This tutorial shows how to get the list of resources (files) from a classpath directory and subdirectory.
Examples
Example resource directory structure
D:\files-in-classpath-under-folder-and-subfolder>tree /a /f src/main/resources Folder PATH listing Volume serial number is B2F7-682A D:\FILES-IN-CLASSPATH-UNDER-FOLDER-AND-SUBFOLDER\SRC\MAIN\RESOURCES | a.txt | +---subfolder1 | b.txt | \---subfolder2 | c.txt | \---subsubfolder21 d.txt
Using plain Java
package com.logicbig.example;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;
public class FilesInClassPathJavaExample {
public static void main(String[] args) {
System.out.println("-- under subfolder2 --");
List<File> resourceFolderFiles = getResourceFolderFiles("subfolder2");
resourceFolderFiles.stream().filter(f -> f.getName().endsWith(".txt")).forEach(System.out::println);
System.out.println("-- under all folders in classpath --");
resourceFolderFiles = FilesInClassPathJavaExample.getResourceFolderFiles("");
resourceFolderFiles.stream().filter(f -> f.getName().endsWith(".txt")).forEach(System.out::println);
}
static List<File> getResourceFolderFiles(String folder) {
ClassLoader loader = Thread.currentThread().getContextClassLoader();
URL url = loader.getResource(folder);
String path = url.getPath();
File file = new File(path);
List<File> files = new ArrayList<>();
if(file.isDirectory()){
try {
Files.walk(file.toPath()).filter(Files::isRegularFile).forEach(f -> files.add(f.toFile()));
} catch (IOException e) {
throw new RuntimeException(e);
}
}else{
files.add(file);
}
return files;
}
}
-- under subfolder2 --
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\c.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\subsubfolder21\d.txt
-- under all folders in classpath --
D:\files-in-classpath-under-folder-and-subfolder\target\classes\a.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder1\b.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\c.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\subsubfolder21\d.txt
Using Spring PathMatchingResourcePatternResolver
package com.logicbig.example;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import java.io.File;
import java.io.IOException;
public class FilesInClassPathSpringExample {
public static void main(String[] args) throws IOException {
System.out.println("-- under subfolder2 --");
PathMatchingResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
Resource[] resources = resourcePatternResolver.getResources("classpath:subfolder2/**/*.txt");
for (Resource resource : resources) {
File file = resource.getFile();
System.out.println(file);
}
System.out.println("-- under all folders in classpath --");
PathMatchingResourcePatternResolver resourcePatternResolver2 = new PathMatchingResourcePatternResolver();
Resource[] resources2 = resourcePatternResolver.getResources("classpath:**/*.txt");
for (Resource resource : resources2) {
File file = resource.getFile();
System.out.println(file);
}
}
}
-- under subfolder2 --
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\c.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\subsubfolder21\d.txt
-- under all folders in classpath --
D:\files-in-classpath-under-folder-and-subfolder\target\classes\a.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder1\b.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\c.txt
D:\files-in-classpath-under-folder-and-subfolder\target\classes\subfolder2\subsubfolder21\d.txt
