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Is it possible to execute java -jar programmatically? [duplicate]

I found several code snippets for running cmd commands through a Java class, but I wasn't able to understand it.
This is code for opening the cmd
public void excCommand(String new_dir){
Runtime rt = Runtime.getRuntime();
try {
rt.exec(new String[]{"cmd.exe","/c","start"});
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
And I found some other links for adding other commands such as cd
http://www.coderanch.com/t/109753/Linux-UNIX/exec-command-cd-command-java
How to open the command prompt and insert commands using Java?
Can anyone help me to understand how to cd a directory such as:
cd C:\Program Files\Flowella
then run other commands on that directory?

One way to run a process from a different directory to the working directory of your Java program is to change directory and then run the process in the same command line. You can do this by getting cmd.exe to run a command line such as cd some_directory && some_program.
The following example changes to a different directory and runs dir from there. Admittedly, I could just dir that directory without needing to cd to it, but this is only an example:
import java.io.*;
public class CmdTest {
public static void main(String[] args) throws Exception {
ProcessBuilder builder = new ProcessBuilder(
"cmd.exe", "/c", "cd \"C:\\Program Files\\Microsoft SQL Server\" && dir");
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);
}
}
}
Note also that I'm using a ProcessBuilder to run the command. Amongst other things, this allows me to redirect the process's standard error into its standard output, by calling redirectErrorStream(true). Doing so gives me only one stream to read from.
This gives me the following output on my machine:
C:\Users\Luke\StackOverflow>java CmdTest
Volume in drive C is Windows7
Volume Serial Number is D8F0-C934
Directory of C:\Program Files\Microsoft SQL Server
29/07/2011 11:03 <DIR> .
29/07/2011 11:03 <DIR> ..
21/01/2011 20:37 <DIR> 100
21/01/2011 20:35 <DIR> 80
21/01/2011 20:35 <DIR> 90
21/01/2011 20:39 <DIR> MSSQL10_50.SQLEXPRESS
0 File(s) 0 bytes
6 Dir(s) 209,496,424,448 bytes free

You can try this:-
Process p = Runtime.getRuntime().exec(command);

If you want to perform actions like cd, then use:
String[] command = {command_to_be_executed, arg1, arg2};
ProcessBuilder builder = new ProcessBuilder(command);
builder = builder.directory(new File("directory_location"));
Example:
String[] command = {"ls", "-al"};
ProcessBuilder builder = new ProcessBuilder(command);
builder = builder.directory(new File("/ngs/app/abc"));
Process p = builder.start();
It is important that you split the command and all arguments in separate strings of the string array (otherwise they will not be provided correctly by the ProcessBuilder API).

Here is a more complete implementation of command line execution.
Usage
executeCommand("ls");
Output:
12/27/2017 11:18:11:732: ls
12/27/2017 11:18:11:820: build.gradle
12/27/2017 11:18:11:820: gradle
12/27/2017 11:18:11:820: gradlew
12/27/2017 11:18:11:820: gradlew.bat
12/27/2017 11:18:11:820: out
12/27/2017 11:18:11:820: settings.gradle
12/27/2017 11:18:11:820: src
Code
private void executeCommand(String command) {
try {
log(command);
Process process = Runtime.getRuntime().exec(command);
logOutput(process.getInputStream(), "");
logOutput(process.getErrorStream(), "Error: ");
process.waitFor();
} catch (IOException | InterruptedException e) {
e.printStackTrace();
}
}
private void logOutput(InputStream inputStream, String prefix) {
new Thread(() -> {
Scanner scanner = new Scanner(inputStream, "UTF-8");
while (scanner.hasNextLine()) {
synchronized (this) {
log(prefix + scanner.nextLine());
}
}
scanner.close();
}).start();
}
private static SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy hh:mm:ss:SSS");
private synchronized void log(String message) {
System.out.println(format.format(new Date()) + ": " + message);
}

My example (from real project)
folder — File.
zipFile, filesString — String;
final String command = "/bin/tar -xvf " + zipFile + " " + filesString;
logger.info("Start unzipping: {} into the folder {}", command, folder.getPath());
final Runtime r = Runtime.getRuntime();
final Process p = r.exec(command, null, folder);
final int returnCode = p.waitFor();
if (logger.isWarnEnabled()) {
final BufferedReader is = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line;
while ((line = is.readLine()) != null) {
logger.warn(line);
}
final BufferedReader is2 = new BufferedReader(new InputStreamReader(p.getErrorStream()));
while ((line = is2.readLine()) != null) {
logger.warn(line);
}
}

The easiest way would be to use Runtime.getRuntime.exec().
For example, to get a registry value for the default browser on Windows:
String command = "REG QUERY HKEY_CLASSES_ROOT\\http\\shell\\open\\command";
try
{
Process process = Runtime.getRuntime().exec(command);
} catch (IOException e)
{
e.printStackTrace();
}
Then use a Scanner to get the output of the command, if necessary.
Scanner kb = new Scanner(process.getInputStream());
Note: the \ is an escape character in a String, and must be escaped to work properly (hence the \\).
However, there is no executable called cd, because it can't be implemented in a separate process.
The one case where the current working directory matters is executing an external process (using ProcessBuilder or Runtime.exec()). In those cases you can specify the working directory to use for the newly started process explicitly.
Easiest way for your command:
System.setProperty("user.dir", "C:\\Program Files\\Flowella");

Try this:
Process runtime = Runtime.getRuntime().exec("cmd /c start notepad++.exe");

Once you get the reference to Process, you can call getOutpuStream on it to get the standard input of the cmd prompt. Then you can send any command over the stream using write method as with any other stream.
Note that it is process.getOutputStream() which is connected to the stdin on the spawned process. Similarly, to get the output of any command, you will need to call getInputStream and then read over this as any other input stream.

Stopping and Disabling a service can be done via below code:
static void sdService() {
String[] cmd = {"cmd.exe", "/c", "net", "stop", "MSSQLSERVER"};
try {
Process process = new ProcessBuilder(cmd).start();
process.waitFor();
String line = null;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
line = null;
bufferedReader = null;
Process p = Runtime.getRuntime().exec("sc config MSSQLSERVER start= disabled");
p.waitFor();
bufferedReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
Enabling and Starting a service can be done via below code
static void esService() {
String[] cmd = {"cmd.exe", "/c", "net", "start", "MSSQLSERVER"};
try {
Process p = Runtime.getRuntime().exec("sc config MSSQLSERVER start= auto");
//Process p = Runtime.getRuntime().exec("sc config MSSQLSERVER start= demand");
p.waitFor();
String line = null;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
line = null;
bufferedReader = null;
Process process = new ProcessBuilder(cmd).start();
process.waitFor();
bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
Executing command from any folder can be done via below code.
static void runFromSpecificFolder() {
try {
ProcessBuilder processBuilder = new ProcessBuilder("cmd.exe", "/c", "cd \"C:\\Users\\himan\\Desktop\\Java_Test_Deployment\\jarfiles\" && dir");
//processBuilder.directory(new File("C://Users//himan//Desktop//Java_Test_Deployment//jarfiles"));
processBuilder.redirectErrorStream(true);
Process p = processBuilder.start();
p.waitFor();
String line = null;
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(p.getInputStream()));
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String args[]) {
sdService();
runFromSpecificFolder();
esService();
}

You can't run cd this way, because cd isn't a real program; it's a built-in part of the command-line, and all it does is change the command-line's environment. It doesn't make sense to run it in a subprocess, because then you're changing that subprocess's environment — but that subprocess closes immediately, discarding its environment.
To set the current working directory in your actual Java program, you should write:
System.setProperty("user.dir", "C:\\Program Files\\Flowella");

public class Demo {
public static void main(String args[]) throws IOException {
Process process = Runtime.getRuntime().exec("/Users/******/Library/Android/sdk/platform-tools/adb" + " shell dumpsys battery ");
BufferedReader in = new BufferedReader(new InputStreamReader(process.getInputStream()));
String line = null;
while (true) {
line = in.readLine();
if (line == null) { break; }
System.out.println(line);
}
}
}

The simplest and shortest way is to use CmdTool library.
new Cmd()
.configuring(new WorkDir("C:/Program Files/Flowella"))
.command("cmd.exe", "/c", "start")
.execute();
You can find more examples here.

one of the way to execute cmd from java !
public void executeCmd() {
String anyCommand="your command";
try {
Process process = Runtime.getRuntime().exec("cmd /c start cmd.exe /K " + anyCommand);
} catch (IOException e) {
e.printStackTrace();
}
}

Here the value adder is use of ampersands to batch commands and correct format for change drive with cd.
public class CmdCommander {
public static void main(String[] args) throws Exception {
//easyway to start native windows command prompt from Intellij
/*
Rules are:
1.baseStart must be dual start
2.first command must not have &.
3.subsequent commands must be prepended with &
4.drive change needs extra &
5.use quotes at start and end of command batch
*/
String startQuote = "\"";
String endQuote = "\"";
//String baseStart_not_taking_commands = " cmd /K start ";
String baseStart = " cmd /K start cmd /K ";//dual start is must
String first_command_chcp = " chcp 1251 ";
String dirList = " &dir ";//& in front of commands after first command means enter
//change drive....to yours
String changeDir = " &cd &I: ";//extra & makes changing drive happen
String javaLaunch = " &java ";//just another command
String javaClass = " Encodes ";//parameter for java needs no &
String javaCommand = javaLaunch + javaClass;
//build batch command
String totalCommand =
baseStart +
startQuote +
first_command_chcp +
//javaCommand +
changeDir +
dirList +
endQuote;
System.out.println(totalCommand);//prints into Intellij terminal
runCmd(totalCommand);
//Thread t = Thread.currentThread();
//t.sleep(3000);
System.out.println("loppu hep");//prints into Intellij terminal
}
public static void runCmd(String command) throws Exception {
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(command);
}
}

Redirect sh file out put to file using Runtime.getRuntime().exec

I have tried similar suggestions from stack overflow, still issue persist.
I am executing following command from java
public static void main(String[] args) throws Exception {
try {
String line;
//String[] commandToExecute = {"sh" , "MultiDel_FI.sh", " < abcd.log 2>&1 &"};
String[] commandToExecute = {"sh" , "MultiDel_FI.sh"};
Process p = Runtime.getRuntime().exec( commandToExecute );
p.waitFor();
BufferedReader reader = new BufferedReader(
new InputStreamReader(p.getInputStream()));
writer = new FileWriter("redirect.log");
while ((line = reader.readLine()) != null) {
writer.write(line);
}
writer.close();
p.waitFor();
p.destroy();
catch (Exception e) {
//
}
MultiDel_FI.sh file is placed on edge node with following content
hadoop fs -rm -R -skipTrash 'hdfs://<path>/abc_767' 'hdfs://<path>/abc_768' 'hdfs://<path>/abc_769' ...........many more records
when I run the code it successfully removes the folders from HDFS location.
I need to track the output of the command to identify which folder got deleted successfully and which one is not.
I tried various options with bin/sh ,writing inputstream to file, it generates empty file.
Any suggestions please?
direct unix command properly redirects output.
sh MultiDel_FI.sh > abcd.log 2>&1

public static void main(String[] args) throws IOException {
//String[] commandToExecute = {"sh" , "MultiDel_FI.sh"};
String[] commandToExecute = {"beeline", "--force=true", "-u", "jdbc:hive2://<host>:<port>/<hive database>;ssl=true;user=<user>;password=<pw>", "-f", "ppp1.hql"};
ProcessBuilder builder = new ProcessBuilder(commandToExecute);
builder.redirectError(new File("out.txt"));
builder.redirectOutput(new File("out.txt"));
builder.start();
}

Why am I getting IOException : "Cannot run program ./shellScript.sh error = 2, No such file or directory in Java?

The following Main.java code simply tries to simulate the following linux command:
cd /dir1/dir2
./shellScript.sh
The program below works only if the executable Main.jar sits within /dir1/dir2, not outside of /dir1/dir2. How do I modify the program below so that Main.jar can sit anywhere on the file system?
public class Main {
public static String runCmdLineProcess(String commandStr){
String returnVal = "";
Runtime r = Runtime.getRuntime();
try {
Process p = r.exec(commandStr);
BufferedReader b = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = "";
while ((line = b.readLine()) != null){
returnVal += line + "\n";
}
}
catch(IOException ex){
ex.printStackTrace();
}
return returnVal;
}
public static void runProcessBuilder(String scriptPath){
String[] cmd = {scriptPath};
try {
runCmdLineProcess("cd /dir1/dir2");
Runtime.getRuntime().exec(cmd);
}
catch (IOException ex){
ex.printStackTrace();
}
}
public static void main(String[] args){
runProcessBuilder("./shellScript.sh"); // <-- works if I run from inside "/dir1/dir2".
//But if I'm outside "dir2", get an error message
// saying "Cannot run program "./shellScript.sh": error = 2, No such file or directory
}
}

You should use ProcessBuilder to launch or one of the overloads of exec. You need to specify the pathname to the script and pass the same pathname as the current directory to run the script in:
File pwd = new File("/dir1/dir2");
String shell = new File(pwd, "shellScript.sh").toString();
ProcessBuilder pb = new ProcessBuilder(shell);
// No STDERR => merge to STDOUT - or call redirectError(File)
pb.redirectErrorStream(true);
// Set CWD for the script
pb.directory(pwd);
Process p = pb.start();
// Move STDOUT to the output stream (or original code to save as String)
try(var stdo = p.getInputStream()) {
stdo.transferTo(stdout);
}
int rc = p.waitFor();

Runtime.getRuntime.exec() not working for the linux command "tar -xvf filename.tar"

I am trying to untar a file on a Unix machine, using a Java batch application.
Source Code:
String fileName = "x98_dms_12";
Runtime.getRuntime().exec("gunzip "+ fileName + ".tar.gz");
System.out.println(" Gunzip:"+"gunzip "+ fileName + ".tar.gz");
Runtime.getRuntime().exec("tar -xvf "+ fileName + ".tar");
System.out.println(" Extract:tar -xvf "+ fileName + ".tar");
Problem Description:
When I run the batch program it does not (completely) work. Only the gunzip command works, converting my fileName.tar.gz to fileName.tar. But the untar command does not seem to do anything, and there is no error or exception in my log or Unix console.
When I run the same commands in a Unix prompt they work fine.
Notes:
The path of execution is correct because it converts my *.tar.gz to *.tar
I cannot use "tar -zxvf fileName.tar.gz" since the attribute "z" does not work on my system.
There is no error or exception thrown.
Please do help.

A couple of things:
The tar command will expand a file relative to your working directory, which might need to be set for your Java Process objects
You should wait for the unzip process to complete before launching into the untar process
You should process the output streams from the processes.
Here is a working example that you can extend/adapt. It uses a separate class to deal with the process output streams:
class StreamGobbler implements Runnable {
private final Process process;
public StreamGobbler(final Process process) {
super();
this.process = process;
}
#Override
public void run() {
try {
final BufferedReader reader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
String line = null;
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
reader.close();
} catch (final Exception e) {
e.printStackTrace();
}
}
}
public void extractTarball(final File workingDir, final String archiveName)
throws Exception {
final String gzFileName = archiveName + ".tar.gz";
final String tarFileName = archiveName + ".tar";
final ProcessBuilder builder = new ProcessBuilder();
builder.redirectErrorStream(true);
builder.directory(workingDir);
builder.command("gunzip", gzFileName);
final Process unzipProcess = builder.start();
new Thread(new StreamGobbler(unzipProcess)).start();
if (unzipProcess.waitFor() == 0) {
System.out.println("Unzip complete, now untarring");
builder.command("tar", "xvf", tarFileName);
final Process untarProcess = builder.start();
new Thread(new StreamGobbler(untarProcess)).start();
System.out.println("Finished untar process. Exit status "
+ untarProcess.waitFor());
}
}

The code below will print the output of the command executed. Check if it returns any error.
Process p = Runtime.getRuntime().exec("tar -xvf "+ fileName + ".tar");
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
String line = null;
while ((line = br.readLine()) != null) {
System.out.println(line);
}

The problem is the commands which we give is UNIX command so it wont work in windows environment. I had written a script file to overcome this problem thanks all for you help. The Runtime.getRuntime.exec() will take some time to execute the command given so after each exec() give thread.wait(3000) to complete the process and goto next thread.

How do I run multiple commands in SSH through Java?

How do I run multiple commands in SSH using Java runtime?
the command: ssh user#127.0.0.1 'export MYVAR=this/dir/is/cool; /run/my/script
/myscript; echo $MYVAR'
#Test
public void testSSHcmd() throws Exception
{
StringBuilder cmd = new StringBuilder();
cmd.append("ssh ");
cmd.append("user#127.0.0.1 ");
cmd.append("'export ");
cmd.append("MYVAR=this/dir/is/cool; ");
cmd.append("/run/my/script/myScript; ");
cmd.append("echo $MYVAR'");
Process p = Runtime.getRuntime().exec(cmd.toString());
}
The command by its self will work but when trying to execute from java run-time it does not. Any suggestions or advice?

Use the newer ProcessBuilder class instead of Runtime.exec. You can construct one by specifying the program and its list of arguments as shown in my code below. You don't need to use single-quotes around the command. You should also read the stdout and stderr streams and waitFor for the process to finish.
ProcessBuilder pb = new ProcessBuilder("ssh",
"user#127.0.0.1",
"export MYVAR=this/dir/is/cool; /run/my/script/myScript; echo $MYVAR");
pb.redirectErrorStream(); //redirect stderr to stdout
Process process = pb.start();
InputStream inputStream = process.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
String line = null;
while((line = reader.readLine())!= null) {
System.out.println(line);
}
process.waitFor();

If the Process just hangs I suspect that /run/my/script/myScript outputs something to stderr. You need to handle that output aswell as stdout:
public static void main(String[] args) throws Exception {
String[] cmd = {"ssh", "root#localhost", "'ls asd; ls'" };
final Process p = Runtime.getRuntime().exec(cmd);
// ignore all errors (print to std err)
new Thread() {
#Override
public void run() {
try {
BufferedReader err = new BufferedReader(
new InputStreamReader(p.getErrorStream()));
String in;
while((in = err.readLine()) != null)
System.err.println(in);
err.close();
} catch (IOException e) {}
}
}.start();
// handle std out
InputStreamReader isr = new InputStreamReader(p.getInputStream());
BufferedReader reader = new BufferedReader(isr);
StringBuilder ret = new StringBuilder();
char[] data = new char[1024];
int read;
while ((read = reader.read(data)) != -1)
ret.append(data, 0, read);
reader.close();
// wait for the exit code
int exitCode = p.waitFor();
}

The veriant of Runtime.exec you are calling splits the command string into several tokens which are then passed to ssh. What you need is one of the variants where you can provide a string array. Put the complete remote part into one argument while stripping the outer quotes. Example
Runtime.exec(new String[]{
"ssh",
"user#127.0.0.1",
"export MYVAR=this/dir/is/cool; /run/my/script/myScript; echo $MYVAR"
});
That's it.

You might want to take a look at the JSch library. It allows you to do all sorts of SSH things with remote hosts including executing commands and scripts.
They have examples listed here: http://www.jcraft.com/jsch/examples/

Here is the right way to do it:
Runtime rt=Runtime.getRuntime();
rt.exec("cmd.exe /c start <full path>");
For example:
Runtime rt=Runtime.getRuntime();
rt.exec("cmd.exe /c start C:/aa.txt");

If you are using SSHJ from https://github.com/shikhar/sshj/
public static void main(String[] args) throws IOException {
final SSHClient ssh = new SSHClient();
ssh.loadKnownHosts();
ssh.connect("10.x.x.x");
try {
//ssh.authPublickey(System.getProperty("root"));
ssh.authPassword("user", "xxxx");
final Session session = ssh.startSession();
try {
final Command cmd = session.exec("cd /backup; ls; ./backup.sh");
System.out.println(IOUtils.readFully(cmd.getInputStream()).toString());
cmd.join(5, TimeUnit.SECONDS);
System.out.println("\n** exit status: " + cmd.getExitStatus());
} finally {
session.close();
}
} finally {
ssh.disconnect();
}
}