Question

Define a class StatePair with two generic types (Type1 and Type2), a constructor, mutators, accessors, and a printInfo() method. Three ArrayLists have been pre-filled with StatePair data in main():

• ArrayList<StatePair> zipCodeState: Contains ZIP code/state abbreviation pairs

• ArrayList<StatePair> abbrevState: Contains state abbreviation/state name pairs

• ArrayList<StatePair> statePopulation: Contains state name/population pairs

Complete main() to use an input ZIP code to retrieve the correct state abbreviation from the ArrayList zipCodeState. Then use the state abbreviation to retrieve the state name from the ArrayList abbrevState. Lastly, use the state name to retrieve the correct state name/population pair from the ArrayList statePopulation and output the pair.

Ex: If the input is:

21044

the output is:

Maryland: 6079602

StatePair.java

public class StatePair <Type1 extends Comparable, Type2 extends Comparable> {
   private Type1 value1;
   private Type2 value2;
   
   // TODO: Define a constructor, mutators, and accessors 
   //       for StatePair
   
   // TODO: Define printInfo() method
}

StatePopulations.java

import java.util.Scanner;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;

public class StatePopulations {

   public static ArrayList<StatePair> fillArray1(ArrayList<StatePair> statePairs, 
                                                                  Scanner inFS) {
      StatePair pair;
      int intValue;
      String stringValue;

      while (inFS.hasNextLine()) {
         intValue = inFS.nextInt();
         stringValue = inFS.next();
         pair = new StatePair (intValue, stringValue);
         statePairs.add(pair);
      }    
      return statePairs;
   }
   
   public static ArrayList<StatePair> fillArray2(ArrayList<StatePair> statePairs, 
                                                                 Scanner inFS) {
      StatePair pair;
      String stringValue1;
      String stringValue2;

      while (inFS.hasNextLine()) {
         stringValue1 = inFS.next();
         inFS.nextLine();
         stringValue2 = inFS.nextLine();
         pair = new StatePair (stringValue1, stringValue2);
         statePairs.add(pair);
      }
      return statePairs;
   }
   
   public static ArrayList<StatePair> fillArray3(ArrayList<StatePair> statePairs, 
                                                                  Scanner inFS) {
      StatePair pair;
      String stringValue;
      int intValue;

      while (inFS.hasNextLine()) {
         stringValue = inFS.nextLine();
         intValue = inFS.nextInt();
         inFS.nextLine();
         pair = new StatePair (stringValue, intValue);
         statePairs.add(pair);
      } 
      return statePairs;
   }
   
   
   public static void main(String[] args) throws IOException {
      Scanner scnr = new Scanner(System.in);
      FileInputStream fileByteStream = null; // File input stream
      Scanner inFS = null;                   // Scanner object
      int myZipCode;
      int i;
      
      // ZIP code - state abbrev. pairs
      ArrayList<StatePair> zipCodeState = new ArrayList<StatePair>();
      
      // state abbrev. - state name pairs
      ArrayList<StatePair> abbrevState = new ArrayList<StatePair>(); 
      
      // state name - population pairs
      ArrayList<StatePair> statePopulation = new ArrayList<StatePair>();
      
      // Fill the three ArrayLists
      
      // Try to open zip_code_state.txt file
      fileByteStream = new FileInputStream("zip_code_state.txt");
      inFS = new Scanner(fileByteStream);
      zipCodeState = fillArray1(zipCodeState, inFS);
      fileByteStream.close(); // close() may throw IOException if fails
      
      // Try to open abbreviation_state.txt file
      fileByteStream = new FileInputStream("abbreviation_state.txt");
      inFS = new Scanner(fileByteStream);
      abbrevState = fillArray2(abbrevState, inFS);
      fileByteStream.close();
      
      // Try to open state_population.txt file
      fileByteStream = new FileInputStream("state_population.txt");
      inFS = new Scanner(fileByteStream);
      statePopulation = fillArray3(statePopulation, inFS);
      fileByteStream.close();
      
      // Read in ZIP code from user
      myZipCode = scnr.nextInt();
        
      for (i = 0; i < zipCodeState.size(); ++i) {
         // TODO: Using ZIP code, find state abbreviation
      }
      
      
      for (i = 0; i < abbrevState.size(); ++i) {
         // TODO: Using state abbreviation, find state name
      }
      
      
      for (i = 0; i < statePopulation.size(); ++i) {
         // TODO: Using state name, find population. Print pair info.
      }
   }
}

Answer 1

StatePopulations.java

import java.util.Scanner;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;

public class StatePopulations {
   
   public static ArrayList> fillArray1(ArrayList> statePairs, Scanner inFS) {
      
      StatePair pair;
      
      int intValue;
      String stringValue;
      
      while (inFS.hasNextLine()) {
         
         intValue = inFS.nextInt();
         stringValue = inFS.next();
         pair = new StatePair (intValue, stringValue);
         statePairs.add(pair);
         
      }
      
      return statePairs;
      
   }
   
   public static ArrayList> fillArray2(ArrayList> statePairs, Scanner inFS) {
      
      StatePair pair;
      
      String stringValue1;
      String stringValue2;
      
      while (inFS.hasNextLine()) {
         
         stringValue1 = inFS.next();
         inFS.nextLine();
         stringValue2 = inFS.nextLine();
         pair = new StatePair (stringValue1, stringValue2);
         statePairs.add(pair);
         
      }
      
      return statePairs;
      
   }
   
   public static ArrayList> fillArray3(ArrayList> statePairs, Scanner inFS) {
      
      StatePair pair;
      
      String stringValue;
      int intValue;
      
      while (inFS.hasNextLine()) {
         
         stringValue = inFS.nextLine();
         intValue = inFS.nextInt();
         inFS.nextLine();
         pair = new StatePair (stringValue, intValue);
         statePairs.add(pair);
         
      }
      
      return statePairs;
      
   }
   
   public static void main(String[] args) throws IOException {
      
      Scanner scnr = new Scanner(System.in);
      FileInputStream fileByteStream = null; // File input stream
      
      Scanner inFS = null; // Scanner object
      int myZipCode;
      int i;
      
      // ZIP code - state abbrev. pairs
      ArrayList> zipCodeState = new ArrayList>();
      
      // state abbrev. - state name pairs
      ArrayList> abbrevState = new ArrayList>(); 
      
      // state name - population pairs
      ArrayList> statePopulation = new ArrayList>();
      
      // Fill the three ArrayLists
      
      // Try to open zip_code_state.txt file
      
      fileByteStream = new FileInputStream("zip_code_state.txt");
      inFS = new Scanner(fileByteStream);
      zipCodeState = fillArray1(zipCodeState, inFS);
      fileByteStream.close(); // close() may throw IOException if fails
      
      // Try to open abbreviation_state.txt file
      
      fileByteStream = new FileInputStream("abbreviation_state.txt");
      inFS = new Scanner(fileByteStream);
      abbrevState = fillArray2(abbrevState, inFS);
      fileByteStream.close();
      
      // Try to open state_population.txt file
      
      fileByteStream = new FileInputStream("state_population.txt");
      inFS = new Scanner(fileByteStream);
      statePopulation = fillArray3(statePopulation, inFS);
      fileByteStream.close();
      
      // Read in ZIP code from user
      myZipCode = scnr.nextInt();
      
      String stateName = null;
      String stateAbb = null;
      boolean found = false;
      
      for (i = 0; i < zipCodeState.size(); ++i) {
         
         // TODO: Using ZIP code, find state abbreviation
         
         if (zipCodeState.get(i).getValue1() == myZipCode) {
            stateAbb = zipCodeState.get(i).getValue2();
            break;
         }
         
      }
      
      if (stateAbb != null) {
      
         for (i = 0; i < abbrevState.size(); ++i) {
            
            // TODO: Using state abbreviation, find state name
            
            if (abbrevState.get(i).getValue1().equalsIgnoreCase(stateAbb)) {
               stateName = abbrevState.get(i).getValue2();
               break;
            }
            
         }
         
         if (stateName != null) {
            
            for (i = 0; i < statePopulation.size(); ++i) {
               
               // TODO: Using state name, find population. Print pair info.
               
               if (statePopulation.get(i).getValue1().equalsIgnoreCase(stateName)) {
                  statePopulation.get(i).printInfo();
                  found = true;
                  break;
               }
               
            }
            
         }
         
      }
      
      if (!found) {
         System.out.println("Zipcode: " + myZipCode + "not found");
      }
      
   }
   
}

StatePair.java

public class StatePair , Type2 extends Comparable> {
   
   private Type1 value1;
   private Type2 value2;
   
   // TODO: Define a constructor, mutators, and accessors for
   
   public StatePair(Type1 val1, Type2 val2) {
      value1 = val1;
      value2 = val2;
   }
   
   public void setValue1(Type1 val1) {
      this.value1 = val1;
   }
   
   public void setValue2(Type2 val2) {
      this.value2 = val2;
   }
   
   public Type1 getValue1() {
      return value1;
   }
   
   public Type2 getValue2() {
      return value2;
   }
   
   public void printInfo() {
      System.out.println(value1 + ": " + value2);
   }
   
}