从S3存储桶中访问指定的密钥

Question

我有一个s3桶xxx。我编写了一个lambda功能，以访问S3存储桶的数据，并将这些详细信息写入RDS PostgreSQL实例。我可以用我的代码做。当文件落在S3上时，我在lambda函数中添加了一个触发器。

但是，从我的代码中，我只能读取名称为" sampledata.csv"的文件。考虑下面给出的我的代码

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，您可以看到我提到了key =" sampledata.csv";有什么方法可以在不指定特定文件名的情况下将键输入存储桶内？

Answer 1

这两个链接将有所帮助。

http://docs.aws.amazon.com/amazons3/latest/dev/listingkeyshierarchy.htmlhttp://docs.aws.amazon.com/amazons3/latest/dev/listingobjectKeysusingjava.html

您可以使用前缀和定界符列出对象，以找到您要寻找的密钥而无需传递特定的文件名。

Answer 2

如果您需要在S3上获取事件详细信息，则实际上可以启用S3事件通知器到lambda函数。参考链接您可以通过

启用此功能

1. 单击您的存储桶内的"属性"
2. 单击"事件"
3. 单击"添加通知"
4. 命名并选择事件类型（例如，dut，delete等）
5. 如有必要，请给前缀和后缀，或者留空，考虑所有事件
6. 然后'发送到'lambda函数并提供lambda arn。

现在，事件详细信息将作为JSON格式发送lambda函数。您可以从该JSON中获取细节。输入将是这样：

{"记录"：[{" eventversion"：" 2.0"，" eventsource"：" aws：s3"，" awsregion"：" ap-south-1"，" eventtime"：" 2017-11-23T09：25：54.845z"，" eventname"：" objectRemaved：delete"，" userIdentity"：{" principalid"：" aws：aidajasdfgztla6uz7yak"}，" requestParameters"}，" requestParameters"：响应仪"：{" X-Amz-Request-id"：" A235BER45D4974E"，" X-AMZ-ID-2"：" GLUK9ZYNDCJMQRGJMQRGJMQRGJMQRGGH0T7DZEBNI PE9TQUGEHKKKKKKHK888ZHOY90DEBCVGR： s3schemaversion"：" 1.0"，"，"configurationId'：" sns"，" bucket"：{" name"：" xplace-bucket1"，" aslorsidentity"：{" principalId"：" aqfxv36adju8"}，" arn"：" arn：aws：aws：aws：s3 :::::: example example-bucket1"}，" object"：{" key"：" sampledata.csv"，" sequencer"：" 005A169422CA7CDF66"}}}}}}}

您可以以objectname = event['Records'][0]['s3']['object']['key']（糟糕，适用于Python）访问键然后将此信息发送给RDS。