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running ffmpeg command in java Process hangs in waitFor()

I'm running ffmpeg command to generate video for given images (img001.jpg, img002.jpg ...) it's creating slide.mp4, but it waits infinitely:
public class Ffmpeg {
public static void main(String[] args) throws IOException, InterruptedException {
String path = "E:\\pics\\Santhosh\\FadeOut\\testing";
String cmd = "ffmpeg -r 1/5 -i img%03d.jpg -c:v libx264 -r 30 -y -pix_fmt yuv420p slide.mp4";
runScript (path, cmd);
}
private static boolean runScript(String path, String cmd) throws IOException, InterruptedException {
List<String> commands = new ArrayList<String>();
commands.add("cmd");
commands.add("/c");
commands.add(cmd);
ProcessBuilder pb = new ProcessBuilder(commands);
pb.directory(new File(path));
pb.redirectErrorStream(true);
Process process = pb.start();
flushInputStreamReader(process);
int exitCode = process.waitFor();
return exitCode == 0;
}
}
private static void flushInputStreamReader (Process process) throws IOException, InterruptedException {
BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line=null;
StringBuilder s = new StringBuilder();
while((line=input.readLine()) != null) {
s.append(line);
}
}
Any suggestions?
After writing the function flushInputStreamReader, its working

Aside from reading the ErrorStream, there's a better way to handle this.
Add -loglevel quiet to the command, so that the ErrorStream won't overflow and blocking the process at the first place.

Here the working code for the live project:
public void executeHLS() throws IOException, InterruptedException {
String original_video_file = "C:\\xampp\\htdocs\\hls\\test.mp4";
String conversion = "cmd.exe /c F:\\java\\ffmpeg\\ffmpeg\\bin\\ffmpeg -i "+original_video_file+" -hls_time 10 -hls_playlist_type vod -hls_segment_filename \"C:\\xampp\\htdocs\\hls\\video_segments_%0d.ts\" C:\\xampp\\htdocs\\hls\\hls_master_for_test.m3u8";
//String conversion = "cmd.exe /c "+"dir";
String[] cmds={conversion};
for(int i=0;i<cmds.length;i++) {
try {
System.out.println(cmds[i]);
if(runScript(conversion)) {
System.out.println("Operation Successfull!!!!");
}else {
System.out.println("Operation Failed ####");
}
} catch (IOException e) {
e.printStackTrace();
}
//System.exit(0);
}
}
private static boolean runScript(String cmd) throws IOException, InterruptedException {
ArrayList<String> commands = new ArrayList<String>();
commands.add("cmd");
commands.add("/c");
commands.add(cmd);
ProcessBuilder pb = new ProcessBuilder(commands);
//pb.directory(new File(path));
pb.redirectErrorStream(true);
Process process = pb.start();
flushInputStreamReader(process);
int exitCode = process.waitFor();
return exitCode == 0;
}
private static void flushInputStreamReader (Process process) throws IOException, InterruptedException {
BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line=null;
StringBuilder s = new StringBuilder();
while((line=input.readLine()) != null) {
s.append(line);
}
}

Running External Program in Eclipse

I am able to print the output of an external program in Eclipse via the code below (found online, not mine). I would like to be able to pass a command to the program and THEN print the output of the program but I don't know how to pass commands to the program. Any suggestions would be appreciated, thanks!
Code:
String line;
Process p = Runtime.getRuntime().exec("Z:/LPCXpresso/test10/Debug/arm-none-eabi-readelf.exe");
BufferedReader bri = new BufferedReader(new InputStreamReader(p.getInputStream()));
BufferedReader bre = new BufferedReader(new InputStreamReader(p.getErrorStream()));
while ((line = bri.readLine()) != null) {
System.out.println(line);
}
bri.close();
while ((line = bre.readLine()) != null) {
System.out.println(line);
}
bre.close();
p.waitFor();

First I would recommend using ProcessBuilder instead of Runtime.getRuntime().exec(...)
Second to be able to interact with the different streams of the process started you need to do it concurrently, i.e. for each stream create an own Thread where you interact with it.
Here is a sample code wihch illustrates interaction with the command line prompt in windows cmd.exe
public static void main(String... args) throws Exception {
ProcessBuilder pb = new ProcessBuilder("cmd.exe");
Process proc = pb.start();
// handle each of proc's streams in a separate thread
ExecutorService handlerThreadPool = Executors.newFixedThreadPool(3);
handlerThreadPool.submit(new Runnable() {
#Override
public void run() {
// we want to write to the stdin of the process
BufferedWriter stdin = new BufferedWriter(
new OutputStreamWriter(proc.getOutputStream()));
// read from our own stdin so we can write it to proc's stdin
BufferedReader myStdin =
new BufferedReader(new InputStreamReader(System.in));
String line = null;
try {
do {
line = myStdin.readLine();
stdin.write(String.format("%s%n", line));
stdin.flush();
} while(! "exit".equalsIgnoreCase(line));
} catch(IOException e) {
e.printStackTrace();
}
}
});
handlerThreadPool.submit(new Runnable() {
#Override
public void run() {
// we want to read the stdout of the process
BufferedReader stdout = new BufferedReader(
new InputStreamReader(proc.getInputStream()));
String line;
try {
while(null != (line = stdout.readLine())) {
System.out.printf("[stdout] %s%n", line);
}
} catch(IOException e) {
e.printStackTrace();
}
}
});
handlerThreadPool.submit(new Runnable() {
#Override
public void run() {
// we want to read the stderr of the process
BufferedReader stderr = new BufferedReader(
new InputStreamReader(proc.getErrorStream()));
String line;
try {
while(null != (line = stderr.readLine())) {
System.err.printf("[stderr] %s%n", line);
}
} catch(IOException e) {
e.printStackTrace();
}
}
});
// wait for the process to terminate
int exitCode = proc.waitFor();
System.out.printf("Process terminated with exit code %d%n", exitCode);
handlerThreadPool.shutdown();
}
You could make it simple and redirect of the process stderr to stdout using ProcessBuilder#redirectErrorStream(true) before starting the process and then have only 2 threads, one for input and one for output

Run Scala REPL via Java ProcessBuilder

For research reasons I want to be able to call the Scala REPL in my Java code. To do so I use Java's ProcessBuilder and call the command scala. Although the code nicely returns the welcome message of the scala REPL, the statements that I sent to it do not return any output or errors.
Note that my use of processbuilder is correct, I tested it on other commands and it works. It is specifically Scala that is not giving me any output or errors.
Why isn't Scala giving me any output? Is there a way to make it work?
Here is the short compilable version of my code:
public class CommandEvaluator {
public static void main(String args[]) throws IOException
{
ProcessBuilder pb = new ProcessBuilder("scala.bat");
Process proc = pb.start();
StreamGobbler errorGobbler = new StreamGobbler(proc.getErrorStream(), "ERR");
StreamGobbler outputGobbler = new StreamGobbler(proc.getInputStream(), "OUT");
// kick them off
errorGobbler.start();
outputGobbler.start();
OutputStream outStream = proc.getOutputStream();
PrintWriter pWriter = new PrintWriter(outStream);
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
while (true) { // REPL
System.out.print("> ");
String stat = br.readLine();
pWriter.println(stat);
pWriter.flush();
}
}
private static class StreamGobbler extends Thread
{
private String type;
private BufferedReader br;
StreamGobbler(InputStream is, String type)
{
this.type = type;
InputStreamReader isr = new InputStreamReader(is);
br = new BufferedReader(isr);
}
#Override
public void run()
{
try
{
String line = null;
while ((line = br.readLine()) != null)
System.out.println(type + ">" + line);
}
catch (IOException ioe)
{
ioe.printStackTrace();
}
}
}
}

how to run a java executable jar in another java program

I know this question has been asked before but those answers didn't provide me an answer.
I want to execute a exec jar file in my java program and get the output from executing jar into a string. Here below are the codes I have used so far without success.
cmdlink = "java -jar iwtest-mac.jar"+" "+cmd;
System.out.println(cmdlink);
Process process = Runtime.getRuntime().exec(cmdlink);
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while ((reader.readLine()) != null) {
st = reader.readLine();
}
process.waitFor();
and another code I have tried is as follows:
String cmdlink = "iwtest-mac.jar "+cmd;
ProcessBuilder pb = new ProcessBuilder("java", "-jar", cmdlink); //cmd here is a string that contains inline arguments for jar.
pb.redirectErrorStream(true);
pb.directory(new File("C:\\Users\\Dharma"));
System.out.println("Directory: " + pb.directory().getAbsolutePath());
Process p = pb.start();
InputStream is = p.getInputStream();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
for (String line = br.readLine(); line != null; line = br.readLine()) {
System.out.println( line );
p.waitFor();
Both of the above are not working for me. Any suggestions are appreciated.

This works For Me..
public class JarRunner {
public static void main(String[] args) {
ProcessBuilder pb = new ProcessBuilder("java", "-jar", "C:\\JCcc.jar");
pb.directory(new File("C:\\"));
try {
Process p = pb.start();
LogStreamReader lsr = new LogStreamReader(p.getInputStream());
Thread thread = new Thread(lsr, "LogStreamReader");
thread.start();
} catch (IOException e) {
e.printStackTrace();
}
}
}
class LogStreamReader implements Runnable {
private BufferedReader reader;
public LogStreamReader(InputStream is) {
this.reader = new BufferedReader(new InputStreamReader(is));
}
public void run() {
try {
String line = reader.readLine();
while (line != null) {
System.out.println(line);
line = reader.readLine();
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
This is what the Docs says-
ProcessBuilder pb = new ProcessBuilder("myCommand", "myArg1", "myArg2");
You can pass any number of arguments in constructor.
Read more about process builder here.

Java program hangs when trying to invoke powershell script

I'm building a GUI with NetBeans, and one of the buttons in the GUI requires the use of a powershell script. I'm trying to get the script's output and put it into a JTextArea within the GUI. Here is what I have so far. I did a bit of debugging, and it seems to hang inside the while loop, but I'm confused as to why it's doing so.
private void runButtonActionPerformed(java.awt.event.ActionEvent evt) {
try {
Runtime runtime = Runtime.getRuntime();
Process proc = runtime.exec("cmd powershell C:/hello1.ps1");
InputStream is = proc.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader reader = new BufferedReader(isr);
String line;
while ((line = reader.readLine()) != null) {
outputTextArea.setText(line);
}
reader.close();
proc.getOutputStream().close();
} catch (IOException ex) {
Logger.getLogger(BatchFrame.class.getName()).log(Level.SEVERE, null, ex);
}
}
And here is a simple powershell script I'm trying to get it to work with.
#Filename: hello1.ps1
Write-Host "Hello World!"
#End of Script
I did some researched, and I noticed that it was hanging for other people to, but only because they forgot to close the processes output stream.

I was having the same issue. I moved the proc.getOutputStream().close() before the while loop and everything worked

private void runButtonActionPerformed(java.awt.event.ActionEvent evt) {
String allOutput = "";
try {
Runtime runtime = Runtime.getRuntime();
Process proc = runtime.exec("cmd /c powershell C:/hello1.ps1");
BufferedReader errorReader = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
BufferedReader outReader = new BufferedReader(new InputStreamReader(proc.getInputStream()));
String line;
while ((line = errorReader.readLine()) != null) {
allOutput += "\n" + line;
}
while ((line = outReader.readLine()) != null) {
allOutput += "\n" + line;
}
int retVal = proc.waitFor();
} catch (IOException ex) {
Logger.getLogger(BatchFrame.class.getName()).log(Level.SEVERE, null, ex);
}
outputTextArea.setText(allOutput);
}
Form the command line properly with CMD.EXE /c
Check the ErrorStream
Use Process.waitFor() read the java-docs for the Process class.
No need to close the OutputStream since you never use it and the program shouldn't expect user input (java switching the names of input and output is annoying)
NOTE the code above isn't tested, so there may be syntax errors etc etc.

Here is my tested code, note the choice to "hack" or close STDIN when done.
package test;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class Test
{
private static boolean hack=false;
public static void main(String[] args) throws IOException
{
Runtime rt = Runtime.getRuntime();
String cmd[];
if (hack)
cmd=new String[]{"cmd","/c","C:\\WINDOWS\\system32\\WindowsPowerShell\\v1.0\\powershell.exe","-File","c:\\cygwin\\home\\jpyeron\\test.ps1", "<NUL"};
else
cmd=new String[]{"C:\\WINDOWS\\system32\\WindowsPowerShell\\v1.0\\powershell.exe","-File","c:\\cygwin\\home\\jpyeron\\test.ps1"};
final Process p = rt.exec(cmd);
Thread stdout = new Thread()
{
public void run()
{
InputStream out = p.getInputStream();
BufferedReader in = new BufferedReader(new InputStreamReader(out));
String line = null;
try
{
while ((line = in.readLine()) != null)
{
System.out.println(line);
}
}
catch (IOException e)
{
e.printStackTrace();
}
};
};
stdout.start();
Thread stderr = new Thread()
{
public void run()
{
InputStream err = p.getInputStream();
BufferedReader in = new BufferedReader(new InputStreamReader(err));
String line = null;
try
{
while ((line = in.readLine()) != null)
{
System.out.println(line);
}
}
catch (IOException e)
{
e.printStackTrace();
}
};
};
stderr.start();
if (hack)
;
else
p.getOutputStream().close();
}
}

This helped me: Do not read the InputStream if there are no errors.
e.g.
private void takeAction () throws IOException, InterruptedException
{
String action = getAction (); // A powershell-Command
Process p = Runtime.getRuntime ().exec ( action );
InputStream is = p.getErrorStream ();
if ( 0 < is.available () )
{
BufferedReader br = new BufferedReader (
new InputStreamReader ( is ) );
String err = br.readLine ();
while ( null != err )
{
System.out.println ( "takeAction() " + err );
err = br.readLine ();
}
p.getOutputStream ().close ();
}
}