Develop Reference

how to in java start and interact with the console application

I have a console application written in c, it runs in the console and has its own pseudo-console. Through it, I configure this application and run it. All OK.
Now I am trying to run this application inside a Java application, and I have problems.
As an example, I use sh
ProcessBuilder builder = new ProcessBuilder("sh");
builder.redirectErrorStream(true);
Process process = builder.start();
try (BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(process.getOutputStream()))) {
bw.write("echo lol");
while (true) {
// System.out.println(process.isAlive());
if (br.ready()) {
System.out.println(br.readLine());
}
}
} catch (Exception ex) {
ex.printStackTrace();
}
The main idea is to run the application in the console and send several commands to it.

So, after a few experiments, I get the answer.
ProcessBuilder builder = new ProcessBuilder("sh");
Process process = builder.start();
BufferedReader br = new BufferedReader(new InputStreamReader(process.getInputStream()));
new Thread(new Runnable() {
public void run() {
Scanner scan = new Scanner(br);
while (true) {
try {
if (!br.ready()) break;
System.out.println(br.readLine());
} catch (IOException e) {
e.printStackTrace();
}
}
}
}).start();
PrintWriter bw = new PrintWriter(process.getOutputStream());
bw.println("echo Hello World");
bw.println("echo lol");
bw.flush();
bw.close();

Execute powershell script in Java JSFrame

I have developed a demo app in JSFrame which should execute powershell script in my folder.
I am trying following code.
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try
{
Runtime runtime = Runtime.getRuntime();
Process proc = runtime.exec("powershell C:\\helloworld.ps1");
InputStream is = proc.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader reader = new BufferedReader(isr);
String line;
while ((line = reader.readLine()) != null)
{
System.out.println(line);
}
reader.close();
proc.getOutputStream().close();
}
catch(Exception ex)
{
}
}
And in helloworld.ps1, I am having following command :
$strString = "Hello World 123"
write-host $strString
But I am not getting any output.

Executing 'adb logcat' command using Runtime class

I was trying to get the logcat content into a JTextPane. I used following code hoping it will return the content as String but it freeze and also, doesn't produce an error.
Process exec = null;
try {
exec = Runtime.getRuntime().exec("adb logcat -d");
InputStream errorStream = exec.getErrorStream();
BufferedReader ebr = new BufferedReader(new InputStreamReader(errorStream));
String errorLine;
while ((errorLine = ebr.readLine()) != null) {
System.out.println("[ERROR] :- " + errorLine);
}
if (exec.waitFor() == 0) {
InputStream infoStream = exec.getInputStream();
InputStreamReader isr = new InputStreamReader(infoStream);
BufferedReader ibr = new BufferedReader(isr);
String infoLine;
while ((infoLine = ibr.readLine()) != null) {
System.out.println("[INFO] :- " + infoLine);
}
}
} catch (IOException | InterruptedException ex) {
ex.printStackTrace();
} finally {
if (exec != null) {
exec.destroy();
}
}
I referred to some tutorials but, they were not filling my problem. Is this wrong? Are there any other methods to get the logcat content as a String programmatically? Sorry if this is a dumb question.

The issue you're seeing is that you're trying to process command streams and wait for the executing process, all in the same thread. It's blocking because the process reading the streams is waiting on the process and you're losing the stream input.
What you'll want to do is implement the function that reads/processes the command output (input stream) in another thread and kick off that thread when you start the process.
Second, you'll probably want to use ProcessBuilder rather than Runtime.exec.
Something like this can be adapted to do what you want:
public class Test {
public static void main(String[] args) throws Exception {
String startDir = System.getProperty("user.dir"); // start in current dir (change if needed)
ProcessBuilder pb = new ProcessBuilder("adb","logcat","-d");
pb.directory(new File(startDir)); // start directory
pb.redirectErrorStream(true); // redirect the error stream to stdout
Process p = pb.start(); // start the process
// start a new thread to handle the stream input
new Thread(new ProcessTestRunnable(p)).start();
p.waitFor(); // wait if needed
}
// mimics stream gobbler, but allows user to process the result
static class ProcessTestRunnable implements Runnable {
Process p;
BufferedReader br;
ProcessTestRunnable(Process p) {
this.p = p;
}
public void run() {
try {
InputStreamReader isr = new InputStreamReader(p.getInputStream());
br = new BufferedReader(isr);
String line = null;
while ((line = br.readLine()) != null)
{
// do something with the output here...
}
}
catch (IOException ex) {
ex.printStackTrace();
}
}
}
}

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

Cannot run 'cmd' command with parameters 'sc sdshow w32time'

I am trying to run an external process in Java and I have no idea why my code isn't working. It works for any other 'cmd' command (for example /c dir). If I replace cmd sc sdshow w32time with cmd /c dir it works.
Here is my code:
public class services2 {
public static void main(String args[]) {
try {
Process p = Runtime.getRuntime().exec("cmd sc sdshow w32time");
p.waitFor();
BufferedReader reader = new BufferedReader(new InputStreamReader(
p.getInputStream()));
String line = reader.readLine();
while (line != null) {
System.out.println(line);
line = reader.readLine();
}
} catch (IOException e1) {
} catch (InterruptedException e2) {
}
System.out.println("Done");
}
}
Any ideas?

Your problem seems to be that sc is not an argument for cmd.
What you need is:
sc sdshow w32time