Develop Reference

.java file to run another .java (frames) through Process

Real Goal: create a program that calls other programs(lab exercises)
Current goal: Make Main.java run Lab4 a GUI program (Lab4Ans201506159.java - the filename)
Lab4Form and Lab4Intro are forms
here is the Main.java code
public class Main {
public static void main(String[] args) throws IOException {
// TODO code application logic here
Process p,p2,p3,p4;
p = Runtime.getRuntime().exec("javac Lab4Ans201506159.java");
//p3 = Runtime.getRuntime().exec("javac Lab4Ans201506159Form.java");
//p4 = Runtime.getRuntime().exec("javac Lab4Ans201506159Intro.java");
p2 = Runtime.getRuntime().exec("java Lab4Ans201506159");
//p2 = Runtime.getRuntime().exec("Lab4Ans201506159");
}
and here is the Lab4 code
Lab4Form and Lab4Intro are Frames
what Lab4 is trying to do displaying Lab4Intro, and when it is closed, Lab4Form would be visible
public class Lab4Ans201506159 {
public static void main(String[] args) throws InterruptedException {
Lab4Ans201506159Intro intro = new Lab4Ans201506159Intro();
intro.setLocationRelativeTo(null);
intro.setVisible(true);
Thread.sleep(2000);
//Lab4Ans201506159Form form = new Lab4Ans201506159Form();
while(intro.isActive())
{
}
if(intro.isActive() == false){
Lab4Ans201506159Form form = new Lab4Ans201506159Form();
form.setLocationRelativeTo(null);
form.setVisible(true);
}
}
Problem: Running Main.java will result to a "BUILD SUCCESSFUL" in the compiler but no GUI is displayed. I need answers why it does not display or work.

I suspect only the first Process is executed, in order to be sure, have you already tried to redirect the output of Runtime.exec to the standard output
something like that:
public static void main(String[] args) throws Exception {
System.setOut(new PrintStream(new FileOutputStream("log.txt")));
System.out.println("Init...");
try {
String line;
Process p = Runtime.getRuntime().exec( "javac Lab4Ans201506159.java" );
BufferedReader in = new BufferedReader(
new InputStreamReader(p.getInputStream()) );
while ((line = in.readLine()) != null) {
System.out.println(line);
}
in.close();
}
Thread.sleep(1000);
Process p2 = Runtime.getRuntime().exec("java Lab4Ans201506159" );
BufferedReader in2 = new BufferedReader(
new InputStreamReader(p2.getInputStream()) );
while ((line = in2.readLine()) != null) {
System.out.println(line);
}
in2.close();
}
catch (Throwable e) {
e.printStacktrace();
}
}
like that you can verify what is going wrong...
good luck

I managed to finish my end goal which is to open Lab4. I sort of took a different method though. I suspect one of the reasons why it does not work is because my classpath must have been wrong. I could say that because I can't compile (javac) in CMD Prompt. So I fixed that, then I 'clean and build' (using Netbeans) the project(lab4,intro,form). After that, in the last line of the compiler there will be a line like "java -jar C:\sdfsafs\blablabal". That was the line I used inside runtime.exec() and it finally worked.
public static void main(String[] args) throws Exception {
try {
runProcess("java -jar \"C:\\Users\\Aldrin\\Desktop\\201506159AnsLab4\\dist\\201506159AnsLab4.jar\"");
//runProcess("dir");
//runProcess("java Lab4Ans201506159");
} catch (Exception e) {
e.printStackTrace();
}
}
I still have not answered why the original code does not work though.

How to execute a bash script from java program

I would like my Java program to execute a bash script and return the output back to Java. The trick is my script starts some sort of 'interactive session' and I suppose that is why my Java application freezes (Enters an infinite loop I suppose). Here is the code I use to execute the script, I use ProcessBuilder in order to do that. I also tried
Runtime.getRuntime().exec(PathToScript);
It doesn't work either.
public class test1 {
public static void main(String a[]) throws InterruptedException, IOException {
List<String> commands = new ArrayList<String>();
List<String> commands1 = new ArrayList<String>();
commands.add("/Path/To/Script/skrypt3.sh");
commands.add("> /dev/ttys002");
ProcessBuilder pb = new ProcessBuilder(commands);
pb.redirectErrorStream(true);
try {
Process prs = pb.start();
Thread inThread = new Thread(new In(prs.getInputStream()));
inThread.start();
Thread.sleep(1000);
OutputStream writeTo = prs.getOutputStream();
writeTo.write("oops\n".getBytes());
writeTo.flush();
writeTo.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
class In implements Runnable {
private InputStream is;
public In(InputStream is) {
this.is = is;
}
#Override
public void run() {
try {
byte[] b = new byte[1024];
int size = 0;
while ((size = is.read(b)) != -1) {
System.out.println(new String(b));
}
is.close();
} catch (IOException ex) {
Logger.getLogger(In.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
And here is the script I try to execute. It works like a charm when I run it directly from terminal.
#!/bin/bash
drozer console connect << EOF > /dev/ttys002
permissions
run app.package.info -a com.mwr.example.sieve
exit
EOF

You should not be trying to add redirect instructions as part of the command name:
commands.add("/Path/To/Script/skrypt3.sh");
commands.add("> /dev/ttys002");
ProcessBuilder pb = new ProcessBuilder(commands);
Instead, use the redirectOutput method, something like this:
tty = new File("/dev/ttys002");
ProcessBuilder pb = new ProcessBuilder("/Path/To/Script/skrypt3.sh")
.redirectOutput(ProcessBuilder.Redirect.appendTo(tty))
.redirectError(ProcessBuilder.Redirect.appendTo(tty))
.start();
Though, it appears your bash script is already handling the redirection so not sure you need to do that in Java.
See this answer for more info.

Execute the command julia.exe in Java

I'm trying to execute julia.exe in Java.
Here is the code:
Process pTest = Runtime.getRuntime().exec("C:/Program Files/Julia-0.4.1/bin/julia.exe");
When I run it, nothing happens.
However, if I try another executable file, it works well. For example:
Process pTest = Runtime.getRuntime().exec("C:/Program Files/anotherProgram/program.exe");
program.exe will run just as expected.
julia.exe is a little special.
If I run it on command prompt, it will execute on the command prompt. In other words, it won't pop up its own window.
I've done a test:
#julia script, it's path: C:/Users/Thomas/Julia/test.jl
function test1()
println("it's test1")
end
test1()
I execute this command on the command prompt:
C:\>C:/Program Files/Julia-0.4.1/bin/julia.exe C:/Users/Thomas/Julia/test.jl
then I will get it's test1 on the command prompt.
What I need is to execute C:/Program Files/Julia-0.4.1/bin/julia.exe C:/Users/Thomas/Julia/test.jl in my java project and get it's test1 on the console of eclipse.
Here is my java project:
public class Main {
public static void main(String[] args){
try {
String[] params = {"C:/Program Files/Julia-0.4.1/bin/julia.exe", "C:/Users/Thomas/Julia/test.jl"};
Process pTest = Runtime.getRuntime().exec(params);
try {
if (pTest.waitFor() != 0) {
System.err.println("exit value = " + pTest.exitValue());
}
BufferedReader in = new BufferedReader(new InputStreamReader(pTest.getInputStream()));
StringBuffer stringBuffer = new StringBuffer();
String line = null;
while ((line = in.readLine()) != null) {
stringBuffer.append(line+"-");
}
System.out.println(stringBuffer.toString());
} catch (InterruptedException e) {
System.err.println(e);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

Consider this changed (and working) implementation removing the too-early invocation of waitFor and exitValue:
public class Main {
public static void main(String[] args) {
try {
String[] params = {"C:/Program Files/Julia-0.4.1/bin/julia.exe",
"C:/Users/Thomas/Julia/test.jl"};
Process pTest = Runtime.getRuntime().exec(params);
BufferedReader in = new BufferedReader(new InputStreamReader(pTest.getInputStream()));
String line = null;
while ((line = in.readLine()) != null) {
System.out.println(line);
}
System.out.println("===");
System.out.println("Julia exit value = " + pTest.exitValue());
} catch (IOException e) {
e.printStackTrace();
}
}
}
This produced the following output with your test-script:
it's test1
===
Julia exit value = 0

I got it finally.
As julia.exe execute on the command prompt immediately, we must give admin privileges to the users of cmd.exe.

getRuntime().exec() does nothing

I want a java program to execute the following shell command:
apktool.jar d /path/to/my/app.apk
This command perfectly works when executing it directly on command line.
Java Code:
public static void main(String[] args) {
String command = "apktool d /path/to/my/app.apk";
try {
Runtime.getRuntime().exec(command);
} catch (IOException e1) {
e1.printStackTrace();
}
}
There is no error, no exception. Nothing happens and i have the impression that I already searched the entire internet for a solution. Does anybody know what I am doing wrong? A simple command like
mkdir /path/to/a/new/folder
works without problems.
I tried the same using ProcessBuilder:
try {
Process process = new ProcessBuilder(command).start();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
This time i only get "Cannot run program "apktool d /path/to/my/app.apk, No such file or directory". I can't even run the mkdir command.

You need to call the jar with java.exe, and you're not doing that. Also you need to trap the input and error streams from the process, something you can't do the way you're running this. Use ProcessBuilder instead, get your streams and then run the process.
For example (and I can only do a Windows example),
import java.io.IOException;
import java.io.InputStream;
import java.util.Scanner;
public class ProcessEg {
private static Process p;
public static void main(String[] args) {
String[] commands = {"cmd", "/c", "dir"};
ProcessBuilder pBuilder = new ProcessBuilder(commands);
pBuilder.redirectErrorStream();
try {
p = pBuilder.start();
InputStream in = p.getInputStream();
final Scanner scanner = new Scanner(in);
new Thread(new Runnable() {
public void run() {
while (scanner.hasNextLine()) {
System.out.println(scanner.nextLine());
}
scanner.close();
}
}).start();
} catch (IOException e) {
e.printStackTrace();
}
try {
int result = p.waitFor();
p.destroy();
System.out.println("exit result: " + result);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

Try doing it like this:
StringBuffer output = new StringBuffer();
Process p;
try {
p = Runtime.getRuntime().exec("./path/apktool d /path/to/my/app.apk");
p.waitFor();
BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = "";
while ((line = reader.readLine())!= null) {
output.append(line + "\n");
}
} catch (Exception e) {
e.printStackTrace();
}
system.out.println(output.toString());
Creating first a process allows you to wait for a response and reads the output of the execution of your process.
If something is failing while running your shell command, you will have the error printed at the end.
Also, make sure your java program can access your shell script, or better provide the full path to it like:
./path/to/shell/apktool d /path/to/my/app.apk

Execute java file with Runtime.getRuntime().exec()

This code will execute an external exe application.
private void clientDataActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try {
Runtime.getRuntime().exec("C:\\Program Files (x86)\\VideoLAN\\VLC\\vlc.exe");
} catch(Exception e) {
System.out.println(e.getMessage());
}
}
What if I want to execute external java file? Is it possible? For example like this command:
Runtime.getRuntime().exec("cmd.exe /C start cd \"C:\Users\sg552\Desktop\ java testfile");
The code does not work from java and cmd prompt. How to solve this?

First, you command line looks wrong. A execution command is not like a batch file, it won't execute a series of commands, but will execute a single command.
From the looks of things, you are trying to change the working directory of the command to be executed. A simpler solution would be to use ProcessBuilder, which will allow you to specify the starting directory for the given command...
For example...
try {
ProcessBuilder pb = new ProcessBuilder("java.exe", "testfile");
pb.directory(new File("C:\Users\sg552\Desktop"));
pb.redirectError();
Process p = pb.start();
InputStreamConsumer consumer = new InputStreamConsumer(p.getInputStream());
consumer.start();
p.waitFor();
consumer.join();
} catch (IOException | InterruptedException ex) {
ex.printStackTrace();
}
//...
public class InputStreamConsumer extends Thread {
private InputStream is;
private IOException exp;
public InputStreamConsumer(InputStream is) {
this.is = is;
}
#Override
public void run() {
int in = -1;
try {
while ((in = is.read()) != -1) {
System.out.println((char)in);
}
} catch (IOException ex) {
ex.printStackTrace();
exp = ex;
}
}
public IOException getException() {
return exp;
}
}
ProcessBuilder also makes it easier to deal with commands that might contain spaces in them, without all the messing about with escaping the quotes...