Contoh menggunakan Amazon S3 Select pada objek

Kode Java berikut mengembalikan nilai kolom pertama untuk setiap record yang disimpan dalam objek yang berisi data yang disimpan dalam CSV format. Kode ini juga meminta agar pesan Progress dan Stats dapat ditampilkan. Anda harus memberikan nama bucket yang valid dan objek yang berisi data dalam CSV format.

Untuk petunjuk cara membuat dan menguji sampel yang berfungsi, lihat Memulai di Panduan AWS SDK for Java Pengembang.

package com.amazonaws;

import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;
import com.amazonaws.services.s3.model.CSVInput;
import com.amazonaws.services.s3.model.CSVOutput;
import com.amazonaws.services.s3.model.CompressionType;
import com.amazonaws.services.s3.model.ExpressionType;
import com.amazonaws.services.s3.model.InputSerialization;
import com.amazonaws.services.s3.model.OutputSerialization;
import com.amazonaws.services.s3.model.SelectObjectContentEvent;
import com.amazonaws.services.s3.model.SelectObjectContentEventVisitor;
import com.amazonaws.services.s3.model.SelectObjectContentRequest;
import com.amazonaws.services.s3.model.SelectObjectContentResult;

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.concurrent.atomic.AtomicBoolean;

import static com.amazonaws.util.IOUtils.copy;

/**
 * This example shows how to query data from S3Select and consume the response in the form of an
 * InputStream of records and write it to a file.
 */

public class RecordInputStreamExample {

    private static final String BUCKET_NAME = "${my-s3-bucket}";
    private static final String CSV_OBJECT_KEY = "${my-csv-object-key}";
    private static final String S3_SELECT_RESULTS_PATH = "${my-s3-select-results-path}";
    private static final String QUERY = "select s._1 from S3Object s";

    public static void main(String[] args) throws Exception {
        final AmazonS3 s3Client = AmazonS3ClientBuilder.defaultClient();

        SelectObjectContentRequest request = generateBaseCSVRequest(BUCKET_NAME, CSV_OBJECT_KEY, QUERY);
        final AtomicBoolean isResultComplete = new AtomicBoolean(false);

        try (OutputStream fileOutputStream = new FileOutputStream(new File (S3_SELECT_RESULTS_PATH));
             SelectObjectContentResult result = s3Client.selectObjectContent(request)) {
            InputStream resultInputStream = result.getPayload().getRecordsInputStream(
                    new SelectObjectContentEventVisitor() {
                        @Override
                        public void visit(SelectObjectContentEvent.StatsEvent event)
                        {
                            System.out.println(
                                    "Received Stats, Bytes Scanned: " + event.getDetails().getBytesScanned()
                                            +  " Bytes Processed: " + event.getDetails().getBytesProcessed());
                        }

                        /*
                         * An End Event informs that the request has finished successfully.
                         */
                        @Override
                        public void visit(SelectObjectContentEvent.EndEvent event)
                        {
                            isResultComplete.set(true);
                            System.out.println("Received End Event. Result is complete.");
                        }
                    }
            );

            copy(resultInputStream, fileOutputStream);
        }

        /*
         * The End Event indicates all matching records have been transmitted.
         * If the End Event is not received, the results may be incomplete.
         */
        if (!isResultComplete.get()) {
            throw new Exception("S3 Select request was incomplete as End Event was not received.");
        }
    }

    private static SelectObjectContentRequest generateBaseCSVRequest(String bucket, String key, String query) {
        SelectObjectContentRequest request = new SelectObjectContentRequest();
        request.setBucketName(bucket);
        request.setKey(key);
        request.setExpression(query);
        request.setExpressionType(ExpressionType.SQL);

        InputSerialization inputSerialization = new InputSerialization();
        inputSerialization.setCsv(new CSVInput());
        inputSerialization.setCompressionType(CompressionType.NONE);
        request.setInputSerialization(inputSerialization);

        OutputSerialization outputSerialization = new OutputSerialization();
        outputSerialization.setCsv(new CSVOutput());
        request.setOutputSerialization(outputSerialization);

        return request;
    }
}

Untuk JavaScript contoh yang menggunakan SelectObjectContent API operasi AWS SDK for JavaScript with the S3 untuk memilih catatan dari JSON dan CSV file yang disimpan di Amazon S3, lihat posting blog Memperkenalkan dukungan untuk Amazon S3 Select di. AWS SDK for JavaScript

Untuk contoh Python menggunakan SQL kueri untuk mencari data yang dimuat ke Amazon S3 sebagai file value (CSV) dipisahkan koma menggunakan S3 Select, lihat posting blog Mengkueri data tanpa server atau database menggunakan Amazon S3 Select.