Thread: Get path of current executing class

Yall doing good today forum?

I've got a question for you.
I've been through a lot of reading and Google-ing but I haven't been able to find what I need.

The nature of this problem is not sintax, or logical. Its the lack of knowledge.

I am using a method that returns the absolute path, different from what the file object provides, because I don't know how to create a file object of an existing file (at any given path) for itself (.class) to easily gain the abbilities of getPath(), getAbsolutePath(), or getCanonicalPath().

If you've got any ideas how to do this would be wonderful.

So here is what I've been using..

	private static String parentPath(){
	    return (System.getProperty("user.dir") + "\\" + Thread.currentThread().getStackTrace()[1].getClassName() + ".class");
	}
 
	private static String javaPath(){
	    System.out.print("GENERATION: " + generation + ", JAVA PATH: " + System.getProperty("user.dir") + "\\" + Thread.currentThread().getStackTrace()[1].getClassName() + ".java".replace("\\", "\\\\")); // S.O.P. CHECKPOINT
	    return (System.getProperty("user.dir") + "\\" + Thread.currentThread().getStackTrace()[1].getClassName() + ".java".replace("\\", "\\\\"));
	}

..in order to obtain the absolute path of the current class' .java file.

The part of the code not returning what I need is

System.getProperty("user.dir").

Summarizing briefly, I've got a working program that makes two copies of itself, with random names, compiles, and executes them again. (of course I've placed some safegaurds to avoid infite looping).

The are some methods in the program that require their own .java. In order to do that, first I need to send the correct path. So what it does, it obtains it's current path and name. Obtaining its own name is a piece of cake, but obtaining is own path a different story #APieceOfDifficultCake. After obtaining path and name I parse both of them and add ".java" at the end.

System.getProperty("user.dir") seems to be returning the original path of the very first class "Earth" which is at C:\Users\Andrew\Desktop\, and continues to send that directory in the other two programs, instead of their own directory. SEE OUTPUT BELOW.

C:\Users\Andrew\Desktop>java Earth
GENERATION: 0, JAVA PATH: C:\Users\Andrew\Desktop\Earth.javaOUT: GENERATION: 1, JAVA PATH: C:\Users\Andrew\Desktop\zxrhgzu.javaERR: Error: Could not find or load main class exmwvbq
OUT: GENERATION: 1, JAVA PATH: C:\Users\Andrew\Desktop\zxrhgzu.javaERR: Error: Could not find or load main class nqylylo
ERR: java.io.FileNotFoundException: C:\Users\Andrew\Desktop\zxrhgzu.java (The system cannot find the file specified)
ERR: at java.io.FileInputStream.open(Native Method)
ERR: at java.io.FileInputStream.<init>(Unknown Source)
ERR: at java.io.FileReader.<init>(Unknown Source)
ERR: at zxrhgzu.replicate(zxrhgzu.java:64)
ERR: at zxrhgzu.create(zxrhgzu.java:52)
ERR: at zxrhgzu.newStandAlone(zxrhgzu.java:113)
ERR: at zxrhgzu.mitosis(zxrhgzu.java:118)
ERR: at zxrhgzu.main(zxrhgzu.java:131)
ERR: java.io.FileNotFoundException: C:\Users\Andrew\Desktop\zxrhgzu.java (The system cannot find the file specified)
ERR: at java.io.FileInputStream.open(Native Method)
ERR: at java.io.FileInputStream.<init>(Unknown Source)
ERR: at java.io.FileReader.<init>(Unknown Source)
ERR: at zxrhgzu.replicate(zxrhgzu.java:64)
ERR: at zxrhgzu.create(zxrhgzu.java:52)
ERR: at zxrhgzu.newStandAlone(zxrhgzu.java:113)
ERR: at zxrhgzu.mitosis(zxrhgzu.java:118)
ERR: at zxrhgzu.main(zxrhgzu.java:131)
GENERATION: 0, JAVA PATH: C:\Users\Andrew\Desktop\Earth.javaOUT: GENERATION: 1, JAVA PATH: C:\Users\Andrew\Desktop\xwnbosk.javaERR: Error: Could not find or load main class covlpvu
OUT: GENERATION: 1, JAVA PATH: C:\Users\Andrew\Desktop\xwnbosk.javaERR: Error: Could not find or load main class keazzov
ERR: java.io.FileNotFoundException: C:\Users\Andrew\Desktop\xwnbosk.java (The system cannot find the file specified)
ERR: at java.io.FileInputStream.open(Native Method)
ERR: at java.io.FileInputStream.<init>(Unknown Source)
ERR: at java.io.FileReader.<init>(Unknown Source)
ERR: at xwnbosk.replicate(xwnbosk.java:64)
ERR: at xwnbosk.create(xwnbosk.java:52)
ERR: at xwnbosk.newStandAlone(xwnbosk.java:113)
ERR: at xwnbosk.mitosis(xwnbosk.java:118)
ERR: at xwnbosk.main(xwnbosk.java:131)
ERR: java.io.FileNotFoundException: C:\Users\Andrew\Desktop\xwnbosk.java (The system cannot find the file specified)
ERR: at java.io.FileInputStream.open(Native Method)
ERR: at java.io.FileInputStream.<init>(Unknown Source)
ERR: at java.io.FileReader.<init>(Unknown Source)
ERR: at xwnbosk.replicate(xwnbosk.java:64)
ERR: at xwnbosk.create(xwnbosk.java:52)
ERR: at xwnbosk.newStandAlone(xwnbosk.java:113)
ERR: at xwnbosk.mitosis(xwnbosk.java:118)
ERR: at xwnbosk.main(xwnbosk.java:131)

If you see ie Could not find or load main class covlpvu its because when its time to compile the file, its got no code in it, ultimately because the path given to the method that accesses the java file is incorrect, thus not letting it write the java code.

I would really appreciate some feedback.

that is just very clever!

I never thought about that. I'll have to look at the substring() afterwards, it could be very useful.

I've been looking real hard but its actually much easier way than I thought.
I'll try that see how it goes.

Off Topic: By the way, there was some low leveled seismic activity 30 min ago Honduras.

--- Update ---

I've updated the code. Everything seems to be working great, except in one place.

The value returned by what you've posted persists to show the original directory of the first program.

See post #7

Keeps returning the original address.

	private static String parentPath() { return (getOwnDir() + getOwnName() + ".class"); }
 
	private static String javaPath() { return (getOwnDir() + getOwnName() + ".java"); }
 
	private static String getOwnName() { return (Thread.currentThread().getStackTrace()[1].getClassName()); }
 
	private static String getOwnDir() { 
	    File f = new File("temp");       
		String local = f.getAbsolutePath().substring(0,f.getAbsolutePath().length()-4);
		try { if(f.exists()) if(f.isFile()) f.delete(); } catch (Exception e){ e.printStackTrace(); }
		return local;
	}

No I haven't. From what I know about package I wouldn't have any need for it. Packages are just to keep collaborating class organized. This program is intended to be "Stand Alone" thus wouldn't be necessary to add a package.

I think I know a work around this problem, by having the path the program has selected to create the copies to be written in thier code passing on the paramenters without having the copies self determining their location. Prolly that'd work but I wish I could have the copies determine it themselves.

@Norm

Just for reference:

	private static String javaPath(){
	    System.out.print("GENERATION: " + generation + ", JAVA PATH: " + System.getProperty("user.dir") + "\\" + Thread.currentThread().getStackTrace()[1].getClassName() + ".java".replace("\\", "\\\\")); // S.O.P. CHECKPOINT
	    return (System.getProperty("user.dir") + "\\" + Thread.currentThread().getStackTrace()[1].getClassName() + ".java".replace("\\", "\\\\"));
	}

Ouput generated by java = javaPath(); System.out.print(java); =

C:\Users\Andrew\Desktop\Earth.java <----- This one is good
C:\Users\Andrew\Desktop\dowgpec.java <---- Not Good
C:\Users\Andrew\Desktop\sieavdh.java <---- Not Good

my original is located here: C:\Users\Andrew\Desktop\Earth.java
the other copies are created at C:\, not C:\Users\Andrew\Desktop\

Correct output should be like this:

C:\Users\Andrew\Desktop\Earth.java
C:\dowgpec.java
C:\sieavdh.java

Since the path received is not correct, I am given the following result per program :

ERR: java.io.FileNotFoundException: C:\Users\Andrew\Desktop\dowgpec.java (The system cannot find the file specified)
ERR: at java.io.FileInputStream.open(Native Method)
ERR: at java.io.FileInputStream.<init>(Unknown Source)
ERR: at java.io.FileReader.<init>(Unknown Source) <---- nothing to be read
ERR: at dowgpec.replicate(dowgpec.java:68) <---- where the method to retrieve code and return as String did not occur
ERR: at dowgpec.create(dowgpec.java:56) <---- where the writing of the code did not take place
ERR: at dowgpec.newStandAlone(dowgpec.java:122) <--- where the method that englobes the creation of a copy failed
ERR: at dowgpec.mitosis(dowgpec.java:127) <--- where the 2 copies are generated and the old class is deleted
ERR: at dowgpec.main(dowgpec.java:141) <---- where the entire program had to stop

the original one is located here: C:\Users\Andrew\Desktop\
the other three files are located C:\, regardless of their location the javaPath() method on each program continues to return C:\Users\Andrew\Desktop\ as directory for each of the programs

Why do you think the javaPath() method should return the locations of the .java files?

First, for each copy of the program, the class is created in the same directory its .java was saved on. When executing that program from the shell or cmd prompt is has its own runtime, the class should be able to obtain its own directory, the way I was trying to [ System.getProperty("user.dir") ] or the way copeg showed me. It is completely separate from the original. It should be working, but its not.

Ideally I would have each program look up its on directory, firstly because I want it to be self-sufficient, "stand alone". Secondly, I wouldn't loke to depend on more variables or lists. I am specially being persistent on it because, I wouldn't like to come to similar situation in the future and end up relying on lists! I want for the program to cut off as much information as it can from its parent program.

How were the .java files put into the folders where they are located? The code that wrote the files should save the location where it wrote them.

Like I mentioned, that's also what I've figured out. It's an easy work around, I would prefer not to use.

Buttomline I just want to figure out why the original directory is returned. Doesn't make any sense. Prolly' I am using it in a way it wasn't ment to be used, and this problem was never forseen. What I am doing is not grandiose, but it is definetly using very little of the object-oriented programming.

That's what I want. I will try that right now. (Good morning btw, I need a cup of coffee)

--- Update ---

It works. Thanks for the assistance.