Question

Activity: Writing Classes Page 1 of 10 Terminology attribute / state behavior class method header class header instance variable UML class diagram encapsulation client visibility (or access) modifier accessor method mutator method calling method method declaration method invocation return statement parameters constructor Goals By the end of this activity you should be able to do the following: > Create a class with methods that accept parameters and return a value Understand the constructor and the toString method of a class ► Create a class with main that uses the class created above ► Create a jGRASP project containing all of the classes for your program Generate a UML class diagram and documentation > Create a jGRASP canvas for your program and run the program in the canvas Description In this activity, you will create two classes: one called User Info and another called User InfoDriver which contains a main method that uses the first class (i.c., UserInfoDriver creates instances of UserInfo and calls its methods). You will also create a project, UML class diagram, and canvas for the program Part 1: User Info.java - Create and test the User Info class. Create your Userinfo class and add the following comments (there will be no main method in this class). Save this class in a file named Userinfo.java as soon as you have entered the code below. Don't forget to add your Javadoc comments, the constructor and each method will need one 3 public class User Info 17 instance variables // constructor Il methods Instance variables (or fields) represent the information that an object of the class needs to store. Declare the following variables after the comment: // instance variables O firstName: a String for the user's first name o lastName: a String for the user's last name o location: a String for the user's location age: an int for the user's age status: int indicates whether the user is online or offline Hint: Use the private access modifier so that values cannot be directly accessed from outside of the object, for example, declare firstName as follows: private String first Name: Constants store values that cannot be changed. Use constants to represent the two possible statuses of the user. Constants are usually grouped with the instance variables. Page 1 of 10

Answer 1

UserInfo. java
-----------------------

public class UserInfo {
  
   private String firstName;
   private String lastName;
   private String location= "Not specified";
   private int age=0;
   private static final int OFFLINE =0, ONLINE=1;
   private int status = OFFLINE;
  

   public UserInfo(String firstNameIn, String lastNameIn) {
       super();
       firstName = firstNameIn;
       lastName = lastNameIn;
   }

   @Override
   public String toString() {
       String output= " firstName : " + firstName + "\n lastName : " + lastName + "\n location : " + location + "\n age : " + age
               + "\n status : " + status;
       if(status==OFFLINE){
           output+= "offline";
       }
       else
       {
           output+= "online";
       }
      
       return output;
   }
  
   public boolean setAge(int ageIn){
       boolean isSet = false;
       if(ageIn>0){
           age=ageIn;
           isSet=true;
       }
      
       return isSet;
   }
  
   public int getAge(){
       return age;
   }
  
   public String getLocation(){
       return location;
   }
  
   public void logOff(){
       status=OFFLINE;
   }
  
   public void logOn(){
       status=ONLINE;
   }
  
   public void setLocation(String location) {
       this.location = location;
   }

   public static void main(String[] args) {
      
       UserInfo u = new UserInfo("Jane", "Lane");
       System.out.println(u);
      
       u.setAge(23);
       u.setLocation("Auburn");
       u.logOn();
       System.out.println(u);
      
   }

}

Problems @ Javadoc Declaration Con <terminated > UserInfo [Java Application) C:\Program firstName : Jane lastName : Lane location : Not specified age : 0 status : Ooffline firstName : Jane lastName : Lane location : Auburn age : 23 status : lonline

UserDriveInfo.java
----------------------

public class UserInfoDriver {

   public static void main(String[] args) {
       // TODO Auto-generated method stub
       UserInfo user1 = new UserInfo("Fat", "Doe");
       System.out.println("\n"+ user1);
       user1.setLocation("Aur=burn");
       user1.setAge(19);
       user1.logOn();
       System.out.println("\n"+ user1);
      
      
       UserInfo user2 = new UserInfo("Sam", "Jones");
       System.out.println("\n"+ user2);
       user2.setLocation("Aurburn");
       user2.setAge(19);
       user2.logOn();
       System.out.println("\n"+ user2);
   }

}

Problems @ Javadoc Declaration & Cons <terminated > UserInfoDriver (Java Application) C:\Pro JU firstName : Fat lastName : Doe location : Not specified age : 0 status : Ooffline firstName : Fat lastName : Doe location : Aur=burn age : 19 status : lonline firstName : Sam lastName : Jones location : Not specified age : 0 status : Ooffline firstName : Sam lastName : Jones location : Aurburn age : 19 status : lonline

The above programs are created as your instructions. I hope it helpful

Thank you.

Note: You can create UML diagrams in Eclipse IDE easily with these programs.