Question

Hey guys! Huge part of my grade !! My code works already but I need it so it references to my node list class instead of my array, what would I need to change? My assignment  was to create a list from an assignment when we used an array, but I cant make it to work without the array, help! The professor said it was okay to either keep the array or to delete it altogether.

package zipcode;

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

public class ZipCodeDriver {

public static void main(String[] args) {
//file contening the data that will be loaded into the array
String filename = "zipcodes.txt";

// Load data
try {
Scanner infile = new Scanner(new File(filename));
ZipCodeList list = new ZipCodeList();
ZipCode c;
while(infile.hasNext()){
c = new ZipCode();
c.setZipcode(infile.nextLine());
c.setTown(infile.nextLine());
c.setState(infile.nextLine());
list.add(c);
}
infile.close();
System.out.println("Loaded " + list.getSize() + " zip codes");
  
// Search for the data
String search = "";
Scanner keyboard = new Scanner(System.in);
while(true){
System.out.print("Hello, please enter zip code to search (type done to stop): ");
search = keyboard.next();
if(search.equalsIgnoreCase("done"))
break;
c = list.find(search);
if(c == null)
System.out.println("Sorry but the zip code entered was not found");
else
System.out.println("Found " + search + ": [" + c + "]");
}
  
// In case we don''t find the data
} catch (FileNotFoundException e) {
System.out.println(e.getMessage());
}
}

}

--

package zipcode;

public class ZipCode {

//add components
private String zipcode;
private String town;
private String state;

//add constructors
public String getZipcode() {
return zipcode;
}
public void setZipcode(String zipcode) {
this.zipcode = zipcode;
}
public String getTown() {
return town;
}
public void setTown(String town) {
this.town = town;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
  
public String toString(){
return "ZipCode: " + zipcode + ", Town: " + town + ", State: " + state;
}
  
}

--

package zipcode;

public class ZipCodeList {
// Add components; The limit of the size, the array holding the data and a counter
private static int MAX_LIST_SIZE = 1000;
private ZipCode[] zipcodes;
private int count;
//counter
public ZipCodeList(){
zipcodes = new ZipCode[MAX_LIST_SIZE];
count = 0;
}
//Limit of the array
public void add(ZipCode c){
if(count == MAX_LIST_SIZE){
System.out.println("Could not add " + c);
}
else{
zipcodes[count++] = c;
}
}
//find the zipcode
public ZipCode find(String code){
for(int i = 0; i < count; i++){
if(zipcodes[i].getZipcode().equals(code))
return zipcodes[i];
}
// not found
return null;
}
  
//find size
public int getSize(){
return count;
}
}

-- And the last class which is the one I need to use on my list

public class ZipCodeListNode {
public ZipCode data;
public ZipCodeListNode next;
public ZipCodeListNode(ZipCode data, ZipCodeListNode next) {
this.data = data;
this.next = next;
}
public ZipCodeListNode(ZipCode data) {
this.data = data;
}
}
class ZipCodeList1 {
private int count;
private ZipCodeListNode head;

public ZipCodeList1() {
head = null;
count = 0;
}

public void add(ZipCode c) {
head = new ZipCodeListNode(c, head);
count++;
}

public ZipCode find(String code) {
ZipCodeListNode start = head;
while(start != null) {
if(start.data.getZipcode().equals(code)) {
return start.data;
}
start = start.next;
}

return null; // not found
}

public int getSize() {
return count;
}
}

  

Answer 1

Please find the below class modified to reference the node created. And let me know if you need further clarification on this.

ZipCodeDriver Class:

package zipcode;

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

public class ZipCodeDriver {

   public static void main(String[] args) {
       // file contening the data that will be loaded into the array
       String filename = "zipcodes.txt";
       System.out.println(filename);

       // Load data
       try {
           Scanner infile = new Scanner(new File(filename));
          
           /*Create new object myZipCodeList of type ZipCodeList1,
           * copy the Zipcode object c which was created and assigned with zipcode,town,state.
           and use the add method of class ZipCodeList1 and add ZipCode c to the ZipCodeList1 myZipCodeList.
          
           Rest of things are implemented earlier.*/
          
           ZipCodeList1 myZipCodeList = new ZipCodeList1();
           ZipCode c;
           while (infile.hasNext()) {
               c = new ZipCode();
               c.setZipcode(infile.nextLine());
               c.setTown(infile.nextLine());
               c.setState(infile.nextLine());
               myZipCodeList.add(c);
           }
           infile.close();
           System.out.println("Loaded " + myZipCodeList.getSize() + " zip codes");
          
           // Search for the data
           String search = "";
           Scanner keyboard = new Scanner(System.in);
           while (true) {
               System.out.print("Hello, please enter zip code to search (type done to stop): ");
               search = keyboard.next();
               if (search.equalsIgnoreCase("done"))
                   break;
               c = myZipCodeList.find(search);
               if (c == null)
                   System.out.println("Sorry but the zip code entered was not found");
               else
                   System.out.println("Found " + search + ": [" + c + "]");
           }

           // In case we don''t find the data
       } catch (FileNotFoundException e) {
           System.out.println(e.getMessage());
       }
   }

}

ZipCode Class:

package zipcode;

public class ZipCode {

   // add components
   private String zipcode;
   private String town;
   private String state;

   // add constructors
   public String getZipcode() {
       return zipcode;
   }

   public void setZipcode(String zipcode) {
       this.zipcode = zipcode;
   }

   public String getTown() {
       return town;
   }

   public void setTown(String town) {
       this.town = town;
   }

   public String getState() {
       return state;
   }

   public void setState(String state) {
       this.state = state;
   }

   public String toString() {
       return "ZipCode: " + zipcode + ", Town: " + town + ", State: " + state;
   }

}

ZipCodeListNode Class:

package zipcode;

public class ZipCodeListNode {
   public ZipCode data;
   public ZipCodeListNode next;

   public ZipCodeListNode() {

   }

   public ZipCodeListNode(ZipCode data) {
       this.data = data;
   }

   public ZipCodeListNode(ZipCode data, ZipCodeListNode next) {
       this.data = data;
       this.next = next;
   }

}

class ZipCodeList1 {
   private int count;
   private ZipCodeListNode head;

   public ZipCodeList1() {
       head = null;
       count = 0;
   }

   public void add(ZipCode c) {
       head = new ZipCodeListNode(c, head);
       count++;
   }

   public ZipCode find(String code) {
       ZipCodeListNode start = head;
       while (start != null) {
           if (start.data.getZipcode().equals(code)) {
               return start.data;
           }
           start = start.next;
       }

       return null; // not found
   }

   public int getSize() {
       return count;
   }
  
   public ZipCode getZipcode(){
       return this.getZipcode();
   }
  
  
}

ZipCodeList Class:

package zipcode;

public class ZipCodeList {
   // Add components; The limit of the size, the array holding the data and a
   // counter
   private static int MAX_LIST_SIZE = 1000;
   private ZipCode[] zipcodes;
   private int count;

   // counter
   public ZipCodeList() {
       zipcodes = new ZipCode[MAX_LIST_SIZE];
       count = 0;
   }

   // Limit of the array
   public void add(ZipCode c) {
       if (count == MAX_LIST_SIZE) {
           System.out.println("Could not add " + c);
       } else {
           zipcodes[count++] = c;
       }
   }

   // find the zipcode
   public ZipCode find(String code) {
       for (int i = 0; i < count; i++) {
           if (zipcodes[i].getZipcode().equals(code))
               return zipcodes[i];
       }
       // not found
       return null;
   }

   // find size
   public int getSize() {
       return count;
   }
}

Follow the image for the changes made in ZipCodeDriver

Compare the changes made(left side red color) and previous(right side green color)

Sample input:

560036
Chennai
Tamil Nadu
560034
Bangalore
Karnataka

Output:
Loaded 2 zip codes
Hello, please enter zip code to search (type done to stop): 560036
Found 560036: [ZipCode: 560036, Town: Chennai, State: Tamil Nadu]
Hello, please enter zip code to search (type done to stop): 560034
Found 560034: [ZipCode: 560034, Town: Bangalore, State: Karnataka]
Hello, please enter zip code to search (type done to stop): 10001
Sorry but the zip code entered was not found
Hello, please enter zip code to search (type done to stop): done

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