edu.kit.dama.ui.simon.impl.WebServerProbe.java Source code

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Here is the source code for edu.kit.dama.ui.simon.impl.WebServerProbe.java

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/**
 * Copyright (C) 2014 Karlsruhe Institute of Technology 
 *
 * 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.
 */
/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package edu.kit.dama.ui.simon.impl;

import edu.kit.dama.ui.simon.exceptions.ProbeConfigurationException;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import org.apache.commons.configuration.PropertiesConfiguration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 * @author jejkal
 */
public class WebServerProbe extends AbstractProbe {

    private static Logger LOGGER = LoggerFactory.getLogger(WebServerProbe.class);
    private final String SERVICE_URL_KEY = "server.url";
    private final String CONNECTION_TIMEOUT_KEY = "timeout";
    private URL serverUrl = null;
    private int timeout = 5000;

    @Override
    public boolean checkProbe() {
        try {
            URLConnection con = serverUrl.openConnection();
            con.setConnectTimeout(timeout);
            con.connect();
            String header0 = con.getHeaderField(0);
            return header0 != null && header0.endsWith("200 OK");
        } catch (IOException ex) {
            LOGGER.error("Failed to check Web server probe", ex);
        }
        return false;
    }

    @Override
    public void configureProbe(PropertiesConfiguration pProperties) throws ProbeConfigurationException {
        LOGGER.debug("Configuring WebServer probe...");

        String sServiceUrl = pProperties.getString(SERVICE_URL_KEY);
        if (sServiceUrl == null) {
            throw new ProbeConfigurationException("Property " + SERVICE_URL_KEY + " is missing.");
        } else {
            LOGGER.debug(" - Setting property {} to value {}", new Object[] { SERVICE_URL_KEY, sServiceUrl });
        }

        try {
            serverUrl = new URL(sServiceUrl);
        } catch (MalformedURLException ex) {
            throw new ProbeConfigurationException("The provided service URL " + sServiceUrl + " is invalid", ex);
        }

        String sTimeout = pProperties.getString(CONNECTION_TIMEOUT_KEY, "5000");
        try {
            timeout = Integer.parseInt(sTimeout);
            LOGGER.debug(" - Setting property {} to value {}", new Object[] { CONNECTION_TIMEOUT_KEY, timeout });
        } catch (NumberFormatException ex) {
            LOGGER.warn("Property " + CONNECTION_TIMEOUT_KEY
                    + " is not a valid integer number, using default value 5000.");
            timeout = 5000;
        }

        LOGGER.debug("WebServer probe successfully configured.");
    }

    @Override
    public String[] getConfigurationPropertyKeys() {
        return new String[] { SERVICE_URL_KEY, CONNECTION_TIMEOUT_KEY };
    }

    @Override
    public String getConfigurationPropertyDescription(String pKey) {
        if (SERVICE_URL_KEY.equals(pKey)) {
            return "The URL of the Web server to test, e.g. http://localhost/";
        } else if (CONNECTION_TIMEOUT_KEY.equals(pKey)) {
            return "The timeout in milliseconds until the probe is marked as FAILED. (Default: 1000 ms)";
        }
        return "Unknown property";
    }
}