Question

所有

下面的代码可以正常使用ArrayList。你可以帮我解决一下如何获取name性别和amountSpent（数组大小[4]）的用户输入，然后用空格分割，以便它有String，String和double。

此外，如何仅显示花费较高的客户的结果，然后显示其他客户的结果。

提前谢谢你！

此致

Viku

import java.util.Comparator;

public  class Customer  implements Comparable <Customer>{

    public String name,gender;
    public double amountSpent;



        public Customer(String name, String gender, double amountSpent) {

            super();
            this.name = name;
            this.gender = gender;
            this.amountSpent = amountSpent;
    }


        public String getCustomername() {

            return name;
    }

        public void setCoustomername(String name) {

            this.name = name;
    }

        public String getgender() {

            return gender;
    }

        public void setGender(String gender) {

            this.gender = gender;
    }

        public double getamountSpent() {

            return  amountSpent;
    }

        public void setamountSpent(double amountSpent) {

            this.amountSpent = amountSpent;
    }

 public static Comparator <Customer> CustomerNameComparator  = new Comparator<Customer>() {


            public int compare(Customer c1, Customer c2) {


                String custName1 = c1.getCustomername().toUpperCase();
                String custName2 = c2.getCustomername().toUpperCase();

                //ascending order
                    //return custName1.compareTo(custName2);

                        //descending order
                            return custName2.compareTo(custName1);
            }
        };

        public static Comparator <Customer> CustomerAmountSpentComparator  = new Comparator<Customer>() {


            public int compare(Customer aS1, Customer aS2) {


                int custamtspent1 = (int) aS1.getamountSpent();
                int custamtSpent2 = (int) aS2.getamountSpent();

                //ascending order sort
                 // return custamtspent1 - custamtSpent2;

                        //descending order sort
                            return custamtSpent2 - custamtspent1;
            }
        };

        @Override
        public int compareTo(Customer o) {
            return 0;
        }

        @Override
        public String toString() {

            return " Customer Name : " + name + ",  Gender : " + gender + ", Amount Spent : " + amountSpent + "";
        }

}

和主要计划：

import java.util.ArrayList;
import java.util.Collections;

public class MainProg {

    public static void main(String args[]){

        String nL = System.lineSeparator();

        try {

        ArrayList<Customer> arraylist = new ArrayList<Customer> ();

        arraylist.add(new Customer ("Louis","Male", 4567.76));
        arraylist.add(new Customer ("Daniela","Female", 7653.67));
        arraylist.add(new Customer ("Jenny","Female", 3476.98));
        arraylist.add(new Customer ("Arijit","Male", 9876.44));


        System.out.println("Customer Name Decending Sort: " + nL);
        Collections.sort(arraylist, Customer.CustomerNameComparator);

            for (Customer str: arraylist) {

                System.out.println(str);

            }

            System.out.println(nL + "Custmer Amount Spent [Hight to Low]  Sorting: " + nL);

                Collections.sort(arraylist, Customer.CustomerAmountSpentComparator);

                for (Customer str: arraylist){
                    System.out.println(str);
                }

            System.out.println(nL + "Highest Amount Spent Custmer Detail: " + nL);



        }


        catch (Exception e){

            System.out.println("Error: " + e);

        }

        finally {

            System.out.println(nL + "Report Completed!");

        }



        }
    }

Answer 1

对于您的第一个问题（如果我已理解正确），您希望将用户输入作为字符串：

戴夫男123.45

然后将其解析为两个字符串和一个双精度数。你提到的扫描仪是一个很好的开始，然后尝试

String [] parts = input.split（“”）;

double value = Double.parseDouble（parts [2]）;

这会将输入拆分为大小为3的String数组，并将第三个元素转换为double对象，这样就可以创建Customers。

对于第二个问题，您可以通过迭代ArrayList中的所有Customers来使用一种简单的方法，并以最高的金额存储当前客户。如果您找到更大的消费者，请更换客户。

Answer 2

Viku，尝试移动

arraylist.add（新客户（name，gender，amountSpent））;

到

之内

do{
  ...
  arraylist.add(new Customer(name,gender,amountSpent));
} while(choice.equalsIgnoreCase("Yes"));

现在代码是，arrayList.add只在循环后执行 - ＆gt;只有最后一次进入。

Answer 3

选项1（建议）：

如果用户要输入数据，为什么需要将其拆分？请按以下步骤操作：

System.out.println("Name:");
name = scn.nextLine();
System.out.println("Gender:");
gender = scn.nextLine():
System.out.println("Amt:");
amt = scn.nextDouble();

Customer c1 = new Customer (name,gender, amt);

选项2：

或者，如果您希望用户在一行中输入所有内容（以空格分隔），请执行以下操作：

System.out.println("Input name, gender, amt:");
name = scn.next();
gender = scn.next():
amt = scn.next();

Customer c1 = new Customer (name,gender, amt);

节目输出：输入姓名，性别，amt： John Male 33.50

选项3（由您提出要求）：

最后，如果您仍然坚持按空格进行拆分，并且您希望接受以空格分隔的一个字符串中的用户输入：

System.out.println("Input name, gender, amt:");
input = scn.nextLine();
String[] token = input.split(" ");
String name = token[0];
String gender = token[1];
double amt = Double.parseDouble(token[2]);

Customer c1 = new Customer (name,gender, amt);

节目输出：输入姓名，性别，amt： John Male 33.50

Array的java用户输入 - 按空格分割

3 个答案: