org.apache.flume.event.EventHelper.java Source code

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Here is the source code for org.apache.flume.event.EventHelper.java

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/*
 * 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.event;

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Arrays;
import java.util.Map;

import com.google.common.base.Strings;
import com.google.common.primitives.Longs;
import org.apache.commons.io.HexDump;
import org.apache.flume.Event;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;

public class EventHelper {

    private static final String HEXDUMP_OFFSET = "00000000";
    private static final String EOL = System.getProperty("line.separator", "\n");
    private static final int DEFAULT_MAX_BYTES = 16;

    private static final Logger LOGGER = LoggerFactory.getLogger(EventHelper.class);

    public static String dumpEvent(Event event) {
        return dumpEvent(event, DEFAULT_MAX_BYTES);
    }

    public static String dumpEvent(Event event, int maxBytes) {
        StringBuilder buffer = new StringBuilder();
        Map<String, String> headers = event.getHeaders();

        if (event.getBody() == null) {
            buffer.append("null");
        } else if (event.getBody().length == 0) {
            // do nothing... in this case, HexDump.dump() will throw an exception
        } else {
            byte[] body = event.getBody();

            String bodyType = null;
            String bodyCharset = null;
            if (headers != null) {
                bodyType = headers.get(Event.bodyType);
                bodyCharset = headers.get(Event.bodyCharset);
                for (Map.Entry<String, String> entry : headers.entrySet()) {
                    MDC.put(entry.getKey(), entry.getValue());
                }
            }

            if (bodyCharset == null)
                bodyCharset = "UTF-8";
            if ("long".equals(bodyType)) {
                return "" + Longs.fromByteArray(body);
            }
            if ("string".equals(bodyType)) {
                return fromBytes(body, bodyCharset);
            }

            byte[] data = Arrays.copyOf(body, Math.min(body.length, maxBytes));
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            try {
                HexDump.dump(data, 0, out, 0);
                String hexDump = new String(out.toByteArray());
                // remove offset since it's not relevant for such a small dataset
                if (hexDump.startsWith(HEXDUMP_OFFSET)) {
                    hexDump = hexDump.substring(HEXDUMP_OFFSET.length());
                }
                buffer.append(hexDump);
            } catch (Exception e) {
                if (LOGGER.isInfoEnabled()) {
                    LOGGER.info("Exception while dumping event", e);
                }
                buffer.append("...Exception while dumping: ").append(e.getMessage());
            }
            String result = buffer.toString();
            if (result.endsWith(EOL) && buffer.length() > EOL.length()) {
                buffer.delete(buffer.length() - EOL.length(), buffer.length()).toString();
            }
        }
        return "{ headers:" + headers + " body:" + buffer + " }";
    }

    private static String fromBytes(byte[] body, String bodyCharset) {
        try {
            return new String(body, bodyCharset);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }
}