Develop Reference

How to open IE from a java program

Hey I tried to open IE from a java program.
the command start iexplorer works on command prompt and terminal but when used in a java program throws a IOException. When I execute the command cmd start iexplorer the program is just running without stopping for almost 15 minutes
String command = "cmd start iexplore";
try {
Process p = Runtime.getRuntime().exec(command);
p.waitFor();
} catch (IOException e) {
e.printStackTrace();
} catch (InterruptedException e) {
e.printStackTrace();
}
This is the call stack of from VScode:
image
can someone help me with this please

All you are doing is running "cmd" in background. If iexplore is on your system Path then this may work:
String[] cmd = new String[] {"cmd", "/c", "start iexplore"};
The "/c" option tells CMD.EXE to start the process, and then CMD exits immediately [in your case it is hanging around for more input]. Also you need to read the STDERR stream of the process to see any error messages from CMD.

Execute a shell command line in Java

I tried to execute a shell command in Java, but it's not working.
I can directly run this command on Linux(Ubuntu):
/bin/sh -c 'while true ; do java -jar /home/user/workspace/TCPClientNew/WebContent/NewClient.jar 192.168.138.1 6789 ; sleep 1 ; done'
but when I do this with Java, it never executes. It always shows "Not Found".
Here is my code:
Runtime rt = Runtime.getRuntime();
Process proc;
String[] commands = {"/bin/sh","-c","'while true ; do java -jar /home/user/workspace/TCPClientNew/WebContent/NewClient.jar "+" "+host+" "+port+ " ; sleep 1 ; done'"};
proc = rt.exec(command);
Can someone tell me why it's wrong?
Thank you very much.

The single quotes in the command line are there to prevent interpretation of the third argument by the shell that runs the command line. They are not needed in Java, as there's no command line shell anymore. Just remove the single quotes.

Try to use this code might helps you.
try {
ProcessBuilder pb = new ProcessBuilder("/usr/bin/bash", "-c", "while true ; do java -jar /home/user/workspace/TCPClientNew/WebContent/NewClient.jar"+" "+host+" "+port+ " ; sleep 1 ; done");
pb.start();
} finally {
// pb.close();
}

How to backup a mysql db from java using runtime/process classes?

I have a problem with this code:
try {
String cmd = "C:\\Program Files\\MySQL\\MySQL Server 5.5\\bin\\mysqldump.exe -uroot -proot foo_db -rC:\\backup.sql";
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(cmd);
} catch(Exception e) {}
It doesn't get any error, pratically it doesn't DO anything: no backup and no execution of the cmd. Where's the problem?
It's strange, because the cmd-text is correct... i've tried to do it with 'Execute' command in windows and it works, but in java no.
Thanks in advance.

Your first problem was, as #pcalcao pointed out, that you are not reporting the exception. You really should never do this. At the very least you should do:
} catch(Exception e) {
e.printStackTrace();
}
java.io.IOException: Cannot run program "C:\Program": CreateProcess error=193, %1 isn't a Win32 valid application
That says that you have a problem with your application path. By default, if exec() is called with a single argument, then it will break the arguments up by spaces. Since you have spaces in your path you need to pass an array of strings to exec(). Something like:
try {
String cmd =
"C:\\Program Files\\MySQL\\MySQL Server 5.5\\bin\\mysqldump.exe";
Runtime rt = Runtime.getRuntime();
Process proc = rt.exec(new String[] { cmd, "-uroot", "-proot", "foo_db",
"-rC:\\backup.sql" });
// wait for it to finish
proc.waitFor();
} catch(Exception e) {
e.printStackTrace();
}
The first argument in the string array passed to exec() is then the full path to the command -- this can have spaces. Each of the other array elements is an argument to the command.
Lastly, you will need to wait for the process to finish otherwise it will execute in the background. That's what the waitFor() does.

You need to escape the whitespace with \, exec is trying to execute "C:\Program", from what you've showed in your answer to my previous comment.
NEVER leave a catch clause empty.

Execute Unix system command from JAVA problem

I am facing a weird issue with executing a system command from JAVA code.
Actually i want to get the Mac OSX system information from my JAVA App.
For that im using
Runtime.getRuntime().exec("system_profiler -detailLevel full");
This is working fine.If i print the output,it is cool.
But i want to write this information to a plist file for future use.For that im using the -xml argument of system_profiler.like,
String cmd = "system_profiler -detailLevel full -xml > "+System.getProperty( "user.home" )+"/sysinfo.plist";
Process p = Runtime.getRuntime().exec(cmd);
Basically this should create a plist file in the current users home directory.
But this seems to be not writing anything to file.
Am i missing something here ?

My Java is more than rusty, so please be gentle. ;-)
Runtime.exec() does not automatically use the shell to execute the command you passed, so the IO redirection is not doing anything.
If you just use:
"/bin/sh -c system_profiler -detailLevel full > path/file.plist"
Then the string will be tokenized into:
{ "/bin/sh", "-c", "system_profiler", "-detailLevel", "full", ">", "path/file.plist" }
Which also wouldn't work, because -c only expects a single argument.
Try this instead:
String[] cmd = { "/bin/sh", "-c", "system_profiler -detailLevel full > path/file.plist" };
Process p = Runtime.getRuntime.exec(cmd);
Of course, you could also just read the output of your Process instance using Process.getInputStream() and write that into the file you want; thus skip the shell, IO redirection, etc. altogether.

Christian.K is absolutely correct. Here is a complete example:
public class Hello {
static public void main (String[] args) {
try {
String[] cmds = {
"/bin/sh", "-c", "ls -l *.java | tee tmp.out"};
Process p = Runtime.getRuntime().exec (cmds);
p.waitFor ();
System.out.println ("Done.");
}
catch (Exception e) {
System.out.println ("Err: " + e.getMessage());
}
}
}
If you weren't using a pipe (|) or redirect (>), then you'd be OK with String cmd = "ls -l *.java", as in your original command.
If you actually wanted to see any of the output in your Java console window, then you'd ALSO need to call Process.getInputStream().
Here's a good link:
Running system commands in Java applications

How can I call a shell script from a Java program?

I use ubuntu 10.04 with eclipse. I created a shell script, exam.sh:
#!/bin/bash
echo "Hello World"
with chmod 755 exam.sh
On the command line, I can execute ./exam.sh // ok command showing me Hello World
I want to call this exam.sh with java code, this is my java code:
public static void main(String[] args) {
Runtime r = Runtime.getRuntime();
Process p = null;
String cmd[] = {"/bin/bash","cd","/home/erdi/Desktop", ".","/","exam.sh"};
try {
p = r.exec(cmd);
System.out.println("testing...");//ok
} catch (Exception e) {
e.printStackTrace();
}
}
This doesn't function, where did I make a mistake?
Yes I know i can search by google but I didn't find an answer to my problem. It gives howTos and tutorials about this feature but I didn't find an answer.

Try this instead:
cmd[] = {"/bin/bash", "/home/ercan/Desktop/exam.sh"};
You can just invoke bash on the shell script directly. To run a command string (like cd) you would need to use the -c switch.
If you need the working directory of the script to be your Desktop, you can use another overload of Runtime.exec:
Process proc = Runtime.getRuntime().exec(cmd, new String[0], new File("/home/ercan/Desktop"));
Alternatively, the ProcessBuilder class makes executing processes a bit nicer.