Files

Files
# Files Utils

>Hint: You can use the File class from the standard Java library for the implementation of the utils below (https://www.geeksforgeeks.org/file-class-in-java/).

## 1. Directory Traversal

Write a recursive method `void traverseDirectories(String path)` which prints the names of all files in the given `path`

### Example usage

```java
String path = Paths.get("demo").toAbsolutePath().toString();
FilesUtils.traverseDirectories(path);
```

### Expected output

```
demo:
  nested-1:
    file-1.md
    file-2.md
    file-3.md
    nested-1-1:
      example.txt
  nested-2:
    test-1.csv
    test-2.txt
    test-3.md
```

## 2. Find Files

Write method `List<String> findFiles(String path, String extension)` which return a collection of all files which have the given `extension` in the given directory.

### Example usage

```java
String path = Paths.get("demo").toAbsolutePath().toString();
System.out.println(findFiles(path, "md"));
```

### Expected output

```
[file-1.md, file-2.md, file-3.md, test-3.md]
```

### 3. File Exists

Write a recursive method `boolean fileExists(String path, String fileName)`

### Example usage

```java
String path = Paths.get("demo").toAbsolutePath().toString();
System.out.println(fileExists(path, "test-3.md"));
System.out.println(fileExists(path, "test-2.md"));
```

### Expected Output

```
true
false
```

### 4. Directory Stats

Write a recursive method `Map<String, Integer> getDirectoryStats(String path)` which returns the number of files for each file extension.

### Example usage

```java
String path = Paths.get("demo").toAbsolutePath().toString();
System.out.println(FilesUtils.getDirectoryStats(path));
```

### Expected Output

```
{txt=2, md=4, csv=1}
```


public class FilesUtils {

    public static Map<String, Integer> directoryStats = new HashMap<>();

    public static void traverseDirectories(String path) {
        File dir = new File(path);
        File[] allFiles = dir.listFiles();
        if (allFiles == null) {
            return;
        }
        if (allFiles.length == 0) {
            return;
        }
        System.out.println(dir.getName() + ":");

        String indent = "";
        traverseRecursive(allFiles, indent);
    }

    private static void traverseRecursive(File[] list, String indent) {
        if (list == null) return;
        if (list.length == 0) return;
        indent += " ";
        for (File file : list) {
            if (file.isDirectory()) {
                System.out.println(indent + file.getName() + ":");
                traverseRecursive(file.listFiles(), indent);
            }
            if (file.isFile()) {
                System.out.println(indent + file.getName());
            }
        }
    }

    public static List<String> findFiles(String path, String extension) {
        File fileSearch = new File(path);
        File[] allFiles = fileSearch.listFiles();
        List<String> result = new ArrayList<>();
        if (allFiles == null) {
            return result;
        }
        if (allFiles.length == 0) {
            return result;
        }
        for (File file : allFiles) {
            if (file.isDirectory()) {
                result.addAll(findFiles(file.toString(), extension));
            } else {
                if (file.getName().endsWith(extension)) {
                    result.add(file.getName());
                }
            }
        }
        return result;
    }

    public static boolean fileExists(String path, String fileName) {
        File dir = new File(path);
        File[] allFilesInDir = dir.listFiles();
        boolean fileNameExist = false;

        if (allFilesInDir == null || allFilesInDir.length == 0) {
            return false;
        }
        for (File file : allFilesInDir) {
            if (file.isDirectory()) {
                fileNameExist = fileExists(file.toString(), fileName);
            }
            if (file.getName().equals(fileName)) {
                return true;
            }
        }
        return fileNameExist;
    }

    public static Map<String, Integer> getDirectoryStats(String path) {
        File dir = new File(path);
        File[] allFilesInDir = dir.listFiles();
        for (File file : allFilesInDir) {
            String temp = file.getName().substring(file.getName().indexOf(".") + 1);
            if(file.isDirectory()){
                getDirectoryStats(file.toString());
        }
            if(file.isFile() && directoryStats.containsKey(temp)){
                directoryStats.replace(temp, directoryStats.get(temp) + 1);
            }
            if(file.isFile() && !directoryStats.containsKey(temp)){
                directoryStats.put(temp, 1);
            }
        }
        return directoryStats;
    }
    }