Develop Reference

Java Process Builder - Cannot run a simple program

I have a program called darknet. It's a C-program made from Darknet.
I want to run the darknet program in a folder Darknet that looks like this:
I'm going to run darknet with Java Process Builder, but I get no responce from it when I run this code:
// Arguments
String darknetNamePath = darknet.getValue().getFilePath().replace("Darknet/", "./");
String configurationFlag = configuration.getValue().getFilePath().replace("Darknet/", "");
String weightsFlag = weights.getValue().getFilePath().replace("Darknet/", "");
String imageFlag = "data/cameraSnap.png";
String thresholdFlag = "-thresh " + thresholds.getValue();
// Process builder
ProcessBuilder processBuilder = new ProcessBuilder();
processBuilder.directory(new File("Darknet")); // We need to stand inside the folder "Darknet"
String commandString = "detect " + configurationFlag + " " + weightsFlag + " " + imageFlag + " " + thresholdFlag;
System.out.println("darknetNamePath = " + darknetNamePath);
System.out.println("commandString = " + commandString);
processBuilder.command(darknetNamePath, commandString);
Process process = processBuilder.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
int exitCode = process.waitFor();
System.out.println("\nExited with error code : " + exitCode);
Here is my output. Why doesn't it work for me?
darknetNamePath = ./darknet
commandString = detect cfg/yolov2-tiny.cfg weights/yolov2-tiny.weights data/cameraSnap.png -thresh 0.8
Exited with error code : 0
But when I call darknet file via terminal, then it works.
./darknet detect cfg/yolov2-tiny.cfg weights/yolov2-tiny.weights data/cameraSnap.png -thresh 0.6
UPDATE 2:
Here is my update.
// Arguments
String darknetNamePath = darknet.getValue().getFile().getAbsolutePath();
String configurationFlag = configuration.getValue().getFilePath().replace("Darknet/", "");
String weightsFlag = weights.getValue().getFilePath().replace("Darknet/", "");
String imageFlag = "data/cameraSnap.png";
String thresholdFlag = "-thresh " + thresholds.getValue();
// Process builder
ProcessBuilder processBuilder = new ProcessBuilder();
processBuilder.command(darknetNamePath, "detect", configurationFlag, weightsFlag, imageFlag, thresholdFlag);
Process process = processBuilder.start();
if (process.getInputStream().read() == -1) {
System.out.println(darknetNamePath);
System.out.println("detect");
System.out.println(configurationFlag);
System.out.println(weightsFlag);
System.out.println(imageFlag);
System.out.println(thresholdFlag);
System.out.printf("ERROR!");
}
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
int exitCode = process.waitFor();
System.out.println("\nExited with error code : " + exitCode);
Output:
/home/dell/Dokument/GitHub/Vaadin-DL4J-YOLO-Camera-Mail-Reporter/Vaadin-DL4J-YOLO-Camera-Mail-Reporter/Darknet/darknet
detect
cfg/yolov2-tiny.cfg
weights/yolov2-tiny.weights
data/cameraSnap.png
-thresh 0.3
ERROR!
Exited with error code : 0
UPDATE 3:
This works:
// Arguments
String darkPath = darknet.getValue().getFilePath().replace("Darknet/", "./"); // We need to call ./darknet, not absolute path
String configurationFlag = configuration.getValue().getFilePath().replace("Darknet/", "");
String weightsFlag = weights.getValue().getFilePath().replace("Darknet/", "");
String imageFlag = "data/camera.png";
String thresValue = String.valueOf(thresholds.getValue());
// Process builder
ProcessBuilder processBuilder = new ProcessBuilder();
processBuilder.directory(new File("Darknet")); // Important
processBuilder.command(darkPath, "detect", configurationFlag, weightsFlag, imageFlag, "-thresh", thresValue);
processBuilder.redirectErrorStream(true); // Important
Process process = processBuilder.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
int exitCode = process.waitFor();
System.out.println("\nExited with error code : " + exitCode);

Your command must break all arguments into separate pieces - including thresholdFlag. It is a good idea to check if the executable exists. If it does not you should check where it is located or fix your Path variable to ensure that it can be located:
File darkpath = new File(darknetNamePath);
String [] cmd = new String[] { darkpath.getAbsolutePath(), "detect", configurationFlag, weightsFlag, imageFlag, "-thresh", String.valueOf(thresholds.getValue()) };
System.out.println("Path: "+darkpath+ " exists="+darkpath.exists());
System.out.println("exec "+Arrays.toString(cmd));
processBuilder.command(cmd);
It is also worth handling STDERR, the easiest way is to redirect STDERR=>STDOUT before calling processBuilder.start()
processBuilder.redirectErrorStream(true);
If you want Java to launch the executable without prefixing the absolute path it needs to be in one of these directories:
System.out.println("PATH COMPONENTS FOR JAVA LAUNCH:");
Arrays.asList(System.getenv("PATH").split(File.pathSeparator)).forEach(System.out::println);

You are using ProcessBuilder the wrong way. The command method takes a executable and arguments as separate strings, not a path and then another string with the actual command and all its arguments. There is no shell involved to do word splitting on the command, so you pass all your distinct arguments as one argument.
I don't have darknet, so here's a simple command using the Unix echo command:
import java.io.*;
public class ProcessBuilderTest {
public static void main(String[] args) throws Exception {
ProcessBuilder processBuilder = new ProcessBuilder();
String[] command = {"/bin/echo", "hello", "world"};
processBuilder.command(command);
Process process = processBuilder.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
int exitCode = process.waitFor();
System.out.println("Exited with error code : " + exitCode);
}
}
When I run this, I get:
robert#saaz:~$ java ProcessBuilderTest.java
hello world
Exited with error code : 0
It's not clear to my why your command doesn't produce an error. If I give a bad command (e.g., a trailing space behind "echo"), I get an exception:
Exception in thread "main" java.io.IOException: Cannot run program "/bin/echo ": error=2, No such file or directory
This may be OS specific. Or maybe you have some other darknet executable that gets picked up.

Run bat file from different disk with java

Im trying to run a bat from C:/abc/def/coolBat.bat but my java workspace is in D:/
I've tried with :
String cmd = "cmd /c /start C:/abc/def/coolBat.bat";
Runtime.getRuntime().exec(cmd);
But didn't work, so I tried this
String[] command = { "cmd.exe", "/C", "C:/abc/def/coolBat.bat" };
Runtime.getRuntime().exec(cmd);
didnt work either. Tried this too
Executor exec = new DefaultExecutor();
exec.setWorkingDirectory(new File("C:/abc/def"));
CommandLine cl = new CommandLine("coolBat.bat");
int exitvalue = exec.execute(cl);
Says it cant find the file.
Tried something like this too:
Runtime.getRuntime().exec("cmd cd /d C:/abc/def/ && coolBat.bat");
And nothing. The weird thing is that this command:
cd /d C:/abc/def/ && coolBat.bat
Works when i do it in cmd. Its worth saying that the bat file copies some files to another directory, all inside C:/
EDITED N°1
CD C:\abc\def\MN
copy almn + ctmn + bamn C:\abc\def\mn_sf.txt
CD C:\abc\def\ME
copy alme + ctme + bame C:\abc\def\me_sf.txt
CD C:\abc\def\
if exist MN.txt del MN.txt
if exist ME.txt del ME.txt
if exist JUZ.txt del JUZ.txt
if exist FUNC.txt del FUNC.txt
if exist AHO.txt del AHO.txt
CD C:\

Allow MS Windows to use the associated application to run your batch file (or any other application):
Required Imports:
import java.awt.Desktop;
Here is code you can try:
String filePath = "C:/abc/def/coolBat.bat";
if (Desktop.isDesktopSupported()) {
try {
File myFile = new File(filePath);
Desktop.getDesktop().open(myFile);
}
catch (IOException | IllegalArgumentException ex) {
System.err.println("Either there is no application found "
+ "which is associatd with\nthe file you want to work with or the "
+ "file doesn't exist!\n\n" + filePath);
}
}

Well I finally got it to work, just had to change my workspace to C:/
Apparently the problem was that it couldn't change from D:/ to C:/ to execute. I ran the same commands I tried before and there was no problem.
Guess the question remains, why it couldn't change from D:/ to C:/ when running commands from Java.
Thanks to everyone for the help

The Java version could work as:
String[] command = {"cmd.exe", "/C", "Start", "/D", "c:\\abc\\def", "c:\\abc\\def\\coolBat.bat"};
Process process = Runtime.getRuntime().exec(command);
BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
while ((line = input.readLine()) != null) {
System.out.println(line);
}
input.close();
BufferedReader errReader = new BufferedReader(new InputStreamReader(process.getErrorStream()));
while ((line = errReader.readLine()) != null) {
System.out.println(line);
}
System.out.flush();
int retCode = process.waitFor();
System.out.println("Return code: " + retCode);

Try this:
String[] command = { "cmd.exe", "/C", "C: && C:/abc/def/coolBat.bat" };

Java program not getting output from terminal

I am running my Java program from terminal and I am trying to count the number of files in a certain directory using a linux command in my code; I have managed to get output for all other commands but this one.
My command is: ls somePath/*.xml | wc -l
When I run my command in my code, it appears that it has nothing to output, yet when I run the same exact command in terminal it works just fine and actually outputs the number of xml files in that directory.
Here is my code:
private String executeTerminalCommand(String command) {
String s, lastOutput = "";
Process p;
try {
p = Runtime.getRuntime().exec(command);
BufferedReader br = new BufferedReader(
new InputStreamReader(p.getInputStream()));
System.out.println("Executing command: " + command);
while ((s = br.readLine()) != null){//it appears that it never enters this loop since I never see anything outputted
System.out.println(s);
lastOutput = s;
}
p.waitFor();
p.destroy();
} catch (Exception e) {
e.printStackTrace();
}
return lastOutput;//returns empty string ""
}
Updated code w/ output
private String executeTerminalCommand(String command) {
String s, lastOutput = "";
try {
Process p = new ProcessBuilder().command("/bin/bash", "-c", command).inheritIO().start();
//Process p = Runtime.getRuntime().exec(command);
BufferedReader br = new BufferedReader(
new InputStreamReader(p.getInputStream()));
System.out.println("Executing command: " + command);
while ((s = br.readLine()) != null){
System.out.println("OUTPUT: " + s);
lastOutput = s;
}
System.out.println("Done with command------------------------");
p.waitFor();
p.destroy();
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("LAST OUTPUT IS: " + lastOutput);
return lastOutput;
}
output:
Executing command: find my/path -empty -type f | wc -l
Done with command------------------------
1
LAST OUTPUT IS:

To execute a pipeline, you have to invoke a shell, and then run your commands inside that shell.
Process p = new ProcessBuilder().command("bash", "-c", command).start();
bash invokes a shell to execute your command and -c means commands are read from string. So, you don't have to send the command as an array in ProcessBuilder.
But if you want to use Runtime then
String[] cmd = {"bash" , "-c" , command};
Process p = Runtime.getRuntime().exec(cmd);
Note: You can check advantages of ProcessBuilder here and features here over Runtime

Executing openssl command using Java runtime [duplicate]

How am I to execute a command in Java with parameters?
I've tried
Process p = Runtime.getRuntime().exec(new String[]{"php","/var/www/script.php -m 2"});
which doesn't work.
String[] options = new String[]{"option1", "option2"};
Runtime.getRuntime().exec("command", options);
This doesn't work as well, because the m parameter is not specified.

See if this works (sorry can't test it right now)
Runtime.getRuntime().exec(new String[]{"php","/var/www/script.php", "-m", "2"});

Use ProcessBuilder instead of Runtime#exec().
ProcessBuilder pb = new ProcessBuilder("php", "/var/www/script.php", "-m 2");
Process p = pb.start();

The following should work fine.
Process p = Runtime.getRuntime().exec("php /var/www/script.php -m 2");

Below is java code for executing python script with java.
ProcessBuilder:
First argument is path to virtual environment
Second argument is path to python file
Third argument is any argumrnt you want to pass to python script
public class JavaCode {
public static void main(String[] args) throws IOException {
String lines = null;
ProcessBuilder builder = new ProcessBuilder("/home/env-scrapping/bin/python",
"/home/Scrapping/script.py", "arg1");
Process process = builder.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while ((lines = reader.readLine())!=null) {
System.out.println("Line: " + lines);
}
}
}
First is virtual environment path

Java runtime's .exec() wont open executable

I am trying to execute another file using Runtime and Process
try
{
Runtime run = Runtime.getRuntime();
Process pro = run.exec("C:\\Users\\user\\Desktop\\file.exe");
}
catch(Exception a)
{
a.printStackTrace();
}
I can enter this command in either run or cmd and am able to open the file but running it through my program it won't open. There are no errors, it just doesn't open.

To better understand what is going on (and it is actually a requirement of the Process class), you need to redirect the input and error streams of your process - and using a ProcessBuilder is the recommended way to start processes:
public static void main(String[] args) throws Exception {
ProcessBuilder pb = new ProcessBuilder("C:\\Users\\user\\Desktop\\file.exe");
runProcess(pb)
}
private static void runProcess(ProcessBuilder pb) throws IOException {
pb.redirectErrorStream(true);
Process p = pb.start();
BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
}

You must do
Process pro = run.exec("C:\\Users\\user\\Desktop\\file.exe",null,"C:\\Users\\user\\Desktop\\");
Please see Run .exe file from Java from file location

Try this way:
String []cmdarray = new String[4];
cmdarray[0] = "cmd";
cmdarray[1] = "/c";
cmdarray[2] = "start";
cmdarray[3] = "C:\\Users\\user\\Desktop\\file.exe";
Runtime.getRuntime().exec(cmdarray);

Try this one, create a batch file ,like start_file.bat.
The content like this:
cd C:\Users\user\Desktop ----- Goto this directory
C: ----- This line is very important
file.exe
Both the two approaches work well.
Runtime r = Runtime.getRuntime();
String []cmdarray = new String[4];
cmdarray[0] = "cmd";
cmdarray[1] = "/c";
cmdarray[2] = "start";
cmdarray[3] = "C:/users/desktop/start_file.bat";
r.exec(cmdarray);
And this one:
r.exec("C:/users/desktop/start_file.bat");
You can read the output from this new process.