Enterprise Distributed Application Service:Integrate OSS with a Spring Cloud application on EDAS

Why use OSS

OSS is developed by Alibaba Cloud to provide secure, cost-effective, and highly reliable storage services. It allows you to store large amounts of data in the cloud. OSS provides platform-independent RESTful API operations, which means you can store and access all types of data in applications developed with Spring Cloud.

Prerequisites

Before you begin, make sure that you have:

• An Alibaba Cloud account with OSS activated

• An OSS bucket

• An AccessKey pair (AccessKey ID and AccessKey secret) from the Security Management page

• The OSS endpoint for your bucket's region (see Regions and endpoints)

• JDK 8 or later and Maven installed locally

How it works

Spring Cloud AliCloud OSS integrates Spring Cloud applications with Alibaba Cloud OSS. After you add the starter dependency and configure your credentials, you can:

• Inject an OSS client directly into your Spring beans

• Access OSS objects as Spring Resource instances by using @Value("oss://...")

• Deploy the same application to EDAS without modifying code or configuration

Set up the Maven project

1. Create a Maven project named oss-example.

2. Add the following dependencies to pom.xml:

   Spring Boot 1.x has reached end of life. If you must use Spring Boot 1.x, use version 1.5.x with Spring Cloud Edgware and Spring Cloud Alibaba 1.5.1.RELEASE.

      <parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>2.1.4.RELEASE</version>
          <relativePath/>
      </parent>
   
      <dependencies>
          <dependency>
              <groupId>com.alibaba.cloud</groupId>
              <artifactId>spring-cloud-starter-alicloud-oss</artifactId>
              <version>2.1.1.RELEASE</version>
          </dependency>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-web</artifactId>
          </dependency>
      </dependencies>
   
      <dependencyManagement>
          <dependencies>
              <dependency>
                  <groupId>org.springframework.cloud</groupId>
                  <artifactId>spring-cloud-dependencies</artifactId>
                  <version>Finchley.SR1</version>
                  <type>pom</type>
                  <scope>import</scope>
              </dependency>
          </dependencies>
      </dependencyManagement>

3. Create a package named spring.cloud.alicloud.oss under src/main/java.

Create the application entry point

Create the startup class OssApplication in the spring.cloud.alicloud.oss package. On startup, it checks whether the target bucket exists and creates it if needed.

package spring.cloud.alicloud.oss;

import com.aliyun.oss.OSS;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

import java.net.URISyntaxException;

@SpringBootApplication
public class OssApplication {

    // Replace with your actual bucket name
    public static final String BUCKET_NAME = "test-bucket";

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

    @Bean
    public AppRunner appRunner() {
        return new AppRunner();
    }

    class AppRunner implements ApplicationRunner {
        @Autowired
        private OSS ossClient;

        @Override
        public void run(ApplicationArguments args) throws Exception {
            try {
                if (!ossClient.doesBucketExist(BUCKET_NAME)) {
                    ossClient.createBucket(BUCKET_NAME);
                }
            } catch (Exception e) {
                System.err.println("oss handle bucket error: " + e.getMessage());
                System.exit(-1);
            }
        }
    }
}

Add a sample file

Create a file named oss-test.json in src/main/resources:

{
  "name": "oss-test"
}

Create the REST controller

Create OssController in the spring.cloud.alicloud.oss package. This controller exposes three endpoints for uploading, downloading, and reading files through the Spring Resource interface.

package spring.cloud.alicloud.oss;

import com.aliyun.oss.OSS;
import com.aliyun.oss.common.utils.IOUtils;
import com.aliyun.oss.model.OSSObject;
import org.apache.commons.codec.CharEncoding;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.Resource;
import org.springframework.util.StreamUtils;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.nio.charset.Charset;

@RestController
public class OssController {

    @Autowired
    private OSS ossClient;

    // Access an OSS object as a Spring Resource
    @Value("oss://" + OssApplication.BUCKET_NAME + "/oss-test.json")
    private Resource file;

    /**
     * Uploads oss-test.json from the classpath to the OSS bucket.
     */
    @GetMapping("/upload")
    public String upload() {
        try {
            ossClient.putObject(OssApplication.BUCKET_NAME, "oss-test.json", this
                    .getClass().getClassLoader().getResourceAsStream("oss-test.json"));
        } catch (Exception e) {
            e.printStackTrace();
            return "upload fail: " + e.getMessage();
        }
        return "upload success";
    }

    /**
     * Reads the OSS object through the Spring Resource interface.
     */
    @GetMapping("/file-resource")
    public String fileResource() {
        try {
            return "get file resource success. content: " + StreamUtils.copyToString(
                    file.getInputStream(), Charset.forName(CharEncoding.UTF_8));
        } catch (Exception e) {
            e.printStackTrace();
            return "get resource fail: " + e.getMessage();
        }
    }

    /**
     * Downloads the OSS object directly through the OSS client.
     */
    @GetMapping("/download")
    public String download() {
        try {
            OSSObject ossObject = ossClient.getObject(OssApplication.BUCKET_NAME, "oss-test.json");
            return "download success, content: " + IOUtils
                    .readStreamAsString(ossObject.getObjectContent(), CharEncoding.UTF_8);
        } catch (Exception e) {
            e.printStackTrace();
            return "download fail: " + e.getMessage();
        }
    }
}

Endpoint summary:

Configure credentials and endpoint

1. Get your AccessKey ID and AccessKey secret from the Security Management page.

2. Get the endpoint for your bucket's region. See Regions and endpoints.

3. Create application.properties in src/main/resources: Replace the following placeholders with your actual values:

   Placeholder	Description	Example
   <your-access-key>	AccessKey ID	LTAI5tXxx
   <your-secret-key>	AccessKey secret	xXxXxXx
   <your-endpoint>	Regional endpoint prefix	oss-cn-hangzhou

      spring.application.name=oss-example
      server.port=18084
   
      # Replace with your actual credentials and endpoint
      spring.cloud.alicloud.access-key=<your-access-key>
      spring.cloud.alicloud.secret-key=<your-secret-key>
      spring.cloud.alicloud.oss.endpoint=<your-endpoint>.aliyuncs.com
      management.endpoints.web.exposure.include=*

Verify the result

1. Run the main method of OssApplication to start the service.

2. Open http://127.0.0.1:18084/upload in your browser. If upload success appears, the file was uploaded.

3. Verify in the OSS console: navigate to your bucket, click Files in the left-side navigation pane, and confirm that oss-test.json appears in the file list.

4. Open http://127.0.0.1:18084/download to download the file. The expected output is:

      {
        "name": "oss-test"
      }

5. Open http://127.0.0.1:18084/file-resource to read the file through the Spring Resource interface. The expected output is:

      {
        "name": "oss-test"
      }

If any step fails, check the console logs for errors, fix the issue, and restart the application.

Deploy to EDAS

Spring Cloud AliCloud OSS is developed to respond to the needs of migrating applications from their original development environments to EDAS. Deploy your application without modifying code or configuration.

For deployment steps, see:

• Deploy applications in ECS clusters

• Deploy applications in Kubernetes clusters

Configuration reference

What's next

• OSS product overview

• Regions and endpoints