Notes

Sure, here is a basic implementation of the application you described:

```
import java.io.File;
import java.util.Scanner;

public class FileManager {
public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);
int choice = 0;
do {
// Display menu
System.out.println("***** File Manager Menu *****");
System.out.println("1. Insert file name");
System.out.println("2. Display all file names");
System.out.println("3. Delete all files");
System.out.println("0. Exit");

// Get user input
System.out.print("Enter choice: ");
choice = scanner.nextInt();

switch(choice) {
case 1:
System.out.print("Enter file name: ");
String fileName = scanner.next();
createFile(fileName);
break;
case 2:
displayAllFiles();
break;
case 3:
deleteAllFiles();
break;
case 0:
System.out.println("Exiting...");
break;
default:
System.out.println("Invalid choice!");
}

} while(choice != 0);

scanner.close();
}

public static void createFile(String fileName) {
File file = new File(fileName);
try {
if(file.createNewFile()) {
System.out.println("File created: " + file.getName());
} else {
System.out.println("File already exists!");
}
} catch(Exception e) {
System.out.println("Error creating file: " + e.getMessage());
}
}

public static void displayAllFiles() {
File folder = new File(".");
File[] fileList = folder.listFiles();
System.out.println("All files in current directory: ");
for(File file: fileList) {
System.out.println(file.getName());
}
}

public static void deleteAllFiles() {
File folder = new File(".");
File[] fileList = folder.listFiles();
for(File file: fileList) {
if(file.delete()) {
System.out.println("Deleted file: " + file.getName());
} else {
System.out.println("Failed to delete file: " + file.getName());
}
}
}
}
```

Explanation:
- `main` method: This is the main method which displays the menu and calls the relevant methods based on the user's choice. It uses a `do-while` loop to repeatedly display the menu until the user chooses to exit.
- `createFile` method: This method takes a file name as input and creates a file with that name. It uses the `File` class to create the file.
- `displayAllFiles` method: This method gets all the files in the current directory using the `listFiles` method of the `File` class and displays their names.
- `deleteAllFiles` method: This method gets all the files in the current directory using the `listFiles` method of the `File` class and deletes them.

Note: In this implementation, the file operations are performed on the current directory. You can modify the code to use a specific directory if needed. Also, this implementation does not handle exceptions such as invalid file names, permission errors, etc. You can add relevant error handling code as per your requirements.