How to get all files with xml extension placed in resources of springboot application?

Question

I have a spring-boot application and I want to collect all XML files which are placed in the /src/main/resources directory which follows a structure as given below:

-resources
   -files
      -dir1
        -dir11
           a.xml
           b.xml
      -dir2
        -dir21
          c.xml
      -dir3
        -dir31
          d.xml 

I have tried few solutions like using ResourceUtils.getFile , ClassPathResource , ResourcePatternResolver , ClassLoader but these only work when I am running my application in IDE and dont work if I package my application as jar and deploy it. I get below exception

java.io.FileNotFoundException: class path resource [files] cannot be resolved to absolute file path because it does not reside in the file system:

Directory names (dir1, dir11, dir2 etc) and file names (a.xml, b.xml) are not fixed and so not known in code.

These directories and files can have any names.

resources/files is the only known directory and I want to collect all xml files inside this directory and its subdirectory.

I have tried almost all solutions found on net, but nothing seems to work for my use-case.

How can this be done? Thanks in advance.

Answer 1

Edit

You can fetch the known directory files and recursively list all the File[] objects.

It would be easier if you user org.apache.commons.io.FileUtils.listFiles(File directory, String[] extensions, boolean recursive);

I've created a helper function like below to wrap the logic of String.format and classpath:

public static File getResourceAsFile(String relativeFilePath) throws FileNotFoundException {
        return ResourceUtils.getFile(String.format("classpath:%s",relativeFilePath));

}

And to use it,

String relativeFilePath ="files";

File file =getResourceAsFile(relativeFilePath);


Collection<File> files=FileUtils.listFiles(file,null,true); //

And if you want to read all the xml files, then pass second parameter as

Collection<File> files=FileUtils.listFiles(file,new String[]{"xml"},true);