co.cask.cdap.client.rest.RestStreamWriter.java Source code

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Here is the source code for co.cask.cdap.client.rest.RestStreamWriter.java

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/*
 * Copyright  2014 Cask Data, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package co.cask.cdap.client.rest;

import co.cask.cdap.client.StreamWriter;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.ListeningExecutorService;
import com.google.common.util.concurrent.MoreExecutors;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ByteArrayEntity;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.Map;
import java.util.concurrent.Callable;
import java.util.concurrent.Executors;

/**
 * Stream writer implementation used REST Api for write Streams to processing server.
 */
public class RestStreamWriter implements StreamWriter {
    private static final Logger LOG = LoggerFactory.getLogger(RestStreamWriter.class);

    private final RestClient restClient;
    private final String streamName;
    private final ListeningExecutorService pool;

    public RestStreamWriter(RestClient restClient, int writerPoolSize, String streamName) {
        this.restClient = restClient;
        this.streamName = streamName;
        this.pool = MoreExecutors.listeningDecorator(Executors.newFixedThreadPool(writerPoolSize));
    }

    @Override
    public ListenableFuture<Void> write(String str, Charset charset) {
        return write(str, charset, ImmutableMap.<String, String>of());
    }

    @Override
    public ListenableFuture<Void> write(String str, Charset charset, Map<String, String> headers)
            throws IllegalArgumentException {
        Preconditions.checkArgument(str != null, "Input string parameter is null.");
        return write(new ByteArrayEntity(charset != null ? str.getBytes(charset) : str.getBytes()), headers);
    }

    @Override
    public ListenableFuture<Void> write(ByteBuffer buffer) {
        return write(buffer, ImmutableMap.<String, String>of());
    }

    @Override
    public ListenableFuture<Void> write(ByteBuffer buffer, Map<String, String> headers)
            throws IllegalArgumentException {
        Preconditions.checkArgument(buffer != null, "ByteBuffer parameter is null.");
        HttpEntity content;
        if (buffer.hasArray()) {
            content = new ByteArrayEntity(buffer.array(), buffer.arrayOffset() + buffer.position(),
                    buffer.remaining());
        } else {
            byte[] bytes = new byte[buffer.remaining()];
            buffer.get(bytes);
            content = new ByteArrayEntity(bytes);
        }
        return write(content, headers);
    }

    private ListenableFuture<Void> write(HttpEntity entity, Map<String, String> headers) {
        final HttpPost postRequest = new HttpPost(restClient.getBaseURL()
                .resolve(String.format("/%s/streams/%s", restClient.getVersion(), streamName)));

        for (Map.Entry<String, String> entry : headers.entrySet()) {
            postRequest.setHeader(streamName + "." + entry.getKey(), entry.getValue());
        }

        postRequest.setEntity(entity);

        return pool.submit(new Callable<Void>() {
            @Override
            public Void call() throws Exception {
                CloseableHttpResponse response = restClient.execute(postRequest);
                try {
                    LOG.info("Write stream execute with response: " + response);
                    RestClient.responseCodeAnalysis(response);
                } finally {
                    response.close();
                }
                return null;
            }
        });
    }

    @Override
    public void close() throws IOException {
        pool.shutdown();
        restClient.close();
    }

    public String getStreamName() {
        return streamName;
    }
}