arraylistから値を取得する方法と、選択した国の選択に従って表示する方法はありますか？

Question

私は宣言された配列のリストを持っています。国ごとにどのように値を取得し、結果を1つずつ表示するのですか？

例：国の検索の場合、オプション1：米国を選択する場合。それは私のarraylistからアメリカのすべての結果を一つ一つ取り出すでしょう。それ、どうやったら出来るの ？

public class Assignment { 

     //Declare variables 
     public static String[] country; 
     public static String[] description; 
     public static String[] travelmonth; 
     public static double[] price; 
     public static String[] travelpackage; 
     public static String[] newls; 

    public static void main(String[] args) { 

      country = new String[8]; 
      country[0] = "Australia"; 
      country[1] = "Australia"; 
      country[2] = "Australia"; 
      country[3] = "China"; 
      country[4] = "China"; 
      country[5] = "USA"; 
      country[6] = "USA"; 
      country[7] = "USA"; 

      travelmonth = new String[8]; 
      travelmonth[0] = "June"; 
      travelmonth[1] = "June"; 
      travelmonth[2] = "July"; 
      travelmonth[3] = "August"; 
      travelmonth[4] = "September"; 
      travelmonth[5] = "October"; 
      travelmonth[6] = "October"; 
      travelmonth[7] = "December"; 

      description = new String[8]; 
      description[0] = "6D5N Gold Coast Adventure"; 
      description[1] = "5D4N Melbourne Tour"; 
      description[2] = "6D5N Sydney City and Wine Tour"; 
      description[3] = "4D3N Beijing City and Great Wall Adventure"; 
      description[4] = "5D4N Hangzhou Scenic Tour"; 
      description[5] = "8D7N California Adventure"; 
      description[6] = "6D5N New York Shopping Trip"; 
      description[7] = "8D7N Los Angeles, Las Vegas Winter Wonderland"; 

      price = new double[8]; 
      price[0] = 1600; 
      price[1] = 1405.5; 
      price[2] = 1700; 
      price[3] = 880; 
      price[4] = 990; 
      price[5] = 2500; 
      price[6] = 2106.6; 
      price[7] = 2650.1; 

      travelpackage = new String[8]; 
      travelpackage[0] = "1 of 8"; 
      travelpackage[1] = "2 of 8"; 
      travelpackage[2] = "3 of 8"; 
      travelpackage[3] = "4 of 8"; 
      travelpackage[4] = "5 of 8"; 
      travelpackage[5] = "6 of 8"; 
      travelpackage[6] = "7 of 8"; 
      travelpackage[7] = "8 of 8"; 

      int choice = 0; 

      do { 

       String msg ="Main Menu\n"; 
       msg += "===========\n"; 
       msg+= "1. Display all Travel Packages\n"; 
       msg+= "2. Random tour selection\n"; 
       msg+= "3. Search by country\n"; 
       msg+= "0. Quit"; 

       //choice is an integer, therefore you need to convert 
       choice = Integer.parseInt(JOptionPane.showInputDialog(msg)); 

       if(choice == 1) { 

        displayAllPackages(); 

       } 

       if(choice == 2) { 

        JOptionPane.showMessageDialog(null, "Are you ready for your next holiday?"); 

        generateRandomPackage(); 

       } 

       if(choice == 3) { 

        searchByCountry(); 

       } 

      } 

      while(choice!=0); 

      JOptionPane.showMessageDialog(null, "Thank You for using the system"); 

     } 

    public static void searchByCountry() { 

      List<String> listString = new ArrayList<String>(); 

       listString.add("Australia"); 
       listString.add("Australia"); 
       listString.add("Australia"); 
       listString.add("China"); 
       listString.add("China"); 
       listString.add("USA"); 
       listString.add("USA"); 
       listString.add("USA"); 

      Set<String> setString = new HashSet<String>(listString); 

      listString.clear(); 

      listString.addAll(setString); 

      String msgs = ""; 

      int countryno = 0; 

         msgs = ""; //reset 
         msgs+= "Enter country number\n"; 
         msgs+= "1. " +listString.get(0) + "\n"; 
         msgs+= "2. " +listString.get(1) + "\n"; 
         msgs+= "3. " +listString.get(2) + "\n"; 

      countryno = Integer.parseInt(JOptionPane.showInputDialog(msgs));    

       if(countryno == 1) { 

        showAllUSA1(); 

       } 

    } 

    public static void showAllUSA1() { 

      String msg = ""; 
      int index = 0; 

      String inChoice =""; 

       msg = ""; //reset 
       msg+= "Search result : 1 \n"; 
       msg+= "==============\n"; 
       msg+= "Country : " +country + "\n"; 
       msg+= "Month : " +travelmonth [index] + "\n"; 
       msg+= "Description : " +description [index] + "\n"; 
       msg+= "Price : " +price [index] + "\n"; 
       msg+= "===============\n"; 
       msg+= "Enter M to return to main menu\n"; 

       for(int i=0; i< country.length; i++) 

       System.out.println(i + ":" +country[i]); 
       //inChoice = JOptionPane.showInputDialog(msg); 


      } 

} 

Answer 1

インデックスに関連付けられた配列の束があります。それらを配列に入れるのではなく、それぞれのオブジェクトを作成してみましょう。今、あなたは、配列やリストにそれらを置くことができる

TravelPlan one = new TravelPlan ("Australia", 
           "June", 
           "6D5N Gold Coast Adventure", 
           1600, 
           "1 of 8"); 

：

public class TravelPlan { 
    String country; 
    String description; 
    String travelmonth; 
    double price; 
    String travelpackage; 
    String newls; 

    public TravelPlan() { 
    } 

    public TravelPlan(String country, 
         String description, 
         String travelmonth, 
         double price, 
         String travelpackage) { 
      this.country = country; 
      this.description = description; 
      this.travelmonth = travelmonth; 
      this.price = price; 
      this.travelpackage = travelpackage; 
    } 
    // add setters/getters here for example 
    String getCountry() { 
     return(country); 
    } 
    void setCountry(String country) { 
     this.country = country; 
    } 
    double getPrice() { 
    return(price); 
    } 
    void setPrice(double price) { 
    this.price = price; 
    } 
    // continue with rest of class variables here 
} 

次に、あなたがでそれをインスタンス化することができます。

java.util.List<TravelPlan> travelPlans = new java.util.ArrayList<>(); 
    travelPlans.add(one); 
    // add rest here 

このようにすると、すべての配列がオブジェクトになり、検索が容易になります。

for (TravelPlan s : travelPlans) { 
    if ("USA".equals(s.getCountry()) { 
      //we have a match for USA, do whatever ... 
    } 
} 

travelPlansは、すべての可能なTravelPlansのリストであり、次の方法で国で検索できます。あなたはこれらのフィールドを持つオブジェクトを使用する場合があります

List matches = getListByCountry("USA");