uk.ac.gla.terrier.probos.Utils.java Source code

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Here is the source code for uk.ac.gla.terrier.probos.Utils.java

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/**
 * Copyright (c) 2016, University of Glasgow. All Rights Reserved.
 *
 * Cloudera, Inc. 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
 *
 * This software 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 uk.ac.gla.terrier.probos;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

import org.apache.commons.io.IOUtils;

public class Utils {

    public static String padRight(String s, int n) {
        if (s.length() > n)
            return s.substring(0, n - 1);
        return String.format("%1$-" + n + "s", s);
    }

    public static String padLeft(String s, int n) {
        if (s.length() > n)
            return s.substring(0, n - 1);
        return String.format("%1$" + n + "s", s);
    }

    public static String getHostname() throws IOException {
        String OS = System.getProperty("os.name").toLowerCase();
        //System.err.println(OS);
        String hostname = null;
        if (OS.indexOf("win") >= 0) {
            hostname = System.getenv("COMPUTERNAME");
            if (hostname == null)
                hostname = execReadToString("hostname");
        } else {
            if (OS.indexOf("nix") >= 0 || OS.indexOf("nux") >= 0 || OS.equals("mac os x")) {
                hostname = System.getenv("HOSTNAME");
                if (hostname == null)
                    hostname = execReadToString("hostname");
                if (hostname == null)
                    hostname = execReadToString("cat /etc/hostname");
            }
        }

        assert hostname != null;

        return hostname;
    }

    public static String execReadToString(String execCommand) throws IOException {
        Process proc = Runtime.getRuntime().exec(execCommand);
        try (InputStream stream = proc.getInputStream()) {
            try (Scanner s = new Scanner(stream).useDelimiter("\\A")) {
                return s.hasNext() ? s.next().trim() : "";
            }
        }
    }

    public static byte[] slurpBytes(final File file) throws IOException {
        BufferedInputStream bis = new BufferedInputStream(new FileInputStream(file));
        byte[] rtr = IOUtils.toByteArray(bis);
        bis.close();
        return rtr;
    }

    public static String[] slurpString(final File file) throws IOException {
        List<String> l = new ArrayList<String>();
        BufferedReader br = null;
        try {
            br = new BufferedReader(new FileReader(file));
            String line = null;
            while ((line = br.readLine()) != null) {
                l.add(line);
            }
        } finally {
            if (br != null)
                br.close();
        }

        return l.toArray(new String[l.size()]);
    }

    /* http://stackoverflow.com/questions/6118922/convert-seconds-value-to-hours-minutes-seconds-android-java */
    public static String makeTime(long seconds) {

        long hours = seconds / 3600;
        long minutes = (seconds % 3600) / 60;
        seconds = seconds % 60;

        return twoDigitString(hours) + ":" + twoDigitString(minutes) + ":" + twoDigitString(seconds);
    }

    public static String twoDigitString(long number) {
        if (number == 0) {
            return "00";
        }
        if (number / 10 == 0) {
            return "0" + number;
        }
        return String.valueOf(number);
    }

    public static long parseTime(String timeExpression) {
        /** format: [[hours:]minutes:]seconds[.milliseconds] */
        String[] parts = timeExpression.split(":");
        long duration = 0;
        if (parts.length == 1) {
            duration = Integer.parseInt(parts[0]);
        } else if (parts.length == 2) {
            duration = Integer.parseInt(parts[1]) + 60l * Integer.parseInt(parts[0]);
        } else if (parts.length == 3) {
            duration = Integer.parseInt(parts[2]) + 60l * Integer.parseInt(parts[1])
                    + 3600l * Integer.parseInt(parts[0]);
        } else {
            throw new IllegalArgumentException("Invalid time format:" + timeExpression);
        }
        return duration;
    }

    public static String readStringOrNull(DataInput in) throws IOException {
        if (!in.readBoolean())
            return null;
        return in.readUTF();
    }

    public static void writeStringOrNull(DataOutput out, String s) throws IOException {
        if (s == null) {
            out.writeBoolean(false);
        } else {
            out.writeBoolean(true);
            out.writeUTF(s);
        }
    }
}