Develop Reference

Java.io.Exception: Working Directory: null Environment: null

I am trying to run a shell command from my application directory and I am getting "working directory null and environment null.
I have looked at several posts here but I'm not quite sure where to go from here.
Error:
Error running exec(). Command: [/data/user/0/com.netscout.iperf3_clientls] Working Directory: null Environment: null
public void startApp() {
StringBuffer output = new StringBuffer();
Process process = null;
String appFileDir = getApplicationInfo().dataDir;
// String commandLine = appFileDir + "/iperf3 -c 129.196.197.116 --forceflush -O3 -Z -P2";
String commandLine = appFileDir + "ls";
try {
process = Runtime.getRuntime().exec(commandLine, null, null);
BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = "";
while ((line = reader.readLine())!= null) {
// output.append(line + "/n");
Log.e("Line", String.valueOf(line));
Log.e("output", String.valueOf(output));
}
} catch (IOException e) {
e.printStackTrace();
Log.i("Output", String.valueOf(e));
}
}

Try setting a working directory for the script to run from. Also I would suggest to use a ProcessBuilder for doing your job:
https://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html

Making my own Java IDE

I am trying to make my own Java IDE, however i am having problems getting the input from user after displaying the program itself
I have so far tried 2 ways of getting the console to appear.
Using Create Java console inside a GUI panel
or using my own code of
void runCommand(String command)
{
try {
ProcessBuilder builder = new ProcessBuilder(
"cmd.exe", "/c", command);
builder.redirectErrorStream(true);
Process p = builder.start();
BufferedReader r = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while (true) {
line = r.readLine();
if (line == null) { break; }
System.out.println(line);
}
} catch (IOException ex) {
Logger.getLogger(FileToClass2.class.getName()).log(Level.SEVERE, null, ex);
}
}
void createClass(String dir, String filename)
{
//TODO: stop using exact java path / compile all .java in a dir
runCommand("cd "+dir+" && \"C:\\Program Files\\Java\\jdk1.8.0_91\\bin\\javac\" " + filename);
}
void runClass(String dir, String filename)
{
//TODO: allow use of packages etc
runCommand("cd " + dir + " && java " + filename);
}
This above code simply gets the output of the cmd terminal, the problem both these approaches have is the lack of input say if the user wanted to do a Scanner nextLine()
Is there any solution to this?

Running terminal commands throug java

I have to execute two commands in terminal from my java program. Here is the java code that I am using :
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Runterminal {
public static void main(String[] args) {
Process proc;
Process procRun;
String compileCommand = "aarch64-linux-g++ -std=c++14 hello.cpp";
String runCommand = "aarch64-linux-objdump -d a.out";
try{
proc = Runtime.getRuntime().exec(compileCommand);
procRun = Runtime.getRuntime().exec(runCommand);
// Read the output
BufferedReader reader =
new BufferedReader(new InputStreamReader(proc.getInputStream()));
String line = "";
while((line = reader.readLine()) != null) {
System.out.print(line + "\n");
}
proc.waitFor();
BufferedReader readero =
new BufferedReader(new InputStreamReader(procRun.getInputStream()));
String lineo = "";
while((lineo = readero.readLine()) != null) {
System.out.print(lineo + "\n");
}
procRun.waitFor();
}
catch(Exception e)
{
System.out.println("Exception occurred "+e);
}
}
}
My hello.cpp file is stored in the home directory. When I compile the java program it gets compiled but while running it it is throwing exception. Here's the output which I am getting :
Exception occurred java.io.IOException: Cannot run program "aarch64-
linux-g++": error=2, No such file or directory

Try to replace using following lines in your code,
String compileCommand = "g++ -std=c++14 hello.cpp";
String runCommand = "./a.out";
And keep the .cpp file in same directory where the .class file lies.

Executing "$ aarch64-linux-objdump -d a.out' in terminal throug java

I have made a cross compiler using gcc. Now I want the compile and run commands to be executed in a terminal through java program. Here is the code that I am using for this :
import java.io.BufferedReader;
import java.io.InputStreamReader;
public class Runterminal {
public static void main(String[] args) {
Process proc;
Process procRun;
String compileCommand = "aarch64-linux-g++ -std=c++14 test.cpp";
String runCommand = "aarch64-linux-objdump -d a.out";
try{
proc = Runtime.getRuntime().exec(compileCommand);
procRun = Runtime.getRuntime().exec(runCommand);
// Read the output
BufferedReader reader =
new BufferedReader(new InputStreamReader(proc.getInputStream()));
String line = "";
while((line = reader.readLine()) != null) {
System.out.print(line + "\n");
}
proc.waitFor();
BufferedReader readero =
new BufferedReader(new InputStreamReader(procRun.getInputStream()));
String lineo = "";
while((lineo = readero.readLine()) != null) {
System.out.print(lineo + "\n");
}
procRun.waitFor();
}
catch(Exception e)
{
System.out.println("Exception occurred "+e);
}
}
}
Now my first command is executing since I could see the a.out file being generated. The second command should dump the memory contents of file and it should print in in terminal but I am not seeing any output. Can anyone tell where I am going wrong?

Pass filename for command execution

I am searching files based on extension. Now for each file found, want to run a command:
Lets assume file found: C:\Home\1\1.txt. My exe exists in: C:\Home\Hello.exe
I would like to run command something like: "C:\Home\Hello.exe C:\Home\1\1.txt"
similarly for C:\Home\ABC\2.txt - "C:\Home\Hello.exe C:\Home\ABC\2.txt"
Kindly help me how to pass a searched file as an input to execute a command.
Thanks,
Kino

You can use below program as a base and then customize further as per your rqeuirement
public class ProcessBuildDemo {
public static void main(String [] args) throws IOException {
String[] command = {"CMD", "/C", "dir"}; //In place of "dir" you can append the list of file paths that you have
ProcessBuilder probuilder = new ProcessBuilder( command );
//You can set up your work directory
probuilder.directory(new File("c:\\xyzwsdemo")); //This is the folder from where the command will be executed.
Process process = probuilder.start();
//Read out dir output
InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
String line;
System.out.printf("Output of running %s is:\n",
Arrays.toString(command));
while ((line = br.readLine()) != null) {
System.out.println(line);
}
//Wait to get exit value
try {
int exitValue = process.waitFor();
System.out.println("\n\nExit Value is " + exitValue);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

Lets get you started:
Filter files using: FilenameFilter:
http://docs.oracle.com/javase/7/docs/api/java/io/FilenameFilter.html
Sample:
http://www.java-samples.com/showtutorial.php?tutorialid=384
And after you have got the files:
Use ProcessBuilder to execute:
http://docs.oracle.com/javase/7/docs/api/java/lang/ProcessBuilder.html
Sample:
http://www.xyzws.com/Javafaq/how-to-run-external-programs-by-using-java-processbuilder-class/189

If you are running your app from the command line (e.g. windows cmd), and your program name is Hello.java, only thing you have to do is to put in the argument, just like you did in your example. So it looks something like:
java Hello C:\Home\1\1.txt
I did not use exe, since this is an example, and the question is tagged with "java" tag.
Your Hello.java MUST have a main method that looks like this:
public static void main(String ... args) {
}
The parameter args are the actual parameters you enter in the command line. So to get the file name, you would have to do this:
public static void main(String ... args) {
String fileName= args[0];
}
And that's it. Later on, you can do with that whatever you want, i.e. open and edit a file:
File file= new File(fileName);
//do whatever with that file.

This code will help you
public static void main(String args[]) {
String filename;
try {
Runtime rt = Runtime.getRuntime();
filename = "";//read the file na,e
Process pr = rt.exec("C:\\Home\\Hello.exe " + filename );
BufferedReader input = new BufferedReader(new InputStreamReader(pr.getInputStream()));
String line=null;
while((line=input.readLine()) != null) {
System.out.println(line);
}
int exitVal = pr.waitFor();
System.out.println("Error "+exitVal);
} catch(Exception e) {
System.out.println(e.toString());
e.printStackTrace();
}
}