Compile a .java File Programmatically

Question

I want to create a program that can Compile a .java file to a .class file like it is done on this website: Innovation website

My questions are:

Is there an library i can use to do this?
Where can I get this Library?
If there isn't a library for this then how can i do this?

It is compiling the files. You have to get the files and pass them as arguments to the jdk. I don't think there is a library to do this. This is very straight forward once you know how java works. — luanjot, Jan 11 '15 at 13:10
possible duplicate of [How to run Java program in command prompt](http://stackoverflow.com/questions/11965818/how-to-run-java-program-in-command-prompt) — Coding Enthusiast, Jan 11 '15 at 13:25

score 5 · Answer 1 · answered Jan 11 '15 at 13:14

   JavaCompiler javac = ToolProvider.getSystemJavaCompiler();

The javadoc for JavaCompiler shows how to work and compile with this JDK facility. One snippet from there:

   File[] files1 = ... ; // input for first compilation task

   JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
   StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);

   Iterable<? extends JavaFileObject> compilationUnits1 =
       fileManager.getJavaFileObjectsFromFiles(Arrays.asList(files1));
   compiler.getTask(null, fileManager, null, null, null, compilationUnits1).call();

It is by no means a simple task. But a general method for invoking a Java compiler via the shell - with all the trimmings - isn't easy either, and this, then, also applies to calls via Process.

score 2 · Accepted Answer · edited Jan 11 '15 at 15:13

2

You can do this using the Process class as

Process pro=Runtime.getRuntime().exec("javac FileName.java", null, new File("\path"));

edited Jan 11 '15 at 15:13

Zach Saucier

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answered Jan 11 '15 at 14:08

Abhi

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The /path is the output file path right? – Fryslan Jan 11 '15 at 16:10
No its input file FileName.java path, output file will be generated at the same location – Abhi Jan 11 '15 at 16:15
O right is there an way to move the files to another directory using the process? – Fryslan Jan 11 '15 at 16:23
Nvm I just had to add -d /outputPath to the process – Fryslan Jan 11 '15 at 16:29
Ya exactly! -d to generate it to specific directory – Abhi Jan 11 '15 at 16:53

score 0 · Answer 3 · answered Jan 11 '15 at 13:20

0

use ProcessBuilder to execute system commands.

Install JDK and form command "javac JavaFileName" pass this to ProcessBuilder constructor and call method start()

answered Jan 11 '15 at 13:20

Saravana

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We have seen this often enough in the referenced duplicates. – laune Jan 11 '15 at 13:23

Compile a .java File Programmatically

3 Answers3