javarestart.Utils.java Source code

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Here is the source code for javarestart.Utils.java

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/*
 * Copyright (c) 2013-2014, Nikita Lipsky, Excelsior LLC.
 *
 *  Java ReStart is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Java ReStart is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Java ReStart.  If not, see <http://www.gnu.org/licenses/>.
 *
*/
package javarestart;

import org.json.simple.JSONObject;
import org.json.simple.JSONValue;

import java.io.*;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.Charset;

public class Utils {

    static File fetchResourceToTempFile(String resName, String resExt, InputStream from) {
        File temp;
        try {
            temp = File.createTempFile(resName, resExt);
        } catch (IOException e) {
            return null;
        }
        temp.deleteOnExit();
        try (BufferedOutputStream os = new BufferedOutputStream(new FileOutputStream(temp))) {
            copy(from, os);
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
        return temp;
    }

    static File fetchResourceToTempFile(String resName, String resExt, URL from) {
        try {
            return fetchResourceToTempFile(resName, resExt, from.openStream());
        } catch (IOException e) {
            e.printStackTrace();
            return null;
        }
    }

    public static void copy(InputStream in, OutputStream out) throws IOException {
        int nRead;
        byte[] data = new byte[16384];

        while ((nRead = in.read(data, 0, data.length)) != -1) {
            out.write(data, 0, nRead);
        }
    }

    static void copy(InputStream in, OutputStream out, int length) throws IOException {
        int nRead;
        byte[] data = new byte[16384];

        while ((nRead = in.read(data, 0, Math.min(length, data.length))) != -1) {
            out.write(data, 0, nRead);
            length -= nRead;
            if (length == 0) {
                return;
            }
        }
    }

    public static String readAsciiLine(InputStream in) throws IOException {
        StringBuilder sb = new StringBuilder();
        boolean prevCR = false;
        while (true) {
            int b = in.read();
            if (b == -1) {
                return sb.toString();
            }
            if (b == 0xD) {
                prevCR = true;
            } else if ((b == 0xA) && prevCR) {
                return sb.toString();
            } else {
                sb.append((char) b);
                prevCR = false;
            }
        }
    }

    public static JSONObject getJSON(final String url) throws IOException {
        return getJSON(new URL(url));
    }

    public static JSONObject getJSON(final URL url) throws IOException {
        return (JSONObject) JSONValue.parse(getText(url));
    }

    private static String getText(final URL url) throws IOException {
        final URLConnection connection = url.openConnection();
        try (LineNumberReader in = new LineNumberReader(
                new InputStreamReader(connection.getInputStream(), Charset.forName("UTF-8")))) {

            final StringBuilder response = new StringBuilder();
            String inputLine;
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }

            return response.toString();
        }
    }

}