List Files from Templates Directory in Spring Boot - spring

Question

I would like to generate a blog posts overview. For that I want to read the html files from a folder inside the templates folder in the resources folder where Spring Boot stores its templates.
I tried that but it doesnt return an error but also list no files.
What is the way to go here?
Thanks
#Controller
public class Route {
#Autowired
private ResourceLoader resourceLoader;
#RequestMapping("/")
public String home() throws IOException {
final String path = "templates/blog";
final Resource res = resourceLoader.getResource("templates/blog");
try (final BufferedReader reader = new BufferedReader(new InputStreamReader(res.getInputStream()))) {
reader.lines().forEachOrdered(System.out::println);
}
return "blog/a";
}
}

Answer 1

#Controller
public class Route {
#Value("classpath:templates/blog/*")
private Resource[] resources;
#RequestMapping("/")
public String home() throws IOException {
for (final Resource res : resources) {
System.out.println(res.getFilename());
}
return "blog/a";
}
}
did the trick to me.

Answer 2

You should be able to achieve this using NIO2.
In order for NIO2 to work, it requires the concept of FileSystem, and one can be created from the jar URI. Then this file system can be used with Files/Paths.
The code below contains two branches - the first handles loading the files from inside Jar, the second branch - when the code runs from IDE or via "mvn spring-boot:run".
All streams are being used via try-with-resources so they will be auto-closed.
The find function starts from the top of the file system and recursively searches for html files.
public static void readFile(String location) throws URISyntaxException {
URI uri = Objects.requireNonNull(ReadFromJar.class.getClassLoader().getResource(location)).toURI();
if (uri.getScheme().equals("jar")) { //inside jar
try (FileSystem fs = FileSystems.newFileSystem(uri, Collections.emptyMap())) { //build a new FS that represents the jar's contents
Files.find(fs.getPath("/"), 10, (path, fileAttr) -> // control the search depth (e.g. 10)
fileAttr.isRegularFile() //match only files
&& path.toString().contains("blog") //match only files in paths containing "blog"
&& path.getFileName().toString().matches(".*\\.html")) // match only html files
.forEach(ReadFromJar::printFileContent);
} catch (IOException ex) {
ex.printStackTrace();
}
}
else { //from IDE or spring-boot:run
final Path path = Paths.get(uri);
try (DirectoryStream<Path> dirStream = Files.newDirectoryStream(path)) {
dirStream.forEach(ReadFromJar::printFileContent);
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void printFileContent(final Path file) {
try {
System.out.println("Full path: " + file.toAbsolutePath().toString());
Files.lines(file).forEach(System.out::println);
} catch (IOException e) {
e.printStackTrace();
}
}