org.openflamingo.engine.util.VersionConfigurer.java Source code

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Here is the source code for org.openflamingo.engine.util.VersionConfigurer.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.openflamingo.engine.util;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.util.Log4jWebConfigurer;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import java.io.InputStream;
import java.util.Enumeration;
import java.util.Map;
import java.util.Properties;
import java.util.Set;

/**
 * Application Version?  Configurer.
 *
 * @author Byoung Gon, Kim
 * @since 0.5
 */
public class VersionConfigurer implements javax.servlet.ServletContextListener {

    /**
     * SLF4J Logging
     */
    private Logger logger = LoggerFactory.getLogger(VersionConfigurer.class);

    private static final long MEGA_BYTES = 1024 * 1024;

    private static final String UNKNOWN = "Unknown";

    /**
     * Notification that the web application initialization
     * process is starting.
     * All ServletContextListeners are notified of context
     * initialization before any filter or servlet in the web
     * application is initialized.
     *
     * @param servletContextEvent {@link javax.servlet.ServletContextEvent}
     */
    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
        Log4jWebConfigurer.initLogging(servletContextEvent.getServletContext());

        Properties properties = new Properties();
        ServletContext context = servletContextEvent.getServletContext();
        InputStream inputStream = null;
        try {
            inputStream = context.getResourceAsStream("/WEB-INF/version.properties");
            properties.load(inputStream);
        } catch (Exception ex) {
            throw new IllegalArgumentException("Cannot load a '/WEB/INF/version.properties' file.", ex);
        } finally {
            IOUtils.closeQuietly(inputStream);
        }

        StringBuilder builder = new StringBuilder();

        printHeader(builder, "Application Information");
        Properties appProps = new Properties();
        appProps.put("Application", "Flamingo Workflow Engine");
        appProps.put("Version", properties.get("version"));
        appProps.put("Build Date", properties.get("build.timestamp"));
        appProps.put("Build Number", properties.get("build.number"));
        appProps.put("Revision Number", properties.get("revision.number"));
        appProps.put("Build Key", properties.get("build.key"));

        if (context != null) {
            appProps.put("Application Server", context.getServerInfo() + " - Servlet API "
                    + context.getMajorVersion() + "." + context.getMinorVersion());
        }

        Properties systemProperties = System.getProperties();
        appProps.put("Java Version", systemProperties.getProperty("java.version", UNKNOWN) + " - "
                + systemProperties.getProperty("java.vendor", UNKNOWN));
        appProps.put("Current Working Directory", systemProperties.getProperty("user.dir", UNKNOWN));

        print(builder, appProps);

        printHeader(builder, "JVM Heap Information");

        Properties memPros = new Properties();
        final Runtime rt = Runtime.getRuntime();
        final long maxMemory = rt.maxMemory() / MEGA_BYTES;
        final long totalMemory = rt.totalMemory() / MEGA_BYTES;
        final long freeMemory = rt.freeMemory() / MEGA_BYTES;
        final long usedMemory = totalMemory - freeMemory;

        memPros.put("Maximum Allowable Memory", maxMemory + "MB");
        memPros.put("Total Memory", totalMemory + "MB");
        memPros.put("Free Memory", freeMemory + "MB");
        memPros.put("Used Memory", usedMemory + "MB");

        print(builder, memPros);

        printHeader(builder, "Java System Properties");
        Properties sysProps = new Properties();
        for (final Map.Entry<Object, Object> entry : systemProperties.entrySet()) {
            sysProps.put(entry.getKey(), entry.getValue());
        }

        print(builder, sysProps);

        printHeader(builder, "System Environments");
        Map<String, String> getenv = System.getenv();
        Properties envProps = new Properties();
        Set<String> strings = getenv.keySet();
        for (String key : strings) {
            String message = getenv.get(key);
            envProps.put(key, message);
        }

        print(builder, envProps);

        logger.info("=================================================");
        logger.info(" Flamingo Workflow Engine starting...");
        logger.info("=================================================\n{}", builder.toString());
    }

    /**
     * ?? .
     *
     * @param builder {@link StringBuilder}
     * @param message  
     */
    private void printHeader(StringBuilder builder, String message) {
        builder.append(
                org.slf4j.helpers.MessageFormatter.format("\n== {} =====================\n", message).getMessage())
                .append("\n");
    }

    /**
     * Key Value ?? .
     *
     * @param builder {@link StringBuilder}
     * @param props    Key Value ?
     */
    private void print(StringBuilder builder, Properties props) {
        int maxLength = getMaxLength(props);
        Enumeration<Object> keys = props.keys();
        while (keys.hasMoreElements()) {
            String key = (String) keys.nextElement();
            String value = props.getProperty(key);
            builder.append("  ").append(key).append(getCharacter(maxLength - key.getBytes().length, " "))
                    .append(" : ").append(value).append("\n");
        }
    }

    /**
     * ?  Key Value ?   Key ?? ? .
     *
     * @param props {@link java.util.Properties}
     * @return Key ? ?   ?? ?
     */
    private int getMaxLength(Properties props) {
        Enumeration<Object> keys = props.keys();
        int maxLength = -1;
        while (keys.hasMoreElements()) {
            String key = (String) keys.nextElement();
            if (maxLength < 0) {
                maxLength = key.getBytes().length;
            } else if (maxLength < key.getBytes().length) {
                maxLength = key.getBytes().length;
            }
        }
        return maxLength;
    }

    /**
     *  ? ? ?? .
     *
     * @param size      ??  
     * @param character ??    ?. ? ??.
     * @return ?
     */
    private static String getCharacter(int size, String character) {
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < size; i++) {
            builder.append(character);
        }
        return builder.toString();
    }

    /**
     * Notification that the servlet context is about to be shut down.
     * All servlets and filters have been destroy()ed before any
     * ServletContextListeners are notified of context
     * destruction.
     *
     * @param servletContextEvent {@link javax.servlet.ServletContextEvent}
     */
    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        Log4jWebConfigurer.shutdownLogging(servletContextEvent.getServletContext());
    }
}