I have a problem with running ruby script in spring framework.
Let's say I have a script named 'my_script.rb', when I run it from terminal it works perfectly normal. When I execute it in "normal" java program:
public class RubyExecutor {
public static String execute(String command){
StringBuilder output = new StringBuilder();
Process p;
try {
p = Runtime.getRuntime().exec(command);
p.waitFor();
BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
output.append(line).append("\n");
}
} catch (Exception e) {
e.printStackTrace();
}
return output.toString();
}
public static void main(String[] args){
System.out.println(RubtExecutor.execute("ruby /home/wookash/script.rb \"/home/wookash/rubyScripts\" \"case_0/\""));
}
script still works.
Problem comes when I put mentioned-above code in spring app.
What is weird: literally half of ruby script runs, magicly second half of lines of code is not being executed, no matter what is there. No errors, no warnings, nothing. I'm guessing that is caused by Spring task execution framework. However i have no idea how to fix it. Thank You in advance.
//EDIT I am pasting my spring method.
#RequestMapping("/execute")
public void executeCmd(){
executeCommand("ruby /home/wookash/script.rb \"/home/wookash/rubyScripts\" \"case_0/\"");
}
private String executeCommand(String command) {
StringBuilder output = new StringBuilder();
Process p;
try {
p = Runtime.getRuntime().exec(command);
p.waitFor();
BufferedReader reader =
new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = reader.readLine()) != null) {
output.append(line).append("\n");
}
} catch (Exception e) {
e.printStackTrace();
}
return output.toString();
}
Related
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
I'm implementing custom script rule plugin for Sonar.
I want to make a checking rule directly for the source code
and not from checking tokens or nodes of the ASTtree.
Having the follow code:
#Override
public void visitFile() {
BufferedReader br = null;
File file = null;
String line = null;
try {
file = this.getSourceCode().getFile();
br = new BufferedReader(new FileReader(file));
while ((line = br.readLine()) != null) {
...
}
}
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
My problem is that the :
this.getSourceCode().getFile();
returns back null
how can I get the instance of the file for which was actually the visitFile() called?
How does 'visitFile()' works actually?
So I'm starting a Bukkit (Minecraft) server from a GUI.
ProcessBuilder builder = new ProcessBuilder();
builder.redirectErrorStream(true);
builder.command("java", "-jar", file.getAbsolutePath());
try {
p = builder.start();
input = new BufferedReader(new InputStreamReader(p.getInputStream()));
output = new DataOutputStream(p.getOutputStream());
} catch (IOException e) {
Logger.logError(e);
return;
}
There are no errors, and the server itself starts correctly. The input stream works correctly too, as I get all the input as I should. Now, I have this method to send a command to the server.
public void send(String message) {
try {
output.writeUTF(message + "\n");
output.flush();
} catch (IOException e) {
Logger.logError(e);
}
}
For some reason though, it doesn't work. I'm not sure if I missed a step, or am looking over something, etc. Any help would be greatly appreciated!
I suspect the DataOutputStream is writing data in a non-conventional way towards the OutputStream, try using a PrintWriter object instead.
Consider this:
try {
p = builder.start();
input = new BufferedReader(new InputStreamReader(p.getInputStream()));
output = new PrintWriter(p.getOutputStream());
} catch (IOException e) {
Logger.logError(e);
return;
}
The Send method:
public void send(String message) {
output.println(message);
output.flush();
}
P.S You no longer need the try-catch around the output.println() as PrintWriter's print and println methods don't throw IOException.
From bukkit's plugin perspective (read my comment if you have no clue what this is):
final JavaPlugin Inst = ... //This plugin's object
try(BufferedReader Reader = new BufferedReader(new InputStreamReader(System.in, Charset.forName("UTF-8")))){
while((Line = Reader.readLine()) != null){
final String L = Line;
Bukkit.getScheduler().runTask(Inst, new Runnable(){
#Override
public void run() {
Bukkit.dispatchCommand(Bukkit.getConsoleSender(), L);
}
});
}
}catch(IOException ex){
//Handle this
}
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 ();
}
}
I want to write a Java program that runs an external "java myprog < input.txt > output.txt" command. The eventual goal is to run this command on two different programs and compare their output similarity from their respective output files.
I think I've read just about every relevant article about using ProcessBuilder to run an external program, and the few entries about handling user input in that external program, but I still can't get things working. From what I have read, I think the best approach is to not run the exact command above, but instead read the input.txt file and feed it byte-by-byte into the Process object, then collect the output and write it to output.txt ... I am 100% open to other options.
I put together the code below based on my readings. It seems to correctly feed input from input.txt into myprog, but when I try to print the external program's output to the console to verify, the program hangs at the point where (surprise) user input is expected in myprog.
I get the same issues with and without the redirectErrorStream(true) line.
I really want this to be in Java since I plan to share the source code with the people whose program outputs I will compare, and they are primarily only familiar with Java.
import java.io.*;
import java.util.*;
public class test7 {
public static void main(String args[]) {
try {
// WANT: "java myprog < input.txt > output.txt"
String inputFile = "input.txt";
String outputFile = "output.txt";
ProcessBuilder pb = new ProcessBuilder("java","myprog");
pb.redirectErrorStream(true); // merge stdout, stderr of process
Process p = pb.start();
// write input to the running program
OutputStream pos = p.getOutputStream();
InputStream fis = new FileInputStream(inputFile);
int read = 0;
while ( (read = fis.read()) != -1) {
pos.write(read);
}
fis.close();
// get output of running program
InputStreamReader isr = new InputStreamReader(p.getInputStream());
BufferedReader br = new BufferedReader(isr);
// HANGS HERE WHEN USER INPUT REQUIRED
String lineRead;
while ((lineRead = br.readLine()) != null) {
System.out.println(lineRead);
}
}
catch (IOException e) {
e.printStackTrace();
}
} // end main
}
Here is the content of myprog.java:
import java.io.*;
public class myprog {
public static void main(String args[]) throws IOException {
System.out.println("Hello world!");
System.out.println("Enter something:");
BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));
// the readLine() command causes ProcessBuilder to hang
cin.readLine();
}
}
And the input.txt file is just
p
The output.txt file should be
Hello world!
Enter something:
I wonder if your problem is partly to do with not using separate threads for reading input and writing output. For instance:
public static void main(String args[]) {
try {
// WANT: "java myprog < input.txt > output.txt"
String inputFile = "input.txt";
String outputFile = "output.txt";
// my ProcessBuilder Strings will be different from yours
ProcessBuilder pb = new ProcessBuilder("java", "-cp", ".;bin;",
"yr12.m04.a.MyProg");
pb.redirectErrorStream(true);
Process p = pb.start();
final OutputStream pos = p.getOutputStream();
final PrintWriter pw = new PrintWriter(pos);
final InputStream fis = new FileInputStream(inputFile);
final BufferedReader fileBr = new BufferedReader(new InputStreamReader(fis));
InputStreamReader isr = new InputStreamReader(p.getInputStream());
final BufferedReader br = new BufferedReader(isr);
new Thread(new Runnable() {
public void run() {
String lineRead;
try {
while ((lineRead = br.readLine()) != null) {
System.out.println(lineRead);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (br != null) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}).start();
new Thread(new Runnable() {
public void run() {
try {
String lineRead;
while ((lineRead = fileBr.readLine()) != null) {
pw.println(lineRead);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (pw != null) {
pw.close();
}
if (fileBr != null) {
try {
fileBr.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}).start();
} catch (IOException e) {
e.printStackTrace();
}
} // end main
Have you thought about using Runtime.getRuntime().exec() instead?
Process proc = Runtime.getRuntime().exec("java myprog "+inputFile+" "+outputFile);
You could include the jar of the 'myprog' and call the main() method yourself. Even more so if myprog is in your domain you could get rid of the main method altogether.