How to execute shell command from Java

I used the same (similar) code for my ShellWrapper. When I use commands like echo it works fine, but when I use commands like cat it returns an empty String….

Now..How do I do this – execute shell command from java – from in-app text (i.e. via link)?

I want to link existing text, in an app, to ‘ test.sh ‘, but am having issue making the link. The .sh only contains one line of shell script ( a simple ‘ pm enable {packagename} ‘ command ). Would it be easier to put the command somewhere, or use the ‘ test.sh ‘ var?

The best option is to make a link from text in an existing app (decompiled and manipulated in .smali dorm, via ‘APKEditor)… This was posted on a couole of sites, without solution.

Hope you can help; cheers!

hey, a bit of context: I am implementing a java library which is used as .jar inside an android project. So the phone is connected over usb to customized android device. Already working, I have other functions doing some other job.
This function is to send a file to the customized android device, using adb push command.

adb push file_path destination_path
but it seems not to work, do you have some idea? I appreciate your feedback

I want to connect to DB in unix using java application and i have requirement while trying to connect with go to some specific location and then run java connection code ?
Coudl you please help me on this ?

Hi ,

i want to write a java class which will be deployed on a server .java class has to perform
1.listing out docker containers and login to particular docker image.
2.after logging it has to execute two commands in docker image

can anyone please help

I need to execute a custom unix command to run a process and it will take around 10sec for the process to run. How to do it.

Hello,

I want to execute 2 commands in a sequence.
1. cd D://
2. java -jar -role hub

I tried below code but it tries to execute jar file first and then cd :

ProcessBuilder builder = new ProcessBuilder(“cmd”,”/c”,”start”,”cmd.exe”,”/K”, “java -jar -role hub && cd \”D:\\””);
builder.redirectErrorStream(true);
Process p = builder.start();

any suggestion for first cd should get execute and then .jar?

let’s say we type ‘mysql’ in command prompt.

c:mysql
then the prompt changes to:
mysql>
now in this we type sql commands.
Can we achieve/automate this with java?

The following code allows you to set a timer, restart the timer on keywords, and specify if you want it to be sent to your log or not. This prevents several problems I’ve run into while programming on the command line.

The method is complex, very complex, but it works well and avoids loops in favor of waiting for a synchronized notification whenever possible. It uses three threads. The main thread launches the application and waits. The reader thread processes whatever comes out of the application. The watchdog thread monitors for timeout and gets kicked by the reader thread to restart the timer whenever a keyword is detected.

public String timeoutValueCheckingShellCommand(final String[] cmd, final String[] restartTimerKeywords, final int timeout,final boolean logLevel2) {

StringBuilder sb = new StringBuilder();

try {

ProcessBuilder p = new ProcessBuilder(cmd);

p=p.redirectErrorStream(true);

final Process process = p.start();

/*

TimeoutLogger is a place to hold a common object for use through

the various threads. It is used for logging of data, locking the

main thread on the processRunning object, timeout status and

monitoring of if the thread is alive or not.

*/

class TimeoutLogger {

TimeoutLogger(boolean realtime,Process p){

this.realtime=realtime;

this.processRunning=p;

}

boolean realtime;

private final StringBuilder log = new StringBuilder();

AtomicBoolean timedOut = new AtomicBoolean(false);

AtomicBoolean isRunning = new AtomicBoolean(true);

final Object isRunningLock=new Object();

AtomicBoolean isLogging = new AtomicBoolean(true);

final Object isLoggingLock=new Object();

final Process processRunning;

final Timer watchDogTimer = new Timer(timeout, new ActionListener() {

@Override

public void actionPerformed(ActionEvent evt) {

Log.level4Debug(“Watchdog Triggered! Command timed out.”);

timedOut.set(true);

synchronized (processRunning) {

processRunning.notifyAll();

}

}

});

synchronized void log(char c){

log.append(c);

if (realtime){

Log.progress(Character.toString(c));

String logstring=log.toString();

for (String check:restartTimerKeywords){

if (logstring.endsWith(check) && isRunning.get()){

Log.level4Debug(“Timer Reset on keyword “+check);

watchDogTimer.restart();

}

}

}

}

synchronized String get(){

return log.toString();

}

}

final TimeoutLogger tl = new TimeoutLogger(logLevel2,process);

/*if the watchDogtimer elapses, the timedOut boolean is set true

and the processRunning object is notified to release main process

wait.

*/

/*notify the processRunning object when the thread is complete to

release the lock.

*/

Thread processMonitor = new Thread(new Runnable() {

@Override

public void run() {

try {

tl.processRunning.waitFor();

tl.watchDogTimer.stop();

tl.isRunning.set(false);

Log.level4Debug(“Process Monitor done.”);

synchronized (tl.processRunning) {

tl.processRunning.notifyAll();

}

} catch (InterruptedException ex) {

Logger.getLogger(Shell.class.getName()).log(Level.SEVERE, null, ex);

}

}

});

processMonitor.setName(“Monitoring Process Exit Status from ” + cmd[0]);

/*

reads the output and restarts the timer if required.

*/

Thread reader = new Thread(new Runnable() {

@Override

public void run() {

BufferedInputStream STDOUT = new BufferedInputStream(tl.processRunning.getInputStream());

Log.level4Debug(“Instantiating reader process”);

try {

while(tl.isRunning.get()&& !tl.timedOut.get()){

if(STDOUT.available()>0){

char read=(char)STDOUT.read();

tl.log(read);

}

}

tl.watchDogTimer.stop();

Thread.sleep(100);

while(STDOUT.available()>0){

char read=(char)STDOUT.read();

tl.log(read);

}

tl.isLogging.set(false);

synchronized (tl.processRunning){

tl.processRunning.notifyAll();

}

} catch (IOException ex) {

Logger.getLogger(Shell.class.getName()).log(Level.SEVERE, null, ex);

} catch (InterruptedException ex) {

Logger.getLogger(Shell.class.getName()).log(Level.SEVERE, null, ex);

}

}

});

reader.setName(“Reading and monitoring output from ” + cmd[0]);

//start the monitoring objects

reader.start();

tl.watchDogTimer.start();

processMonitor.start();

synchronized (tl.processRunning){

tl.processRunning.wait();

}

if (tl.isLogging.get()){

synchronized(tl.processRunning){

tl.processRunning.wait();

}

}

String retvalue = tl.get();

//kill the process

if (tl.timedOut.get()) {

retvalue = “Timeout!!! ” + retvalue;

process.destroy();

}

return retvalue;

} catch (IOException ex) {

Logger.getLogger(Shell.class.getName()).log(Level.SEVERE, null, ex);

} catch (InterruptedException ex) {

Logger.getLogger(Shell.class.getName()).log(Level.SEVERE, null, ex);

}

return “”;

}