JRE32Downloader.java

package rs.toolkit.util.jre;

import rs.toolkit.util.OperatingSystem;
import rs.toolkit.util.io.Internet;
import rs.toolkit.util.io.InternetCallback;
import rs.toolkit.util.io.Untar;

import java.io.File;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.StandardCopyOption;
import java.util.List;
import java.util.function.Consumer;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @author Tyler Sedlar
 * @since 3/19/2016
 */
public class JRE32Downloader {

    private static final String BASE_URL = "http://download.oracle.com/otn-pub/java/jdk/%s-b02/jre-%s-%s-%s.tar.gz";
    private static final String DOWNLOAD_URL = "http://www.java.com/en/download/manual.jsp";

    private static final Pattern VERSION_PATTERN = Pattern.compile("Recommended Version (\\d+) Update (\\d+)");

    private static final Consumer<HttpURLConnection> LICENSE_CONSUMER =
        (connection) -> connection.setRequestProperty("Cookie", "oraclelicense=a;");

    public enum JavaSystem {
        WINDOWS("windows", "i586"),
        LINUX("linux", "i586"),
        MAC("macosx", "x64");

        public final String system, arch;

        JavaSystem(String system, String arch) {
            this.system = system;
            this.arch = arch;
        }

        public String resolveURL(String version) {
            return String.format(BASE_URL, version, version, system, arch);
        }
    }

    public static boolean download(JavaSystem system, String version, File target) {
        if (target.exists()) {
            return true;
        }
        URL url = Internet.resolveURL(system.resolveURL(version), LICENSE_CONSUMER);
        return url != null && Internet.download(url.toExternalForm(), target.getAbsolutePath(), new InternetCallback() {
            public void onDownload(int percent) {
                System.out.println("JRE Install: " + percent + "%");
            }
        }) != null;
    }

    public static String latest() {
        String source = Internet.readFully(DOWNLOAD_URL);
        if (source != null) {
            Matcher matcher = VERSION_PATTERN.matcher(source);
            if (matcher.find()) {
                return (matcher.group(1) + "u" + matcher.group(2));
            }
        }
        return null;
    }

    public static boolean downloadAndExtract(String version, File target, File directory) {
        if (directory.exists()) {
            return true;
        }
        String latest = (version != null ? version : latest());
        JavaSystem system = JavaSystem.LINUX;
        if (OperatingSystem.get() == OperatingSystem.WINDOWS) {
            system = JavaSystem.WINDOWS;
        } else if (OperatingSystem.get() == OperatingSystem.MAC) {
            system = JavaSystem.MAC;
        }
        if (download(system, latest, target)) {
            List<File> files = Untar.process(target);
            if (files != null) {
                try {
                    Files.delete(target.toPath());
                } catch (IOException e) {
                    e.printStackTrace();
                    return false;
                }
                for (File file : files) {
                    if (file.isDirectory()) {
                        if (file.getName().startsWith("jre")) {
                            try {
                                Files.move(file.toPath(), directory.toPath(), StandardCopyOption.REPLACE_EXISTING);
                            } catch (IOException e) {
                                e.printStackTrace();
                                return false;
                            }
                        }
                    }
                }
                return true;
            }
        }
        return false;
    }

    public static boolean downloadAndExtract(File target, File directory) {
        return downloadAndExtract(null, target, directory);
    }
}