Develop Reference

WMIC Java command not working after exe installation

A very simple code running in the debugging mode perfectly but not working after installation of exe, giving no response/result in return. even no errors to trace.
After building a .exe and installing on my PC its happening, very strange.
tried process builder but the same thing, anyway to check/trace it. maybe paths ?
StringBuilder b = new StringBuilder();
Process p = Runtime.getRuntime().exec("wmic diskdrive get signature");
BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
b.append(line);
}
Please note: CMD /c before commands also return an empty response in actual env.

An internal windows command with arguments, like "wmic diskdrive ..."
can be executed easily by wrapping it up inside a cmd window.
Here is the working code snippet for running the wmic command encapsulated in a cmd window:
import java.io.*;
public class Wmic {
public static void main(String[] args) {
StringBuilder b = new StringBuilder();
try {
// Initialize a process object to run
// wmic command and its parameters
// inside a cmd window
Process process = Runtime.getRuntime()
.exec("cmd /c C:\\Windows\\System32\\wbem\\WMIC.exe diskdrive get signature");
BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
b.append(line);
}
} catch (Exception ex) {
b.append(ex.toString());
}
System.out.println("Output: \n" + b.toString());
}
}
Output:
>javac Wmic.java
>java Wmic
Output:
Signature
More information:
https://mkyong.com/java/how-to-execute-shell-command-from-java/

The ProcessBuilder constructor takes a list of strings. When using ProcessBuilder to run a command, I separate all the words in the command into separate strings.
I read the output of the process in a separate thread. And I always wait for the command, that I launched via ProcessBuilder, to terminate.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.StringWriter;
public class PrcBldTs {
public static void main(String[] args) {
ProcessBuilder pb = new ProcessBuilder("wmic","diskdrive","get","signature");
try {
Process proc = pb.start();
StreamGobbler error = new StreamGobbler(proc.getErrorStream());
StreamGobbler output = new StreamGobbler(proc.getInputStream());
Thread stdout = new Thread(output);
Thread stderr = new Thread(error);
stdout.start();
stderr.start();
int result = proc.waitFor();
stdout.join();
stderr.join();
System.out.println("Exit status = " + result);
if (result != 0) {
System.out.println(error.getContents());
}
else {
System.out.println(output.getContents());
}
}
catch (IOException | InterruptedException x) {
x.printStackTrace();
}
}
}
class StreamGobbler implements Runnable {
private BufferedReader reader;
private StringWriter sw;
public StreamGobbler(InputStream is) {
InputStreamReader isr = new InputStreamReader(is);
reader = new BufferedReader(isr);
sw = new StringWriter();
}
public String getContents() {
return sw.toString();
}
public void run() {
try {
String line = reader.readLine();
while (line != null) {
sw.append(line);
sw.append(System.lineSeparator());
line = reader.readLine();
}
}
catch (IOException xIo) {
throw new RuntimeException(xIo);
}
}
}
Running the above code gave me the following output.
Exit status = 0
Signature
1145609371

java ProcessBuilder run shell script is hanging

I'm trying to run shell script by using ProcessBuilder. The script works but it can't run after the java code. And error stream doesn't output message. I'm running it on centOS 6.9 computer. Please find below my code.
public static ArrayList<String> runCommand(ArrayList<String> command)throws IOException {
ProcessBuilder processBuilder = new ProcessBuilder();
processBuilder.command(command);
Process process = processBuilder.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
BufferedReader errorReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
ArrayList<String> commandOutput = new ArrayList<>();
String str;
while((str = reader.readLine()) != null) {
commandOutput.add(str);
}
StringBuilder errorBuilder = new StringBuilder();
while((str = errorReader.readLine()) != null) {
errorBuilder.append(str);
}
String errorMessage = errorBuilder.toString();
if(!errorMessage.equals("")) {
String message = LOG_TAG + ",[runCommand] error:" + errorMessage;
System.out.println(message);
}
reader.close();
errorReader.close();
process.destroy();
return commandOutput;
}

In your case, you are reading something from the output stream of the process, till you consume everything. Then, you try to read error stream.
If the process writes some considerable number of characters on the error stream, the other process will block till they are consumed. To consume both error stream and output stream at the same time, you need to use threads.
You may follow the StreamGobbler technique. You may get some details from that page: https://www.javaworld.com/article/2071275/when-runtime-exec---won-t.html?page=2
This is some code influenced from the page:
public class StreamGobbler extends Thread {
private static final String EOL = System.lineSeparator();
private final InputStream inputStream;
private final StringBuilder output = new StringBuilder();
public StreamGobbler(InputStream inputStream) {
this.inputStream = inputStream;
}
public void run() {
try (InputStreamReader inputStreamReader = new InputStreamReader(inputStream);
BufferedReader reader = new BufferedReader(inputStreamReader);
) {
String line;
while ((line = reader.readLine()) != null) {
output.append(line);
output.append(EOL);
}
} catch (IOException ioe) {
ioe.printStackTrace();
}
}
public String getOutput() {
return output.toString();
}
}
In your code, you use StreamGobbler like this:
StreamGobbler outputGobbler = new StreamGobbler(process.getInputStream());
StreamGobbler errorGobbler = new StreamGobbler(process.getErrorStream());
process.waitFor();
String commandOutput = outputGobbler.getOutput();
String errorMessage = errorGobbler.getOutput();
process.destroy();

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();
}
}
}
}

A jar started with Runtime.getRuntime().exec() runs longer than from command line

I have following problem:
I have simple .jar program who writes in a text console..
If I start using cmd (java -jar myProgram.jar) the program runs 1 second.
But I want to start program from another program using the JButton:
startMyProgram.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
// Run a java app in a separate system process
Process proc = Runtime.getRuntime().exec("java -jar myProgram.jar");
// Then retreive the process output
InputStream in = proc.getInputStream();
InputStream err = proc.getErrorStream();
System.out.println(convertStreamToString(in));
}
});
If i use a second way(JButton way), the program runs 10 second.
Why? Why run so long?
If i start him go through another thread , it takes too long to 10s.

Based on StreamGobbler from When Runtime Exec Won't without extending Thread directly.
public class StreamGobbler implements Runnable {
private InputStream in;
public StreamGobbler(InputStream in) {
this.in = in;
}
#Override
public void run() {
InputStreamReader isr = new InputStreamReader(in);
BufferedReader br = new BufferedReader(isr);
try {
String line = null;
while ((line = br.readLine()) != null) {
// could log it here
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
Use it to sink all the output from the streams after the exec()
Process proc = Runtime.getRuntime().exec("java -jar myProgram.jar");
...
new Thread(new StreamGobbler(in)).start();
new Thread(new StreamGobbler(err)).start();;