com.threerings.getdown.util.LaunchUtil Maven / Gradle / Ivy
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//
// Getdown - application installer, patcher and launcher
// Copyright (C) 2004-2016 Getdown authors
// https://github.com/threerings/getdown/blob/master/LICENSE
package com.threerings.getdown.util;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintStream;
import java.util.Locale;
import static com.threerings.getdown.Log.log;
/**
* Useful routines for launching Java applications from within other Java
* applications.
*/
public class LaunchUtil
{
/** The directory into which a local VM installation should be unpacked. */
public static final String LOCAL_JAVA_DIR = "java_vm";
/**
* Writes a version.txt file into the specified application directory and
* attempts to relaunch Getdown in that directory which will cause it to upgrade to the newly
* specified version and relaunch the application.
*
* @param appdir the directory in which the application is installed.
* @param getdownJarName the name of the getdown jar file in the application directory. This is
* probably getdown-pro.jar or getdown-retro-pro.jar if you are using
* the results of the standard build.
* @param newVersion the new version to which Getdown will update when it is executed.
*
* @return true if the relaunch succeeded, false if we were unable to relaunch due to being on
* Windows 9x where we cannot launch subprocesses without waiting around for them to exit,
* reading their stdout and stderr all the while. If true is returned, the application may exit
* after making this call as it will be upgraded and restarted. If false is returned, the
* application should tell the user that they must restart the application manually.
*
* @exception IOException thrown if we were unable to create the version.txt file
* in the supplied application directory. If the version.txt file cannot be created, restarting
* Getdown will not cause the application to be upgraded, so the application will have to
* resort to telling the user that it is in a bad way.
*/
public static boolean updateVersionAndRelaunch (
File appdir, String getdownJarName, String newVersion)
throws IOException
{
// create the file that instructs Getdown to upgrade
File vfile = new File(appdir, "version.txt");
try (PrintStream ps = new PrintStream(new FileOutputStream(vfile))) {
ps.println(newVersion);
}
// make sure that we can find our getdown.jar file and can safely launch children
File pro = new File(appdir, getdownJarName);
if (mustMonitorChildren() || !pro.exists()) {
return false;
}
// do the deed
String[] args = new String[] {
getJVMPath(appdir), "-jar", pro.toString(), appdir.getPath()
};
log.info("Running " + StringUtil.join(args, "\n "));
try {
Runtime.getRuntime().exec(args, null);
return true;
} catch (IOException ioe) {
log.warning("Failed to run getdown", ioe);
return false;
}
}
/**
* Reconstructs the path to the JVM used to launch this process.
*/
public static String getJVMPath (File appdir)
{
return getJVMPath(appdir, false);
}
/**
* Reconstructs the path to the JVM used to launch this process.
*
* @param windebug if true we will use java.exe instead of javaw.exe on Windows.
*/
public static String getJVMPath (File appdir, boolean windebug)
{
// first look in our application directory for an installed VM
String vmpath = checkJVMPath(new File(appdir, LOCAL_JAVA_DIR).getAbsolutePath(), windebug);
// then fall back to the VM in which we're already running
if (vmpath == null) {
vmpath = checkJVMPath(System.getProperty("java.home"), windebug);
}
// then throw up our hands and hope for the best
if (vmpath == null) {
log.warning("Unable to find java [appdir=" + appdir +
", java.home=" + System.getProperty("java.home") + "]!");
vmpath = "java";
}
// Oddly, the Mac OS X specific java flag -Xdock:name will only work if java is launched
// from /usr/bin/java, and not if launched by directly referring to /bin/java,
// even though the former is a symlink to the latter! To work around this, see if the
// desired jvm is in fact pointed to by /usr/bin/java and, if so, use that instead.
if (isMacOS()) {
try {
File localVM = new File("/usr/bin/java").getCanonicalFile();
if (localVM.equals(new File(vmpath).getCanonicalFile())) {
vmpath = "/usr/bin/java";
}
} catch (IOException ioe) {
log.warning("Failed to check Mac OS canonical VM path.", ioe);
}
}
return vmpath;
}
/**
* Upgrades Getdown by moving an installation managed copy of the Getdown jar file over the
* non-managed copy (which would be used to run Getdown itself).
*
* If the upgrade fails for a variety of reasons, warnings are logged but no other actions
* are taken. There's not much else one can do other than try again next time around.
*/
public static void upgradeGetdown (File oldgd, File curgd, File newgd)
{
// we assume getdown's jar file size changes with every upgrade, this is not guaranteed,
// but in reality it will, and it allows us to avoid pointlessly upgrading getdown every
// time the client is updated which is unnecessarily flirting with danger
if (!newgd.exists() || newgd.length() == curgd.length()) {
return;
}
log.info("Updating Getdown with " + newgd + "...");
// clear out any old getdown
if (oldgd.exists()) {
FileUtil.deleteHarder(oldgd);
}
// now try updating using renames
if (!curgd.exists() || curgd.renameTo(oldgd)) {
if (newgd.renameTo(curgd)) {
FileUtil.deleteHarder(oldgd); // yay!
try {
// copy the moved file back to getdown-dop-new.jar so that we don't end up
// downloading another copy next time
FileUtil.copy(curgd, newgd);
} catch (IOException e) {
log.warning("Error copying updated Getdown back: " + e);
}
return;
}
log.warning("Unable to renameTo(" + oldgd + ").");
// try to unfuck ourselves
if (!oldgd.renameTo(curgd)) {
log.warning("Oh God, why dost thee scorn me so.");
}
}
// that didn't work, let's try copying it
log.info("Attempting to upgrade by copying over " + curgd + "...");
try {
FileUtil.copy(newgd, curgd);
} catch (IOException ioe) {
log.warning("Mayday! Brute force copy method also failed.", ioe);
}
}
/**
* Returns true if, on this operating system, we have to stick around and read the stderr from
* our children processes to prevent them from filling their output buffers and hanging.
*/
public static boolean mustMonitorChildren ()
{
String osname = System.getProperty("os.name", "").toLowerCase(Locale.ROOT);
return (osname.indexOf("windows 98") != -1 || osname.indexOf("windows me") != -1);
}
/**
* Returns true if we're running in a JVM that identifies its operating system as Windows.
*/
public static final boolean isWindows () { return _isWindows; }
/**
* Returns true if we're running in a JVM that identifies its operating system as MacOS.
*/
public static final boolean isMacOS () { return _isMacOS; }
/**
* Returns true if we're running in a JVM that identifies its operating system as Linux.
*/
public static final boolean isLinux () { return _isLinux; }
/**
* Checks whether a Java Virtual Machine can be located in the supplied path.
*/
protected static String checkJVMPath (String vmhome, boolean windebug)
{
String vmbase = vmhome + File.separator + "bin" + File.separator;
String vmpath = vmbase + "java";
if (new File(vmpath).exists()) {
return vmpath;
}
if (!windebug) {
vmpath = vmbase + "javaw.exe";
if (new File(vmpath).exists()) {
return vmpath;
}
}
vmpath = vmbase + "java.exe";
if (new File(vmpath).exists()) {
return vmpath;
}
return null;
}
/** Flag indicating that we're on Windows; initialized when this class is first loaded. */
protected static boolean _isWindows;
/** Flag indicating that we're on MacOS; initialized when this class is first loaded. */
protected static boolean _isMacOS;
/** Flag indicating that we're on Linux; initialized when this class is first loaded. */
protected static boolean _isLinux;
static {
try {
String osname = System.getProperty("os.name");
osname = (osname == null) ? "" : osname;
_isWindows = (osname.indexOf("Windows") != -1);
_isMacOS = (osname.indexOf("Mac OS") != -1 ||
osname.indexOf("MacOS") != -1);
_isLinux = (osname.indexOf("Linux") != -1);
} catch (Exception e) {
// can't grab system properties; we'll just pretend we're not on any of these OSes
}
}
}