com.comcast.viper.flume2storm.event.F2SEvent.java Source code

Introduction

Here is the source code for com.comcast.viper.flume2storm.event.F2SEvent.java

Source

/**
 * Copyright 2014 Comcast Cable Communications Management, LLC
 *
 * 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 com.comcast.viper.flume2storm.event;

import java.io.Serializable;
import java.util.Map;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.builder.ToStringBuilder;
import org.apache.commons.lang3.builder.ToStringStyle;

import com.google.common.collect.ImmutableMap;

/**
 * Event object exchanged between Flume and Storm. We keep it close to Flume's
 * original event.<br/>
 * Programming note: We create this duplicate of Flume event in order to avoid
 * having to bring all Flume dependencies into Storm.
 */
public final class F2SEvent implements Serializable {
    private static final long serialVersionUID = -5906404402187281472L;
    private final Map<String, String> headers;
    private final byte[] body;

    F2SEvent() {
        headers = ImmutableMap.of();
        body = new byte[0];
    }

    /**
     * Constructor to build Flume2Storm events
     * 
     * @param headers
     *          See {@link #getHeaders()}. If null, the headers is an empty
     *          immutable map.
     * @param body
     *          See {@link #getBody()}. If null, the payload of the event is an
     *          empty byte array.
     */
    public F2SEvent(Map<String, String> headers, byte[] body) {
        if (headers == null) {
            this.headers = ImmutableMap.of();
        } else {
            this.headers = ImmutableMap.copyOf(headers);
        }
        if (body == null) {
            this.body = ArrayUtils.EMPTY_BYTE_ARRAY;
        } else {
            this.body = ArrayUtils.clone(body);
        }
    }

    /**
     * Copy constructor
     * 
     * @param event
     *          Another Flume2Storm event
     */
    public F2SEvent(F2SEvent event) {
        headers = ImmutableMap.copyOf(event.getHeaders());
        body = event.body;
    }

    /**
     * @return The event body
     */
    public byte[] getBody() {
        return body;
    }

    /**
     * @return The headers (key/value pairs) associated to the event
     */
    public Map<String, String> getHeaders() {
        return headers;
    }

    /**
     * @param key
     *          A header name (i.e. key)
     * @return The value of the header, or null if it does not exist
     */
    public String getHeader(String key) {
        return headers.get(key);
    }

    /**
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        return new HashCodeBuilder().append(headers).append(body).hashCode();
    }

    /**
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        F2SEvent other = (F2SEvent) obj;
        return new EqualsBuilder().append(this.headers, other.headers).append(this.body, other.body).isEquals();
    }

    /**
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        ToStringBuilder toStringBuilder = new ToStringBuilder(this, ToStringStyle.SHORT_PREFIX_STYLE)
                .append("headers", headers);
        String bodyStr = StringUtils.toEncodedString(body, F2SEventFactory.DEFAULT_CHARACTER_SET);
        if (StringUtils.isAsciiPrintable(bodyStr)) {
            toStringBuilder.append("body", bodyStr);
        } else {
            toStringBuilder.append(Hex.encodeHexString(body));
        }
        return toStringBuilder.toString();
    }
}