public class UserService {

  private UserRepository userRepository;

  public UserService(UserRepository userRepository) {
    this.userRepository = userRepository;
  }

  public User getUserById(long id) {
    try {
      return userRepository.getUserById(id);
    } catch (Exception e) {
      // Log the exception here
      System.out.println("An error occurred while fetching the user: " + e.getMessage());
      return null;
    }
  }
}

public class UserRepository {

  public User getUserById(long id) throws Exception {
    // Database query to fetch the user
    if (id < 0) {
      throw new Exception("Invalid user id");
    }
    // Return the user object
    return new User(id, "John Doe");
  }
}

public class User {

  private long id;
  private String name;

  public User(long id, String name) {
    this.id = id;
    this.name = name;
  }

  public long getId() {
    return id;
  }

  public String getName() {
    return name;
  }
}

//sample code to write 100 random ints to a file, 1 per line

import java.io.PrintStream;
import java.io.IOException;
import java.io.File;

import java.util.Random;

public class WriteToFile {
    public static void main(String[] args) {
        try {
            PrintStream writer = new PrintStream(new File("randInts.txt"));
            Random r = new Random();
            final int LIMIT = 100;

            for (int i = 0; i < LIMIT; i++) {
                writer.println(r.nextInt());
            }
            writer.close();
        } catch (IOException e) {
            System.out.println("An error occured while trying to write to the file");
        }
    }
}

import javax.mail.*;
import javax.mail.internet.*;
import java.util.*;
 
public void postMail( String recipients[ ], String subject, String message , String from) throws MessagingException
{
    boolean debug = false;
 
     //Set the host smtp address
     Properties props = new Properties();
     props.put("mail.smtp.host", "smtp.example.com");
 
    // create some properties and get the default Session
    Session session = Session.getDefaultInstance(props, null);
    session.setDebug(debug);
 
    // create a message
    Message msg = new MimeMessage(session);
 
    // set the from and to address
    InternetAddress addressFrom = new InternetAddress(from);
    msg.setFrom(addressFrom);
 
    InternetAddress[] addressTo = new InternetAddress[recipients.length]; 
    for (int i = 0; i < recipients.length; i++)
    {
        addressTo[i] = new InternetAddress(recipients[i]);
    }
    msg.setRecipients(Message.RecipientType.TO, addressTo);
    
 
    // Optional : You can also set your custom headers in the Email if you Want
    msg.addHeader("MyHeaderName", "myHeaderValue");
 
    // Setting the Subject and Content Type
    msg.setSubject(subject);
    msg.setContent(message, "text/plain");
    Transport.send(msg);
}

//Leif Messinger
//Solves wordle
//Needs a list of wordle words, newline separated and 5 characters each

import java.util.*;
import java.io.File;
import java.io.FileNotFoundException;

class WordleSolver {

	public static void printPointer(int position){
		for(int i = 0; i < position; ++i){
			System.out.print(" ");
		}
		System.out.print("^");
	}

	public static void main(String[] args) throws FileNotFoundException{
		if(args.length < 1) return;
		File dictionary = new File(args[0]);
		Scanner sc = new Scanner(dictionary);
		ArrayList<String> possibleWords = new ArrayList<String>();
		while(sc.hasNextLine()){
			possibleWords.add(sc.nextLine());
		}

		Scanner input = new Scanner(System.in);

		while(possibleWords.size() > 0){
			//Choose a word out of the possible words
			final int randomIndex = (int)(Math.random() * possibleWords.size());
			String chosenWord = possibleWords.get(randomIndex);
			possibleWords.remove(randomIndex);

			System.out.println("Is it correct?");
			for(int i = 0; i < chosenWord.length(); ++i){
				System.out.println(chosenWord);
				printPointer(i);
				System.out.println(" y/n?");
				if(input.nextLine().toLowerCase().contains("y")){
					//Filter by correct character
					for(int possibleWord = possibleWords.size() - 1; possibleWord >= 0; --possibleWord){ //Has to be backwards for removing entries, also has to be int not unsigned
						if(possibleWords.get(possibleWord).charAt(i) != chosenWord.charAt(i)){
							possibleWords.remove(possibleWord);
						}
					}
				}
			}
			System.out.println("Is it misplaced?");
			//Stores a count of every letter misplaced
			short[] misplacedCounts = new short[('z'-'a')+1]; //Praise be the garbage collector
			for(int i = 0; i < chosenWord.length(); ++i){
				System.out.println(chosenWord);
				printPointer(i);
				System.out.println(" y/n?");
				if(input.nextLine().toLowerCase().contains("y")){
					//Filter to make sure there's at least as many letters as needed
					++misplacedCounts[(chosenWord.charAt(i) - 'a') - 1];
					for(int possibleWord = possibleWords.size() - 1; possibleWord >= 0; --possibleWord){	//Has to be backwards for removing entries, also has to be int not unsigned
						int count = 0;
						for(int j = 0; j < possibleWords.get(possibleWord).length(); ++j){
							if(possibleWords.get(possibleWord).charAt(j) == chosenWord.charAt(i))
								++count;
						}
						//If there's not enough of the character that we need, then we remove that from the list of possible characters
						if(count < misplacedCounts[(chosenWord.charAt(i) - 'a') - 1]){
							possibleWords.remove(possibleWord);
						}
					}
					//Also filter out words where that letter doesn't belong there
					for(int possibleWord = possibleWords.size() - 1; possibleWord >= 0; --possibleWord){ //Has to be backwards for removing entries, also has to be int not unsigned
						if(possibleWords.get(possibleWord).charAt(i) == chosenWord.charAt(i)){
							possibleWords.remove(possibleWord);
							continue;	//Breaks the current word and moves on in the loop
						}
					}
				}
			}
		}
	}
}

public class Factorial
{
	public static void main(String[] args)
	{	final int NUM_FACTS = 100;
		for(int i = 0; i < NUM_FACTS; i++)
			System.out.println( i + "! is " + factorial(i));
	}
	
	public static int factorial(int n)
	{	int result = 1;
		for(int i = 2; i <= n; i++)
			result *= i;
		return result;
	}
}

public class Solution {
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        ListNode head = new ListNode(0);
        ListNode handler = head;
        while(l1 != null && l2 != null) {
            if (l1.val <= l2.val) {
                handler.next = l1;
                l1 = l1.next;
            } else {
                handler.next = l2;
                l2 = l2.next;
            }
            handler = handler.next;
        }
        
        if (l1 != null) {
            handler.next = l1;
        } else if (l2 != null) {
            handler.next = l2;
        }
        
        return head.next;
    }
}