JAVA使用阿里云Serverless 函数计算将OSS文件打包成Zip批量下载

╰半橙微兮° 2022-09-06 10:28 176阅读 0赞

# 批量下载OSS文件的几种方法 #

1.  单个文件依次下载  
    阿里云OSS中批量下载文件使用的就是这种单个文件依次下载的方法，下载时会弹出提示，体验不是很好，也无法下载文件夹保持文件目录结构  
    ![image.png][]
2.  将OSS文件下载到自己服务器中，然后自己生成一个Zip文件，完成批量下载

这种方法的缺点 下载比较慢、如果文件过多会消耗服务器CPU资源和带宽

1.  使用阿里云函数计算打包OSS文件下载

阿里云函数计算官方Demo中有一个python的例子，可惜python用的不多，所以使用Java实现一个类似的功能  
![image.png][image.png 1]

# 使用JAVA 打包OSS文件 #

1.  创建Maven项目，添加阿里云函数计算依赖

<dependencies>
        <dependency>
            <groupId>com.aliyun.fc.runtime</groupId>
            <artifactId>fc-java-core</artifactId>
            <version>1.4.0</version>
        </dependency>
        <dependency>
            <groupId>com.aliyun.fc.runtime</groupId>
            <artifactId>fc-java-common</artifactId>
            <version>2.2.2</version>
        </dependency>
        <dependency>
            <groupId>commons-io</groupId>
            <artifactId>commons-io</artifactId>
            <version>2.11.0</version>
        </dependency>
    </dependencies>
    <build>
        <finalName>zip-oss</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>prepare-package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                        <configuration>
                            <outputDirectory>${
        project.build.directory}/classes/lib</outputDirectory>
                            <includeScope>runtime</includeScope>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

1.  实现Http触发接口

package example;
    
    import com.aliyun.fc.runtime.Context;
    import com.aliyun.fc.runtime.Credentials;
    import com.aliyun.fc.runtime.HttpRequestHandler;
    import com.aliyun.oss.OSSClient;
    import com.aliyun.oss.model.OSSObject;
    import org.apache.commons.io.IOUtils;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.*;
    import java.util.zip.ZipEntry;
    import java.util.zip.ZipOutputStream;
    
    
    public class App implements HttpRequestHandler {
        
    
        String endpoint = "oss-cn-hangzhou.aliyuncs.com";
    
    
        public void handleRequest(HttpServletRequest request, HttpServletResponse response, Context context)
                throws IOException {
        
            String bucket = request.getParameter("bucket");
            String objectKey= request.getParameter("objectKey");
            Credentials creds = context.getExecutionCredentials();
            OSSClient client = new OSSClient(endpoint, creds.getAccessKeyId(), creds.getAccessKeySecret(), creds.getSecurityToken());
            response.setContentType("application/x-zip-compressed");
            ZipOutputStream zipOutputStream = new ZipOutputStream(response.getOutputStream());
            String [] objectKeys=objectKey.split(",");
            for (String key : objectKeys) {
        
                OSSObject ossObject = client.getObject(bucket, key);
                ZipEntry zipEntry = new ZipEntry(key);
                zipOutputStream.putNextEntry(zipEntry);
                IOUtils.copy(ossObject.getObjectContent(), zipOutputStream);
                ossObject.close();
            }
            zipOutputStream.closeEntry();
            zipOutputStream.finish();
        }
    }

3.打包工程

`mvn clean package`

# 将Jar包部署到阿里云函数计算 #

1.新建函数

![image.png][image.png 2]

2.部署jar包

![image.png][image.png 3]

3.创建Http触发器  
![image.png][image.png 4]

4.测试下载  
浏览器访问触发HTTP地址，增加bucket参数和要下载的文件名即可打包下载OSS文件了

`http://XXX.cn-hangzhou.fc.aliyuncs.com/2016-08-15/proxy/app_test.LATEST/java_zhaochao/?bucket=XXX-public&objectKey=1.jpg,1.mp4`

![image.png][image.png 5]

[image.png]: /images/20220829/58b3c8b1219e45dead8d1bbc4c471d7b.png
[image.png 1]: /images/20220829/8fb32a5b6f9149ecb614cceeaf86135b.png
[image.png 2]: /images/20220829/365e83f4ca684ee195e2c07e4bbe07b8.png
[image.png 3]: /images/20220829/f869f5a0a2fd41d8ae24128159ffc789.png
[image.png 4]: /images/20220829/08e9be2f20b8446a9bd5bf8bbf7066d1.png
[image.png 5]: /images/20220829/41b75d2d7ef74410b126638c1090c24b.png