Develop Reference

Spring Boot - Should I implement multi-threading to resolve this problem?

I've been working on some web project and one of its requests execute command line using Java Process.
This is the method.
#ResponseBody
#RequestMapping(value = "/startTest", method = RequestMethod.POST)
public String startTest(int test_id) {
...
String cmd = "..."
ProcessUtil pu = new ProcessUtil();
try {
pu.execute(cmd);
File file = new File(System.getProperty("user.dir")
+ "\\datas\\cypress\\videos\\examples\\main.spec.js.mp4");
File fileToMove = new File(
".\\\\datas\\\\results\\" + uitest.getTest_filename() + ".mp4");
file.renameTo(fileToMove);
return "success";
} catch (Exception e) {
return "fail";
}
}
And Here is the ProcessUtil.java
public class ProcessUtil {
public static void execute(String cmd) {
Process process = null;
Runtime runtime = Runtime.getRuntime();
StringBuffer successOutput = new StringBuffer();
StringBuffer errorOutput = new StringBuffer();
BufferedReader successBufferReader = null;
BufferedReader errorBufferReader = null;
String msg = null;
List<String> cmdList = new ArrayList<String>();
if (System.getProperty("os.name").indexOf("Windows") > -1) {
cmdList.add("cmd");
cmdList.add("/c");
} else {
cmdList.add("/bin/sh");
cmdList.add("-c");
}
cmdList.add(cmd);
String[] array = cmdList.toArray(new String[cmdList.size()]);
try {
process = runtime.exec(array);
successBufferReader = new BufferedReader(new InputStreamReader(process.getInputStream(), "UTF-8"));
while ((msg = successBufferReader.readLine()) != null) {
successOutput.append(msg + System.getProperty("line.separator"));
}
errorBufferReader = new BufferedReader(new InputStreamReader(process.getErrorStream(), "UTF-8"));
while ((msg = errorBufferReader.readLine()) != null) {
errorOutput.append(msg + System.getProperty("line.separator"));
}
process.waitFor();
if (process.exitValue() == 0) {
System.out.println("success!");
System.out.println(successOutput.toString());
} else {
System.out.println("fail...");
System.out.println(successOutput.toString());
}
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
try {
process.destroy();
if (successBufferReader != null)
successBufferReader.close();
if (errorBufferReader != null)
errorBufferReader.close();
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
}
The problem that I'm facing is when I open two Windows command windows and execute simultaneously it seemingly works fine. However, when I run that 'startTest' method by requesting to my server simultaneously, it pushes my CPU and RAM to nearly 100% and results seemed odd. I don't know much about multi-threading, but I guess I should execute the command via multiple windows(I think my commands were executed in the same environment and they crashed each other...). Please give me some advice to resolve this problem... Thank you in advance.

error=2, No such file or directory at java.lang.UNIXProcess.forkAndExec(Native Method)

I wrote one java program to periodically monitor the status of the devices using fping protocol. It will execute the fping command for every 5 mins. I got an above exception sometimes only. We are using this directory (/usr/local/bin/). This where fping installed. Please suggest.
public static List<String> executeProcess(String command,List<String> args,String dirPath) throws Exception {
// delegate
args.add(0,command);
args.add(1,FpingSession.FPING_RETRY);
args.add(2,FpingSession.FPING_RETRY_VALUE);
ProcessBuilder processBuilder = new ProcessBuilder(args);
if(dirPath!=null && !dirPath.isEmpty())
processBuilder.directory(new File(dirPath));
List<String> stringList;
Process process = null;
InputStream inputStream = null;
InputStreamReader inputStreamReader = null;
BufferedReader bufferedReader = null;
try {
process = processBuilder.start();
inputStream = process.getInputStream();
inputStreamReader = new InputStreamReader(
inputStream);
bufferedReader = new BufferedReader(
inputStreamReader);
stringList = new LinkedList<String>();
while (true) {
// next line
final String string = bufferedReader.readLine();
if (string == null) {
break;
}
// track
stringList.add(string);
}
} finally{
if (process != null)
process.destroy();
if (inputStream != null)
inputStream.close();
if (inputStreamReader != null)
inputStreamReader.close();
if (bufferedReader != null)
bufferedReader.close();
}
// done
return stringList;
}

Get an error trying to execute curl command from java code

I have a trouble with executing curl command from java code. I am using Runtime.getRuntime().exec(cmd) construction to execute curl. Everything worked fine until I have been stuck on receiving response about 88kb. Executing of command is freezing. My code for executing command:
public String executeSimpleBash(String[] cmd) {
StringBuilder output = new StringBuilder();
Process p;
String result;
try {
p = Runtime.getRuntime().exec(cmd);
p.waitFor(40, TimeUnit.SECONDS);
if (p.exitValue() != 0) {
result = null;
} else {
BufferedReader reader =
new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
output.append(line).append("\n");
}
result = output.toString();
}
} catch (Exception e) {
e.printStackTrace();
LOGGER.error(e.getMessage());
result = null;
}
return result;
}
My command:
String[] cmd = new String[]{
"curl",
"-H",
"text/xml",
"--insecure",
"--max-time",
"30",
"-s",
"-d",
"languageSelect=enEn&xml=" + xmlBody,
endpointUrl
};

ProcessBuilder process not running

I'm fairly new to ProcessBuilder and working with threads. In it's current state I have a J-Button which starts a scheduled executor service. The scheduled executor service is used to delegate a process to one of two process builders. The application is meant to record a user conversation. During the conversation, after x minutes it creates a wav and delegates it to an available process for transcription. The problem begins when the transcription class is called. The process is started and the application runs as expected. However, the transcription process doesn't actually do anything until I exit the parent application. Only then it will begin. Checking the task manager it shows as a process but uses 0.0% of the CPU and around 238MB of memory until I exit then the two processes jump to 30%-40% and 500-1000 MB of memory. Also, I am using the .waitFor() but am using a thread to run the .waitFor() process as from what I gather it causes the application to hang. How would I go about fixing this. Sorry I am unable to provide more details but I'm new to this. Thanks in advance!
public class TranDelegator {
Future<?> futureTranOne = null;
Future<?> futureTranTwo = null;
ExecutorService transcriberOne = Executors.newFixedThreadPool(1);
ExecutorService transcriberTwo = Executors.newFixedThreadPool(1);
final Runnable transcribeChecker = new Runnable() {
public void run() {
String currentWav = null;
File inputFile = new File("C:\\convoLists/unTranscribed.txt");
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(inputFile));
} catch (FileNotFoundException e1) {
System.out.println("reader didn't initialize");
e1.printStackTrace();
}
try {
currentWav = reader.readLine();
} catch (IOException e) {
System.out.println("currentWav string issue");
e.printStackTrace();
}
try {
reader.close();
} catch (IOException e) {
System.out.println("reader couldn't close");
e.printStackTrace();
}
if(currentWav != null){
if (futureTranOne == null || futureTranOne.isDone()) {
futureTranOne = transcriberOne.submit((transcriptorOne));
}
else if (futureTranTwo == null || futureTranTwo.isDone()) {
futureTranTwo = transcriberTwo.submit((transcriptorTwo));
}
}
}
};
final Runnable transcriptorOne = new Runnable() {
public void run() {
System.out.println("ONE");
try {
String classpath = System.getProperty("java.class.path");
String path = "C:/Program Files/Java/jre7/bin/java.exe";
ProcessBuilder processBuilder = new ProcessBuilder(path, "-cp",
classpath, Transcriber.class.getName());
Process process = processBuilder.start();
try {
process.waitFor();
} catch (InterruptedException e) {
System.out.println("process.waitFor call failed");
e.printStackTrace();
}
} catch (IOException e) {
System.out.println("Unable to call transcribeConvo");
e.printStackTrace();
}
}
};
final Runnable transcriptorTwo = new Runnable() {
public void run() {
System.out.println("TWO");
try {
String classpath = System.getProperty("java.class.path");
String path = "C:/Program Files/Java/jre7/bin/java.exe";
ProcessBuilder processBuilder = new ProcessBuilder(path, "-cp",
classpath, Transcriber.class.getName());
Process process = processBuilder.start();
try {
process.waitFor();
} catch (InterruptedException e) {
System.out.println("process.waitFor call failed");
e.printStackTrace();
}
} catch (IOException e) {
System.out.println("Unable to call transcribeConvo");
e.printStackTrace();
}
}
};
}
public class Transcriber {
public static void main(String[] args) throws IOException,
UnsupportedAudioFileException {
retreiveEmpInfo();
TextoArray saveConvo = new TextoArray();
ArrayList<String> entireConvo = new ArrayList();
URL audioURL;
String currentWav = wavFinder();
ConfigReader configuration = new ConfigReader();
ArrayList<String> serverInfo = configuration
.readFromDoc("serverconfig");
while (currentWav != null) {
audioURL = new URL("file:///" + currentWav);
URL configURL = Transcriber.class.getResource("config.xml");
ConfigurationManager cm = new ConfigurationManager(configURL);
Recognizer recognizer = (Recognizer) cm.lookup("recognizer");
recognizer.allocate(); // allocate the resource necessary for the
// recognizer
System.out.println(configURL);
// configure the audio input for the recognizer
AudioFileDataSource dataSource = (AudioFileDataSource) cm
.lookup("audioFileDataSource");
dataSource.setAudioFile(audioURL, null);
// Loop until last utterance in the audio file has been decoded, in
// which case the recognizer will return null.
Result result;
while ((result = recognizer.recognize()) != null) {
String resultText = result.getBestResultNoFiller();
// System.out.println(result.toString());
Collections.addAll(entireConvo, resultText.split(" "));
}
new File(currentWav).delete();
saveConvo.Indexbuilder(serverInfo, entireConvo);
entireConvo.clear();
currentWav = wavFinder();
}
System.exit(0);
}
private static String wavFinder() throws IOException {
String currentWav = null;
int x = 1;
File inputFile = new File("C:\\convoLists/unTranscribed.txt");
File tempFile = new File("C:\\convoLists/unTranscribedtemp.txt");
BufferedReader reader = new BufferedReader(new FileReader(inputFile));
BufferedWriter writer = new BufferedWriter(new FileWriter(tempFile));
String currentLine = null;
String newLine = System.getProperty("line.separator");
while ((currentLine = reader.readLine()) != null) {
if (x == 1) {
currentWav = currentLine;
} else {
writer.write(currentLine);
writer.write(newLine);
}
x = 2;
}
reader.close();
writer.flush();
writer.close();
inputFile.delete();
// boolean successful =
tempFile.renameTo(inputFile);
// System.out.println("Success: " + successful);
// System.out.println("currentWav = " + currentWav);
return currentWav;
}
private static void retreiveEmpInfo() throws IOException {
File tempFile = new File("C:\\convoLists/tmp.txt");
BufferedReader reader = new BufferedReader(new FileReader(tempFile));
CurrentEmployeeInfo.setName(reader.readLine());
CurrentEmployeeInfo.setUserEmail(reader.readLine());
CurrentEmployeeInfo.setManagerEmail(reader.readLine());
reader.close();
}
}

This problem may be related to sub-process's input stream buffers.
You should clear the sub-process's input stream buffers.
These stream buffers got increased within the parent process's memory with time and at some moment your sub-process will stop responding.
There are few options to make sub-process work normally
Read continuously from sub-process's input streams
Redirect sub-process's input streams
Close sub-process's input streams
Closing sub-process's input streams
ProcessBuilder processBuilder = new ProcessBuilder(command);
Process process = processBuilder.start();
InputStream inStream = process.getInputStream();
InputStream errStream = process.getErrorStream();
try {
inStream.close();
errStream.close();
} catch (IOException e1) {
}
process.waitFor();
Reading sub-process's input streams
ProcessBuilder processBuilder = new ProcessBuilder(command);
Process process = processBuilder.start();
InputStreamReader tempReader = new InputStreamReader(new BufferedInputStream(p.getInputStream()));
final BufferedReader reader = new BufferedReader(tempReader);
InputStreamReader tempErrReader = new InputStreamReader(new BufferedInputStream(p.getErrorStream()));
final BufferedReader errReader = new BufferedReader(tempErrReader);
try {
while ((line = reader.readLine()) != null) {
}
} catch (IOException e) {
}
try {
while ((line = errReader.readLine()) != null) {
}
} catch (IOException e) {
}
process.waitFor();
Redirecting sub-process's input streams
ProcessBuilder processBuilder = new ProcessBuilder(command);
processBuilder.redirectInput();
processBuilder.redirectError();
Process process = processBuilder.start();
process.waitFor();

(from comments)
Looks like process hang is due to out/error streams becoming full. You need to consume these streams; possibly via a thread.
Java7 provides another way to redirect output.
Related : http://alvinalexander.com/java/java-exec-processbuilder-process-3

android get stderr of command

How can i get the stderr of a python binary? It is showing the output of the python script but it is not showing the errors that might be in the script, what java method should i be using? or is there a python command line argument that i can use to display the errors?
private String exec(String command)
{
try
{
String s = getApplicationInfo().dataDir;
File file2 = new File(s+"/py");
file2.setExecutable(true);
File externalStorage = Environment.getExternalStorageDirectory();
String strUri = externalStorage.getAbsolutePath();
PrintWriter out = new PrintWriter(strUri+"/temp.py");
out.write(command);
out.close();
saveRawToFile();
Process process = Runtime.getRuntime().exec(s+"/py "+strUri+"/temp.py");
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
int read;
char[] buffer = new char[4096];
StringBuffer output = new StringBuffer();
while ((read = reader.read(buffer)) > 0)
{
output.append(buffer, 0, read);
}
reader.close(); process.waitFor();
return output.toString();
}
catch (IOException e)
{ throw new RuntimeException(e); }
catch (InterruptedException e)
{ throw new RuntimeException(e); }
}
private void output(final String str)
{
Runnable proc = new Runnable() {
public void run()
{
outputView.setText(str);
outputView.setTextIsSelectable(true);
}
};
handler.post(proc);
}

Use Process#getErrorStream(), just like you used getOutputStream().