File path or file location for Java - new file()

Joey picture Joey · May 1, 2013 · Viewed 98.9k times · Source

I have the following structure for my project.

In Eclipse:

myPorjectName
  src
    com.example.myproject
        a.java
    com.example.myproject.data
        b.xml

In a.java, I want to read b.xml file. How can I do that? Specifically, in a.java, I used the following code:

DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse (new File("data/b.xml"));

This code cannot find b.xml. However, if I change the path to src/com/example/myproject/data/b.xml then it works. The current location seems to be in the root of my project file.

But I see other people's examples, if b.xml and a.java are in the same folder, then we can directly use new File("b.xml"). But I try putting b.xml in the same folder of a.java rather than putting in the sub folder, but it still does not work. If this works, then in my case, I should be able to use new File("data/b.xml"), right? I really do not understand why this is not working.

Answer

AllTooSir picture AllTooSir · May 1, 2013

If it is already in the classpath and in the same package, use

URL url = getClass().getResource("b.xml");
File file = new File(url.getPath());

OR , read it as an InputStream:

InputStream input = getClass().getResourceAsStream("b.xml");

Inside a static method, you can use

InputStream in = YourClass.class.getResourceAsStream("b.xml");

If your file is not in the same package as the class you are trying to access the file from, then you have to give it relative path starting with '/'.

ex : InputStream input = getClass().getResourceAsStream
           ("/resources/somex.cfg.xml");which is in another jar resource folder