(prefix = "com.xxx")
public class HelloServiceProperties {

  private String name = "james";

  private String hobby = "cc";

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  public String getHobby() {
    return hobby;
  }

  public void setHobby(String hobby) {
    this.hobby = hobby;
  }
}

public class HelloService {

  private String name;

  private String hobby;

  public String getName() {
    return "name is " + name;
  }

  public String getHobby() {
    return "hobby is " + hobby;
  }

  public void setName(String name) {
    this.name = name;
  }

  public void setHobby(String hobby) {
    this.hobby = hobby;
  }
}

@Configuration
@EnableConfigurationProperties(HelloServiceProperties.class)
@ConditionalOnClass(HelloServiceConfiguration.class)
@ConditionalOnProperty(prefix = "com.xxx", value = "enabled", matchIfMissing = true)@ComponentScan({"com.xxx"}) // 如果bean比较多，一般采用这种方式
public class HelloServiceAutoConfiguration {

  @Autowired
  private HelloServiceProperties helloServiceProperties;

  @Bean // bean比较少、且顺序和逻辑有特殊要求的模块，一般采用这种方式
  @ConditionalOnMissingBean(HelloServiceConfiguration.class)
  public HelloServiceConfiguration helloServiceConfiguration() {
    HelloService helloService = new HelloService();
    helloService.setName(helloServiceProperties.getName());
    helloService.setHobby(helloServiceProperties.getHobby());
    return helloService;
  }
}

org.springframework.boot.autoconfigure.EnableAutoConfiguration=com.xxx.HelloServiceAutoConfiguration

@SpringBootApplication
@RestController
public class Springboot03Application {

  @Autowired
  private HelloService helloService;

  public static void main(String[] args) {
    SpringApplication.run(Springboot03Application.class, args);
  }

  @RequestMapping("/name")
  public String getName() {
    return helloService.getName();
  }

  @RequestMapping("/hobby")
  public String getHobby() {
    return helloService.getHobby();
  }
}