Spring Boot 在无服务器应用程序开发中的应用实战

// pom.xml
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-function-adapter</artifactId>
    <version>2.0.1.RELEASE</version>
</dependency>

// App.java
@SpringBootApplication
public class App {
    public static void main(String[] args) {
        SpringApplication.run(App.class, args);
    }
}

// 发送 HTTP POST 请求触发
@PostMapping("/")
public String httpSample() {
    return "Hello, HTTP!";
}

// 接收队列消息触发
@CloudEvent
public void messageSample(Consumer<String> event) {
    log.info("Event message: " + event.toString());
}

// 对象存储桶更新事件触发
@CloudEvent
public void storageSample(Consumer<StorageObject> event) {
    log.info("Event storage object: " + event.toString());
}

// ImageScaleFunction.java
@CloudEvent
public void imageScale(Consumer<String> event) {
    String filename = event.getData();
    
    // 读取原始图像并缩放
    BufferedImage originalImage = ImageIO.read(new File(filename));
    BufferedImage scaledImage = ... // 缩放逻辑

    // 保存缩放后的图像
    ImageIO.write(scaledImage, "png", new File(filename + "-scaled"));
}