Can we call a Windows cmd command in Java? For example, calling the "unzip" command of Windows in a Java program. Would that be difficult?
Yes, that's possible. The most basic API which Java SE provides for this is the Runtime#exec(). It has some known traps though, this article is an excellent read: When Runtime.exec() won't.
Note that Java SE provides the java.util.zip package as well for zipping/unzipping files programmatically. See also this article for a guide.
yes you can do it,USE
**Runtime.getRuntime().exec("your command");**
I would suggest using the newer class ProcessBuilder: http://download.oracle.com/javase/6/docs/api/java/lang/ProcessBuilder.html
It holds your hand a little bit more and it allows you to merge the error and stdout streams so that you don't have to have two streamgobbler threads running.
Related
I want to use Linux grep in my java program for searching, because grep's performance is satisfying. But I don't want to call it with Runtime.getRuntime().exec() command from operating system. Therefore I downloaded grep-2.9 source code but now I don't know how I can integrate that code to my java app. Is there any way to use grep or other linux commands directly, not from OS?
I think you should better try this:Grep4J
Another possible alternative is to use groovy they have grep supported by the language library
Both of approaches are better then running linux specific utilities from Java.
Hope this helps
I have poker bot written in C++. I want to compete it with another Poker Academy agent. In order to do that there is an API in JAVA namely "meerkat api".
I have no idea how to call my c++ executable from java api, how does one go about communicating with the independent c++ executable from within a java package?
To get started see:
java.lang.Runtime.exec() family
java.lang.ProcessBuilder
Or if you need to integrate with the C++ app on lower lvl meaning not only "run a program and process the results". You can use the JNI or easier variant JNA, but I have to admit it is pain.
After reading/following #hmjd, Well you can use DefaultExecutor from Apache Commons Exec library to execute commands but it internally uses java.lang.Runtime and java.lang.Process.
I would suggest you to use this library over Runtime because Apache Command Execution APIs are more sophisticated, and provide all and more features than Java Runtime. It also handles exit Values.
I have a java code and created a jar file.
I need to create an Qt application. Can I use this code in that application?
Please help me how can i use that jar file.
Thanks,
Nagaraju.
You could take a look at the capabilities of GCC/GCJ (see http://gcc.gnu.org/ ). IF it's a good idea is a whole other story, and depends on what you have, and what you're trying to accomplish. It should be doable to link SO's created with GCJ in QT applications, but I seriously wonder if you are not better off using either C++ or Java, but not mixing them
If your Java code takes input from stdin or some file and writes output to stdout or some file, then the easiest way is to fork java to run that jar, and parse the output in your Qt code.
Things other than that, you'll need to be a bit specific. Something like "my Java code does painting the screen".
My advice is to use SWT or Swing.
You can use gcj gcj to compile the java code to library and simply call the functions of the java code from your C code.
Yes, you can use your jar file in your Qt application. I've done exactly this myself.
One way is to use the JNI Invocation API. This is part of the Java Native Interface (JNI), which makes it feasible but not pleasant to access Java APIs from C++.
A much more pleasant approach is to use CodeMesh JunC++ion, which wraps the Java APIs in C++ classes. This is a great product, if you can afford it.
If you have very little Java code, it may be easier to port it to C++.
can a java application call a unix executable written in c++? basically i have written code in unix in c++ and shared the executable with a couple of companies. All is well save for this on e company that is using java under a linx platform. would it not be possible for them to just call my executable from their java app? of course i make sure my unix os matches their etc etc. but i don't want to redevelop my code using java for this. any solution to this problem?
Yes, it's possible. To execute a command:
String command = "./myscript";
Process process = Runtime.getRuntime().exec(command);
You can change the command to execute your C++ program.
See also here and here (the latter of which discusses Windows as well as *nix.)
Have a look at ProcessBuilder. I'm assuming your executable is a compiled command line application (and you're not out to call / integrate your C++ code from Java directly).
Java would still be using the operating system to run the native code. To run your program on Linux you need to compile a Linux binary.
Yes, you can. Take a look at the Runtime class in the Java api, you will found your answer there. But also, be aware of what J2EE Specifications are about doing these kinds of things.
Cheers.
As long as you can run the command without Java, you can use Runtime.getRuntime().exec(command); to launch it from a Java process.
is there something like API built atop the standard ProcessBuilder for calling system programs? I won't argue that scripts can be ported to Java but utilities like arping and netstat are good-to-go in Linux.
Have a look at Apache Commons Exec.
Why not just use the standard ProcessBuilder class... It handles calling scripts pretty well. Here is a post showing how this can be used to call a command via bash.
Using Runtime.getRuntime().exec(...) except you need to know the name and parameters to pass to system program.