Question

我有一个S3存储桶xxx。我编写了一个lambda函数来访问s3存储桶中的数据并将这些细节写入RDS PostgreSQL实例。我可以用我的代码完成它。我在lambda函数中添加了一个触发器，用于在文件落在s3上时调用它。

但是从我的代码中我只能读取名为＆＃39; sampleData.csv＆＃39;的文件。考虑下面给出的代码

public class LambdaFunctionHandler implements RequestHandler<S3Event, String> {

private AmazonS3 s3 = AmazonS3ClientBuilder.standard().build();

public LambdaFunctionHandler() {}

// Test purpose only.
LambdaFunctionHandler(AmazonS3 s3) {
    this.s3 = s3;
}

@Override
public String handleRequest(S3Event event, Context context) {
    context.getLogger().log("Received event: " + event);
    String bucket = "xxx";
    String key = "SampleData.csv";




     System.out.println(key);

     try {
         S3Object response = s3.getObject(new GetObjectRequest(bucket, key));
         String contentType = response.getObjectMetadata().getContentType();
         context.getLogger().log("CONTENT TYPE: " + contentType);
      // Read the source file as text
         AmazonS3 s3Client = new AmazonS3Client();
         String body = s3Client.getObjectAsString(bucket, key);
         System.out.println("Body: " + body);
         System.out.println();
         System.out.println("Reading as stream.....");
         System.out.println();

         BufferedReader br = new BufferedReader(new InputStreamReader(response.getObjectContent()));
  // just saving the excel sheet data to the DataBase       
         String csvOutput;
         try { 
            Class.forName("org.postgresql.Driver");
            Connection con = DriverManager.getConnection("jdbc:postgresql://ENDPOINT:5432/DBNAME","USER", "PASSWORD");
            System.out.println("Connected");
            // Checking EOF
         while ((csvOutput = br.readLine()) != null) {
            String[] str = csvOutput.split(",");
            String name = str[1];
            String query = "insert into schema.tablename(name) values('"+name+"')";
            Statement statement = con.createStatement();
            statement.executeUpdate(query);

         }
         System.out.println("Inserted Successfully!!!");
         }catch (Exception ase) {
            context.getLogger().log(String.format(
                     "Error getting object %s from bucket %s. Make sure they exist and"
                     + " your bucket is in the same region as this function.", key, bucket));
            // throw ase;
         }


         return contentType;
     } catch (Exception e) {
         e.printStackTrace();
         context.getLogger().log(String.format(
             "Error getting object %s from bucket %s. Make sure they exist and"
             + " your bucket is in the same region as this function.", key, bucket));
         throw e;
     }
}

从我的代码中你可以看到我提到了key =＆＃34; SampleData.csv＆＃34 ;;有没有办法在没有指定特定文件名的情况下获取桶内的密钥？

Answer 1

这些链接会有所帮助。

http://docs.aws.amazon.com/AmazonS3/latest/dev/ListingKeysHierarchy.html http://docs.aws.amazon.com/AmazonS3/latest/dev/ListingObjectKeysUsingJava.html

您可以使用前缀和分隔符列出对象，以便在不传递特定文件名的情况下查找您要查找的密钥。

Answer 2

如果您需要获取S3上的事件详细信息，您实际上可以将s3事件通知程序启用为lambda函数。 Refer the link 您可以通过

启用此功能

点击＆＃39;属性＆＃39;在你的桶里面
点击＆＃39;事件＆＃39;
点击＆＃39;添加通知＆＃39;
提供名称并选择事件类型（例如，放置，删除等）
如有必要，请提供前缀和后缀，或留空以考虑所有事件
然后发送给＆＃39; Lambda函数并提供Lambda ARN。

现在事件详细信息将以lambda函数的形式发送为json格式。你可以从那个json中获取细节。输入将是这样的：

{＆＃34;记录＆＃34;：[{＆＃34; eventVersion＆＃34;：＆＃34; 2.0＆＃34;＆＃34; EventSource的＆＃34;：＆＃34; AWS：S3＆＃34;＆＃34; awsRegion＆＃34;：＆＃34; AP-南-1＆＃34;＆＃34; EVENTTIME＆＃34;：＆＃34; 2017-11-23T09：25：54.845Z＆＃ 34;，＆＃34; eventName的＆＃34;：＆＃34; ObjectRemoved：删除＆＃34;＆＃34;的UserIdentity＆＃34; {＆＃34; principalId＆＃34;：＆＃34; AWS：AIDAJASDFGZTLA6UZ7YAK＆＃ 34;}＆＃34; requestParameters的＆＃34; {＆＃34; sourceIPAddress＆＃34;：＆＃34; 52.95.72.70＆＃34;}＆＃34; responseElements＆＃34; {＆＃34;的x AMZ-请求-ID＆＃34;：＆＃34; A235BER45D4974E＆＃34;＆＃34; X-AMZ-ID-2＆＃34;：＆＃34; glUK9ZyNDCjMQrgjFGH0t7Dz19eBrJeIbTCBNI + Pe9tQugeHk88zHOY90DEBcVgruB9BdU0vV8 =＆＃34;}，＆＃34; S3＆＃34; {＆＃34; s3SchemaVersion＆＃34;：＆＃34; 1.0＆＃34;＆＃34; configurationId＆＃34;：＆＃34; SNS＆＃34;＆＃34;桶＆＃34; {＆＃34;名称＆＃34;：＆＃34;例如-bucket1＆＃34;＆＃34; ownerIdentity＆＃34; {＆＃34; principalId＆＃34;：＆＃34; AQFXV36adJU8＆＃34;}＆＃34; ARN＆＃34;：＆＃34; ARN：AWS：S3 :::例如-bucket1＆＃34;}＆＃34;对象＆＃34; {＆＃34;键＆＃ 34;：＆＃34; SampleData.csv＆＃34;＆＃34;定序＆＃34;：＆＃34; 005A169422CA7CDF66＆＃34;}}}]}

您可以访问密钥objectname = event['Records'][0]['s3']['object']['key']（哎呀，这是for python）然后将此信息发送给RDS。

从s3存储桶访问指定的密钥？

2 个答案: