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Process does not exit when launched from Java

I am launching WebTorrent-CLI from within my Java application as a separate process. I am using zt-exec for managing the process. When WebTorrent is launched with the following command, it is supposed to exit after the file at given index (value of --select) has been downloaded.
"D:\downloadmanager\node\webtorrent.cmd" download "magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel" --select 0 --out "D://nf/"
As expected, webtorrent-cli does exit after downloading 0th file when the command above is used to launch it from command line. But when I try the same from within my Java app, it completely ignores the --select option and continues downloading other files in the torrent.
Basically, when launched as a process from Java, webtorrent ignores all the options set (--select, --out or whatever). I should mention that there is nothing wrong with the library because recently I've tried replacing it with commons-exec and that solved nothing. Also, to make sure that the right command is passed while starting the process, I'm printing the command right before calling executor.start(). The command above is copied from the output retrieved from printing the command before the process starts.
This is how the process is started:
#Override
public synchronized void start() throws IOException {
if (mWasDownloadStarted || mWasDownloadFinished) return;
mExec.getCommand().listIterator().forEachRemaining(s -> {
System.out.print(s + " ");
});
mExec.start();
setProcessId();
mWasDownloadStarted = true;
mWasDownloadStopped = false;
}
This is how the command is prepared:
private String buildCommand() {
List <String> command = new ArrayList<>();
command.add("\"" + mManager.mWTLocation + "\"");
command.add("download");
command.add("\"" + mManager.mMagnetUrl + "\"");
if (mManager.mFileIndex >= 0) {
command.add("--select " + mManager.mFileIndex);
}
if (mManager.mSaveTo != null) {
command.add("--out \"" + mManager.mSaveTo + "\"");
}
mManager.mExec.command(command);
String cmdStr = "";
for (String s : command) {
cmdStr = cmdStr.concat(s + " ");
}
return cmdStr.trim();
}
What might be wrong?

Okay, so I was able to fix this issue.
The / character following the path specified as value of --out was causing the problem. In order to fix this, I added a line in node_modules/webtorrent-cli/bin/cmd.js to print the arguments passed to webtorrent:
console.log(process.argv)
With the /, output of this line was something like the following:
[ 'D:\\downloadmanager\\node\\node.exe',
'D:\\downloadmanager\\node\\node_modules\\webtorrent-cli\\bin\\cmd.js',
'download',
'magnet:?xt=urn:btih:08ada5a7a6183aae1e09d831df6748d566095a10&dn=Sintel',
'--select',
'0',
'--out',
'D:\\nf"' ]
Note the " that is included in the path after D:\\nf. When / is removed from the path, the quote disappears and webtorrent behaves as expected.
I doubt that this is a bug in webtorrent. I think zt-exec (or maybe I) was doing something stupid.
Somewhat unrelated, but I think I should also mention that I had to enclose every value for each option with quotes, even the index, to get rid of other nasty errors (e.g.: Error 87, the parameter is incorrect)

UltiSnips expand java package

I want to be able to write a vim snippet that automatically turns into the required package.
E.g. expanding pkg while inside of .../com/theonlygust/project/Main.java would become
package com.theonlygusti.project;
I think the ways to do this are to either: read up the directory tree until seeing a TLD directory name (com, io, net, etc.) and then use the encountered directory names to build the package string, or to look up the directory tree for the pom.xml and find the package from there.
I learned about python interpolation.
I'm now trying this:
snippet pkg "Create package" b
package `!p
import os
from xml.etree import ElementTree
def get_package_name(pom_file_path):
namespaces = {'xmlns' : 'http://maven.apache.org/POM/4.0.0'}
tree = ElementTree.parse(pom_file_path)
root = tree.getroot()
groupId = root.find(".//xmlns:groupId", namespaces=namespaces)
artifactId = root.find(".//xmlns:artifactId", namespaces=namespaces)
return groupId.text + '.' + artifactId.text
def find_nearest_pom():
absolute_path = os.path.abspath(os.path.dirname('__file__')).split("/")
pom_dir_index = -1
# Find index of 'base_dir_name' element
while not os.path.isfile('/'.join(absolute_path[:pom_dir_index]) + '/pom.xml'):
pom_dir_index -= 1
return '/'.join(absolute_path[:pom_dir_index]) + '/pom.xml'
snip.rv = get_package_name(find_nearest_pom())`;
endsnippet
But I get the error
Name __file__ does not exist
And os.getcwd() doesn't work because that returns the directory from which vim was opened, not the directory that contains the current buffer.
I had a look at the snip object because I know it provides snip.fn to get the filename, but I couldn't find out if it provides the current file's directory.
Nevermind, finally learned that UltiSnips sets a global variable "path"

UltiSnips stores Java snippets in java.snippets, which on my machine is ~/.vim/bundle/vim-snippets/UltiSnips/java.snippets (I am usinghonza/vim-snippets` as well).
Snippets for Java are implemented using Python, so I have implemented the snippet below using Python as well (you can do it using multiple languages in UltiSnips).
There is already a snippet for package, which adds simply "package" word followed with a placeholder:
snippet pa "package" b
package $0
endsnippet
Let's create a pad snippet that will automatically insert package name, based on the directory chain, instead of the $0 placeholder:
snippet pad "package" b
package `!p
def get_package_string(base_dir_name):
import os
# Get absolute path of the package (without filename)
absolute_path = os.getcwd().split("/")
src_dir_index = 0
# Find index of 'base_dir_name' element
while absolute_path[src_dir_index] != base_dir_name:
src_dir_index+=1
# Create a 'package ' string, joining with dots
package_string = ".".join(absolute_path[src_dir_index+1:])
return package_string
# snip.rv is UltiSnips' return value we want to paste between ``
snip.rv = get_package_string("java")`
endsnippet
Note that this solution is based on the fact that in many Java projects, there is an src directory with main/java and test/java directories in it and you are editing one of the files in java directory (e.g. for src/main/com/google/common it will return com.google.common). You may need to modify this to be more flexible.
You can find more information about creating snippets in screencasts linked in its README.

I use a combination of the file path and the groupId and the artifactId from the nearest pom.xml (upwards)
global !p
import os
from xml.etree import ElementTree
def get_package_name(pom_file_path):
namespaces = {'xmlns' : 'http://maven.apache.org/POM/4.0.0'}
tree = ElementTree.parse(pom_file_path)
root = tree.getroot()
groupId = root.find(".//xmlns:groupId", namespaces=namespaces)
artifactId = root.find(".//xmlns:artifactId", namespaces=namespaces)
return groupId.text + '.' + artifactId.text
def find_nearest_pom():
current_file_dir = '/'.join((os.getcwd() + ('/' if os.getcwd()[-1] != '/' else '') + path).split('/')[:-1])
absolute_path = current_file_dir.split("/")
pom_dir_index = -1
if os.path.isfile('/'.join(absolute_path) + '/pom.xml'):
return '/'.join(absolute_path) + '/pom.xml'
# Find index of 'base_dir_name' element
while not os.path.isfile('/'.join(absolute_path[:pom_dir_index]) + '/pom.xml'):
pom_dir_index -= 1
return '/'.join(absolute_path[:pom_dir_index]) + '/pom.xml'
def get_file_package():
current_file_location = '.'.join((os.getcwd() + ('/' if os.getcwd()[-1] != '/' else '') + path).split('/')[:-1])
package = get_package_name(find_nearest_pom())
return package + current_file_location.split(package)[1]
endglobal
snippet pkg "package" b
package `!p snip.rv = get_file_package()`;
endsnippet

How to resolve "Error: long vectors not supported yet: qap_encode.c:36"?

I am trying to connect java with R using Rserve
Java: 1.8.0_151
R: 3.5.0
OS: Mac 10.13.4 HighSierra
To connect R with Java, I typed the following on RStudio
install.packages("Rserve")
library(Rserve)
Rserve(args="--no-save")
things went smooth and I was so happy about it.
Then I jumped back to Java (Java Eclipse so to speak) and continued typing. Here is what I've done on Eclipse
package rserve;
import org.rosuda.REngine.REXPMismatchException;
import org.rosuda.REngine.REngineException;
import org.rosuda.REngine.Rserve.RConnection;
import org.rosuda.REngine.Rserve.RserveException;
public class WordCloud1 {
public static void main(String[] args) throws REngineException,
REXPMismatchException {
RConnection c = new RConnection();
String path = "/Users/JinhoShin/Desktop/study/R/r_temp2";
String file = "seoul_new.txt";
c.parseAndEval("library(KoNLP)");
c.parseAndEval("useSejongDic()");
c.parseAndEval("library(wordcloud)");
c.parseAndEval("library(RColorBrewer)");
c.parseAndEval("setwd('" + path + "')");
c.parseAndEval("data1=readLines('" + file + "')");
c.parseAndEval("data2 = sapply(data1,extractNoun,USE.NAMES=F)");
c.parseAndEval("data3 = unlist(data2)");
c.parseAndEval("data3=gsub('seoul','',data3)");
c.parseAndEval("data3=gsub('request','',data3)");
c.parseAndEval("data3=gsub('place','',data3)");
c.parseAndEval("data3=gsub('transportation','',data3)");
c.parseAndEval("data3=gsub(' ','',data3)");
c.parseAndEval("data3=gsub('-','',data3)");
c.parseAndEval("data3=gsub('OO','',data3)");
c.parseAndEval("write(unlist(data3),'seoul_2.txt')");
c.parseAndEval("data4 = read.table('seoul_2.txt')"); ########this is what blows me up
c.parseAndEval("wordcount=table(data4)");
c.parseAndEval("palete = brewer.pal(9,'Set3')");
c.parseAndEval(
"wordcloud(names(wordcount),freq = wordcount,scale=c(5,1),rot.per=0.25, min.freq = 1," +
" random.order=F, random.color = T, colors=palete)");
c.parseAndEval("savePlot('0517seoul.png', type = 'png')");
c.parseAndEval("dev.off()");
c.close();
}
}
as you notice from the code
c.parseAndEval("data4 = read.table('seoul_2.txt')"); => at rserve.WordCloud1.main(WordCloud1.java:30)
I have no idea why it can't read my text file despite the fact that it could write that file.
This is what Java Eclipse console keeps showing me
Exception in thread "main" org.rosuda.REngine.REngineException: eval failed
at org.rosuda.REngine.Rserve.RConnection.parseAndEval(RConnection.java:499)
at org.rosuda.REngine.REngine.parseAndEval(REngine.java:108)
at rserve.WordCloud1.main(WordCloud1.java:30)
Caused by: org.rosuda.REngine.Rserve.RserveException: eval failed
at org.rosuda.REngine.Rserve.RConnection.eval(RConnection.java:261)
at org.rosuda.REngine.Rserve.RConnection.parseAndEval(RConnection.java:497)
... 2 more
and this is what RStudio keeps showing me
Error: long vectors not supported yet: qap_encode.c:36
Fatal error: unable to initialize the JIT
I tried everything I could do to resolve this issue, but still I am on the same spot.

Ensure Install4j Uses only its bundled jre and never Java found by path

question
How can I ensure my install4j installer always finds only its java?
Can I create a top level installer which installs JRE to tmp, sets env variables and then starts the actual installer?
Can I load a vm file during installation?
problem
Install4j finds java 1.7 during install which impacts custom code preventing successful installation. I see found java7 prior to file deployment - ok expected given the JRE hasn't yet been unpacked.
evidence
I created a simple installer and see the following:
BEFORE
PATH=/opt/tools/Java/jdk1.7.0_79/bin:...
JAVA_HOME=/opt/tools/Java/jdk1.7.0_79
...
ENV [JAVA_HOME] /opt/tools/Java/jdk1.7.0_79
ENV [PATH] /opt/tools/Java/jdk1.7.0_79/bin:...
installer details
envTest.install4j
Optional customer install script reporting found java prior at execution start
echo BEFORE
echo PATH=$PATH
echo JAVA_HOME=$JAVA_HOME
echo Version: java -version
Run script reporting env after installer deployed jre
`
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import java.util.TreeMap;
Map<String, String> envMap = System.getenv();
SortedMap<String, String> sortedEnvMap = new TreeMap<String, String>(envMap);
Set<String> keySet = sortedEnvMap.keySet();
for (String key : keySet) {
String value = envMap.get(key);
Util.logInfo(this,"ENV [" + key + "] " + value);
}
return true;

Actually, this turned our to be a problem with my custom code. The custom code launches an install4j generated executable via java. When launched on command line with wrong java found first, the launcher uses only its own java. When launched from my extension it fails.
Solution - set java in my extension:
private File getInstalledJREDir() {
return new File(installationDir, "jre");
}
private String addJREToFrontOfPathVar() {
File jreBinDir = new File(getInstalledJREDir(), "bin");
String path = System.getenv().get("PATH");
if (null == path) {
path = jreBinDir.getAbsolutePath();
} else {
path = jreBinDir.getAbsolutePath() + File.pathSeparator + path;
}
return path;
}
/**
* Start Laucnher and block until it starts or timeout reached
* #throws AutoRunException
*/
public void run() throws AutoRunException, IOException, InterruptedException {
notifier.setPhase("Starting Agent");
// Set Directories
File dataDir = new File(installationDir.getParentFile(), "data-agent");
File agentLog = new File(logDir,"agent.log");
if (! isWindows()) {
File agent = new File(installationDir, "bin/launcherExecutable");
CmdExecutor ce = new CmdExecutor(agent, agentLog);
// Ensure our installed JRE found 1st - PLAT-38833
ce.updateEnvironmentVariable("JAVA_HOME", getInstalledJREDir().getAbsolutePath());
ce.updateEnvironmentVariable("PATH", addJREToFrontOfPathVar());
ce.setWorkingDir(installationDir);
ce.setArgLine(String.format("--datadir %s", dataDir.getAbsolutePath()));
notifier.logInfo("Starting " + agent + " with " + ce.getArgLine());
if (! ce.run(true) ) {
throw new AutoRunException("Agent failed to start " + ce.getOutput());
}

JavaScript ScriptEngine isn't working within Google App Engine for Java (GAE/J)

I am having an issue where I always get a 0 value returned when I try to use the ScriptEngine eval. By using Logger, I was able to determine that there are NullPointerExceptions being generated. After further inspection, it appears that GAE doesn't always return a valid script engine (if ever), because it throws an exception when you try to use it.
My code looks like:
public double myEval(String JsFormulaStr ) {
double solutionValue = 0;
ScriptEngineManager mgr = new ScriptEngineManager();
ScriptEngine eng = mgr.getEngineByName("JavaScript");
if(eng == null) { // Added this block of code to prevent java.lang.NullPointerException...
log.severe("Unable to get Script Engine." );
return 0;
}
try {
Object jsResults = eng.eval(JsFormulaStr);
solutionValue = Double.parseDouble(jsResults.toString());
return solutionValue;
} catch(Exception e) {
log.severe("[ERROR] in getCalculatedSolution_FromJS_ToDouble()::\n\t" +
"Formula String is: " + JsFormulaStr + "\n\t" + e);
return 0;
}
}
Everything works fine if I run it locally as a WebApp (Both in Eclipse & Netbeans. And within Tomcat & Glassfish 4.0).
Some of the strings which I tried to eval:
62.0 / 100
0.0 * 352.0
(0 - 428) * 1000
(0 - 597) * 1000
73.0 / 100
NOTE: The 0's or 0.0's are from other evaluations which have failed in previous calls. Since this function returns 0 on error.
According to Google's JRE Class Whitelist, the ScriptEngineManager and ScriptEngine classes are allowed. So I don't understand why it isn't working as expected.
Any suggestions?
Thanks in advance,
Randy

I've hit the same problem. Although the classes are whitelisted, it seems like their functionality is limited on App Engine. The code works fine on your local machine but fails when deployed to App Engine as there aren't any script engines available (hence the NullPointerException).
Luckily, you can do the same thing using the Rhino engine.
Note: this example builds on that given by Harsha R in https://stackoverflow.com/a/19828128/578821
Download the Rhino Jar and add js.jar to your classpath (you only need js-14.jar if you're using Java 1.4).
/* Example 1: Running a JavaScript function (taken from examples) */
String script = "function abc(x,y) {return x+y;}";
Context context = Context.enter();
try {
ScriptableObject scope = context.initStandardObjects();
Scriptable that = context.newObject(scope);
Function fct = context.compileFunction(scope, script, "script", 1, null);
Object result = fct.call(context, scope, that, new Object[] { 2, 3 });
System.out.println(Context.jsToJava(result, int.class));
}
finally {
Context.exit();
}
/* Example 2: execute a JavaScript statement */
script = "3 + 2 * (4*5)";
context = Context.enter();
try{
Scriptable scope = context.initStandardObjects();
Object result = context.evaluateString(scope, script, "<cmd>", 1, null);
System.out.println(result);
}
finally{
Context.exit();
}