com.kappaware.logtrawler.Utils.java Source code

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Here is the source code for com.kappaware.logtrawler.Utils.java

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/*
 * Copyright (C) 2016 BROADSoftware
 *
 * 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.kappaware.logtrawler;

import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Calendar;
import java.util.Date;

import javax.servlet.http.HttpServletResponse;
import javax.xml.bind.DatatypeConverter;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class Utils {
    static Log log = LogFactory.getLog(Utils.class);

    static public boolean isEquals(Object o1, Object o2) {
        if (o1 == null) {
            return o2 == null;
        } else {
            return o1.equals(o2);
        }
    }

    public static boolean isNullOrEmpty(String str) {
        return str == null || str.trim().length() == 0;
    }

    public static String toString(Object o) {
        return (o == null) ? null : o.toString();
    }

    public static void assertNotNull(Object val, String message, Object... params) {
        if (val == null) {
            String m = String.format(message, params);
            log.fatal(m);
            System.exit(1);
        }
    }

    public static void assertNull(Object val, String message, Object... params) {
        if (val != null) {
            String m = String.format(message, params);
            log.fatal(m);
            System.exit(1);
        }
    }

    // Http definition
    private static final String HEADER_PRAGMA = "Pragma";
    private static final String HEADER_EXPIRES = "Expires";
    private static final String HEADER_CACHE_CONTROL = "Cache-Control";

    public static void setCache(HttpServletResponse response, int cacheValue) {
        if (cacheValue == 0) {
            response.setHeader(HEADER_PRAGMA, "no-cache");
            // HTTP 1.0 header
            response.setDateHeader(HEADER_EXPIRES, 1L);
            // HTTP 1.1 header: "no-cache" is the standard value,
            // "no-store" is necessary to prevent caching on FireFox.
            response.setHeader(HEADER_CACHE_CONTROL, "no-cache");
            response.addHeader(HEADER_CACHE_CONTROL, "no-store");
            response.addHeader(HEADER_CACHE_CONTROL, "must-revalidate");
            response.addHeader(HEADER_CACHE_CONTROL, "post-check=0");
            response.addHeader(HEADER_CACHE_CONTROL, "pre-check=0");

        } else {
            response.setHeader(HEADER_CACHE_CONTROL, "public");
            long now = (new Date()).getTime();
            response.setDateHeader("Date", now);
            response.setDateHeader(HEADER_EXPIRES, now + (cacheValue * 1000L));
            // HTTP 1.1 header
            String headerValue = "max-age=" + Long.toString(cacheValue);
            response.setHeader(HEADER_CACHE_CONTROL, headerValue);
        }
    }

    public static String getHostname() {
        try {
            return InetAddress.getLocalHost().getHostName();
        } catch (UnknownHostException e) {
            log.error("Unable to find our hostname!");
            return "UNKNOW";
        }
    }

    /*
    private static String isoDateTimeFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ";
        
    public static String printIsoDateTime(Long ts) {
       if (ts != null) {
     SimpleDateFormat sdf = new SimpleDateFormat(isoDateTimeFormat.toString());
     return sdf.format(ts);
       } else {
     return null;
       }
    }
    */
    public static String printIsoDateTime(Long ts) {
        if (ts != null) {
            Calendar c = Calendar.getInstance();
            c.setTimeInMillis(ts);
            return DatatypeConverter.printDateTime(c);
        } else {
            return null;
        }
    }

    public static String toString(Throwable e) {
        StringBuffer sb = new StringBuffer();
        sb.append(e.toString());
        while ((e = e.getCause()) != null) {
            sb.append("\nCaused by:");
            sb.append(e.toString());
        }
        ;
        return sb.toString();
    }
}