org.apache.flume.sink.solr.morphline.BlobHandler.java Source code

Introduction

Here is the source code for org.apache.flume.sink.solr.morphline.BlobHandler.java

Source

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.flume.sink.solr.morphline;

import java.io.InputStream;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.conf.ConfigurationException;
import org.apache.flume.event.EventBuilder;
import org.apache.flume.source.http.HTTPSourceHandler;
import org.apache.tika.metadata.Metadata;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * BlobHandler for HTTPSource that returns event that contains the request
 * parameters as well as the Binary Large Object (BLOB) uploaded with this
 * request.
 * <p>
 * Note that this approach is not suitable for very large objects because it
 * buffers up the entire BLOB.
 * <p>
 * Example client usage:
 * <pre>
 * curl --data-binary @sample-statuses-20120906-141433-medium.avro 'http://127.0.0.1:5140?resourceName=sample-statuses-20120906-141433-medium.avro' --header 'Content-Type:application/octet-stream' --verbose
 * </pre>
 */
public class BlobHandler implements HTTPSourceHandler {

    private int maxBlobLength = MAX_BLOB_LENGTH_DEFAULT;

    public static final String MAX_BLOB_LENGTH_KEY = "maxBlobLength";
    public static final int MAX_BLOB_LENGTH_DEFAULT = 100 * 1000 * 1000;

    private static final int DEFAULT_BUFFER_SIZE = 1024 * 8;
    private static final Logger LOGGER = LoggerFactory.getLogger(BlobHandler.class);

    public BlobHandler() {
    }

    @Override
    public void configure(Context context) {
        this.maxBlobLength = context.getInteger(MAX_BLOB_LENGTH_KEY, MAX_BLOB_LENGTH_DEFAULT);
        if (this.maxBlobLength <= 0) {
            throw new ConfigurationException("Configuration parameter " + MAX_BLOB_LENGTH_KEY
                    + " must be greater than zero: " + maxBlobLength);
        }
    }

    @SuppressWarnings("resource")
    @Override
    public List<Event> getEvents(HttpServletRequest request) throws Exception {
        Map<String, String> headers = getHeaders(request);
        InputStream in = request.getInputStream();
        try {
            ByteArrayOutputStream blob = null;
            byte[] buf = new byte[Math.min(maxBlobLength, DEFAULT_BUFFER_SIZE)];
            int blobLength = 0;
            int n = 0;
            while ((n = in.read(buf, 0, Math.min(buf.length, maxBlobLength - blobLength))) != -1) {
                if (blob == null) {
                    blob = new ByteArrayOutputStream(n);
                }
                blob.write(buf, 0, n);
                blobLength += n;
                if (blobLength >= maxBlobLength) {
                    LOGGER.warn("Request length exceeds maxBlobLength ({}), truncating BLOB event!", maxBlobLength);
                    break;
                }
            }

            byte[] array = blob != null ? blob.toByteArray() : new byte[0];
            Event event = EventBuilder.withBody(array, headers);
            LOGGER.debug("blobEvent: {}", event);
            return Collections.singletonList(event);
        } finally {
            in.close();
        }
    }

    private Map<String, String> getHeaders(HttpServletRequest request) {
        if (LOGGER.isDebugEnabled()) {
            Map requestHeaders = new HashMap();
            Enumeration iter = request.getHeaderNames();
            while (iter.hasMoreElements()) {
                String name = (String) iter.nextElement();
                requestHeaders.put(name, request.getHeader(name));
            }
            LOGGER.debug("requestHeaders: {}", requestHeaders);
        }
        Map<String, String> headers = new HashMap();
        if (request.getContentType() != null) {
            headers.put(Metadata.CONTENT_TYPE, request.getContentType());
        }
        Enumeration iter = request.getParameterNames();
        while (iter.hasMoreElements()) {
            String name = (String) iter.nextElement();
            headers.put(name, request.getParameter(name));
        }
        return headers;
    }

}