co.cask.cdap.logging.gateway.handlers.LogReaderCallback.java Source code

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Here is the source code for co.cask.cdap.logging.gateway.handlers.LogReaderCallback.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.logging.gateway.handlers;

import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.PatternLayout;
import co.cask.cdap.logging.read.Callback;
import co.cask.cdap.logging.read.LogEvent;
import co.cask.http.HttpResponder;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;
import org.apache.commons.lang.StringEscapeUtils;
import org.jboss.netty.handler.codec.http.HttpResponseStatus;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Callback to handle log events from LogReader.
 */
class LogReaderCallback implements Callback {
    private final JsonArray logResults;
    private final HttpResponder responder;
    private final PatternLayout patternLayout;
    private final boolean escape;

    LogReaderCallback(HttpResponder responder, String logPattern, boolean escape) {
        this.logResults = new JsonArray();
        this.responder = responder;
        this.escape = escape;

        ch.qos.logback.classic.Logger rootLogger = (ch.qos.logback.classic.Logger) LoggerFactory
                .getLogger(Logger.ROOT_LOGGER_NAME);
        LoggerContext loggerContext = rootLogger.getLoggerContext();

        this.patternLayout = new PatternLayout();
        this.patternLayout.setContext(loggerContext);
        this.patternLayout.setPattern(logPattern);
    }

    @Override
    public void init() {
        patternLayout.start();
    }

    @Override
    public void handle(LogEvent event) {
        String log = patternLayout.doLayout(event.getLoggingEvent());
        log = escape ? StringEscapeUtils.escapeHtml(log) : log;

        JsonObject jsonObject = new JsonObject();
        jsonObject.addProperty("log", log);
        jsonObject.addProperty("offset", event.getOffset());
        logResults.add(jsonObject);
    }

    @Override
    public void close() {
        patternLayout.stop();
        responder.sendJson(HttpResponseStatus.OK, logResults);
    }
}