2015 FRQ Issue - Shaurya Goel

[STG-7]

FRQ 1 (FRQ 1 (1D & 2D Arraylists)

FRQ 1 Link

Association

Sending a Message in ChatApiController.java

In the sendMessage method, a new Chat object is created and saved using ChatJpaRepository. This method is a POST mapping that expects parameters for email, message, fromEmail, personId, and fromPersonId.

@PostMapping("create")
public String sendMessage(@RequestParam String email, @RequestParam String message, @RequestParam String fromEmail,
        @RequestParam long personId, @RequestParam long fromPersonId) {
    Chat chat = new Chat(email, message, fromEmail, personId, fromPersonId);
    Chat savedChat = chatJpaRepository.save(chat);

    // store this message somewhere and deliver to user
    return "Message Sent Successfully. ID: " + savedChat.getId();
}

• Here, I am creating a new Chat object using the provided parameters.
• Then, I save this Chat object using the chatJpaRepository.save(chat) method.

• Finally, I return a message indicating the successful sending of the message, along with the ID of the saved Chat object.

  FRQ 2 (Classes)

  FRQ 2 Link

  Association

  Chat.java

  
  @Entity (name = "chat")
  public class Chat {
  
  public Chat() {}
  
  @Id 
  @Column(name = "id")
  @GeneratedValue(strategy = GenerationType.AUTO)
  private Long id;
  
  @NotNull
  @Column(name = "message")
  private String message;
  
  @NotNull
  @Column(name = "email")
  private String email;
  
  @NotNull
  @Column(name = "person_id")
  private Long personId;
  
  @NotNull
  @Column(name = "from_person_id")
  private Long fromPersonId;
  
  @NotNull
  @Column(name = "from_email")
  private String fromEmail;
  
  @NotNull
  @Column(name = "read_flag")
  private boolean readFlag = false;
  
  @Column(name = "date_sent")
  private Date dateSent;
  
  @Column(name = "date_read")
  private Date dateRead;
  
  /*@ManyToOne
  @JoinColumn(name = "id")
  private Person person;*/
  
  public Chat (String email, String message, String fromEmail, long personId, long fromPersonId){
      this.email = email;
      this.message = message;
      this.fromEmail = fromEmail;
      this.readFlag = false;
      this.personId = personId;
      this.fromPersonId = fromPersonId;
      this.dateSent = new Date(System.currentTimeMillis());
  }
  
  public Long getId() {
      return id;
  }
  
  public Long getPersonId() {
      return personId;
  }
  
  public Long getFromPersonId() {
      return fromPersonId;
  }
  
  public String getMessage() {
      return message;
  }
  
  public String getEmail() {
      return email;
  }
  
  public String getFromEmail() {
      return fromEmail;
  }
  
  public boolean isReadFlag(){
      return readFlag;
  }
  
  public void setReadFlag(boolean readFlag) {
      this.readFlag = readFlag;
  }
  public Date getDateSent() {
      return dateSent;
  }
  
  public void setDateSent(Date dateSent) {
      this.dateSent = dateSent;
  }
  
  public Date getDateRead() {
      return dateRead;
  }
  
  public void setDateRead(Date dateRead) {
      this.dateRead = dateRead;
  }

}

- The Chat class represents an individual chat message in the system.
- Instances of Chat objects are created when new messages are sent, with each instance representing a single chat message.
- The class provides methods to access and modify attributes of Chat objects, such as getting the message content, email addresses, read status, and dates.
# FRQ 3 (Arrays)
### [FRQ 3 Link](https://stg-7.github.io/CSABlogging//2024/02/22/2015FRQ3_IPYNB_2_.html)
## Association
### Reading Message History in ChatApiController.java
In the readAllMessages method, I retrieve all chat messages between two specific email addresses and return them as a JSON array.

@GetMapping("history") public String readAllMessages(@RequestParam String email, @RequestParam String fromEmail) throws JsonProcessingException { List histMessages = chatJpaRepository.findByEmailAndFromEmailOrFromEmailAndEmailOrderByDateSent(email, fromEmail);

ObjectMapper objectMapper = new ObjectMapper();
String json = objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(histMessages);

// store this message somewhere and deliver to user
return json;

}

- Here, I use chatJpaRepository.findByEmailAndFromEmailOrFromEmailAndEmailOrderByDateSent to fetch all messages between the specified email and fromEmail.
- The retrieved list of Chat objects is then converted to a JSON string using ObjectMapper, and returned to the user.
# FRQ 4 (Interfaces)
### [FRQ 4 Link](https://stg-7.github.io/CSABlogging//2024/02/22/2015FRQ4_IPYNB_2_.html)
## Association
### findByEmail in ChatJpaRepository.java

List findByEmail(String email);

This method returns a List<Chat> of all chat messages where the email matches the provided parameter. The returned list acts as a 1D array of Chat objects containing messages for a specific email.
### findByEmailAndFromEmailAndReadFlagOrderByDateSent

List findByEmailAndFromEmailAndReadFlagOrderByDateSent(String email, String fromEmail, boolean readFlag);

- Similar to the previous method, this returns a List<Chat> of unread messages between two emails, sorted by date sent. Again, the returned list serves as a 1D array of Chat objects.

[rohinsood]

FRQ 1:

Code (.95/1)

• Well-Organized Code: The code is structured logically for readability and maintainability.
• Modular Approach: The use of functions like arraySum, rowSums, and isDiverse promotes code organization and reuse.
• User-Friendly Input: Inclusion of a Scanner for 2D array input enhances user experience. The displayed input grid adds clarity.

  Associations (.90/1)

  • Your method displays how the API requests can return data of variable length

FRQ 2:

Code (.95/1)

• Clear Class Structure: Neatly encapsulates hidden word and hint generation in the HiddenWord class.
• Robust Input Handling: Ensures user provides a guess of the same length as the hidden word, offering informative feedback.
• Informative Comments: Well-documented with comments explaining each method and section for enhanced readability and reference.

  Associations (.90/1)

• Your code displays how getters and setters via annotations create the blueprints of a class
• The usage of this code in your project shows your strong understanding of java topics surrounding object oriented programming languages

FRQ 3:

Code (.95/1.0)

• User-Friendly Interaction: The implementation guides users through inputting sparse array dimensions, values, and performing operations like retrieving values and removing columns.
• Logical Entry Handling: The addEntry method logically handles sparse array entries, ensuring that zero values are not added, and it dynamically updates numRows and numCols based on the entries.
• Readability: The code structure is clear and easy to follow, with concise methods like getValueAt and removeColumn. Meaningful variable names enhance overall code readability.

  Associations (.90/1.0)

• Storing data within a json object displays how iterable objects can be used

FRQ 4:

Code (.95/1.0)

• Clear Interface Design: The NumberGroup interface's single method simplifies representation and implementation.
• Effective Range Class: Range class efficiently represents integer ranges with a concise constructor and contains method.
• Efficient Collection Handling: MultipleGroups class adeptly manages a collection of NumberGroup objects, accurately checking number containment.

  Associations (.90/1.0)

• Those methods, without implementations, shows how you understand and can relate the abstractedness of interfaces and how they must be implemented on a different layer of run time