每当我的 printAnimals 方法执行时，它都不会停止重复正在打印的内容。我尝试过移动中断语句，并更改程序确定打印内容的方式，但到目前为止没有任何效果。
导入java.util.ArrayList； 导入 java.util.Scanner;
公共类驱动程序{ 私有静态扫描仪 scnr = new Scanner(System.in); // 扫描仪对象
// array lists for dogs and monkeys
private static ArrayList<Dog> dogList = new ArrayList<Dog>();
private static ArrayList<Monkey> monkeyList = new ArrayList<Monkey>();
public static void main(String[] args) {
String menuChoice = ""; // local variable
// static methods
initializeDogList();
initializeMonkeyList();
displayMenu(); // call display menu method
menuChoice = scnr.nextLine(); // get menu choice from user
// loop that displays the menu, accepts user inputs, takes appropriate action
while(!menuChoice.equalsIgnoreCase("q")){ // q causes loop to quit executing
switch(menuChoice) { // execute menuChoice based on user input
case "1": // if user enters 1, execute intakeNewDog method
intakeNewDog(scnr);
break;
case "2": // if user enters 2, execute intakeNewMonkey method
intakeNewMonkey(scnr);
break;
case "3": // if user enters 3, execute reserveAnimal method
reserveAnimal(scnr);
break;
case "4": // if user enters 4, execute printAnimals method
printAnimals("4");
break;
case "5": // if user enters 5, execute printAnimals method
printAnimals("5");
break;
case "6": // if user enters 6, execute printAnimals method
printAnimals("6");
break;
default: // if user input is invalid, print message
if(!menuChoice.equalsIgnoreCase("q")){
System.out.println("\n Invalid input, enter 1-6 or q");
displayMenu(); // call display menu method
menuChoice = scnr.nextLine(); // get menu choice from user
}
break;
}
}
}
// This method prints the menu options
public static void displayMenu() {
System.out.println("\n\n");
System.out.println("\t\t\t\tRescue Animal System Menu");
System.out.println("[1] Intake a new dog");
System.out.println("[2] Intake a new monkey");
System.out.println("[3] Reserve an animal");
System.out.println("[4] Print a list of all dogs");
System.out.println("[5] Print a list of all monkeys");
System.out.println("[6] Print a list of all animals that are not reserved");
System.out.println("[q] Quit application");
System.out.println();
System.out.println("Enter a menu selection");
}
// Adds dogs to a list for testing
public static void initializeDogList() {
Dog dog1 = new Dog("Spot", "German Shepherd", "male", "1", "25.6", "05-12-2019", "United States", "intake", false, "United States");
Dog dog2 = new Dog("Rex", "Great Dane", "male", "3", "35.2", "02-03-2020", "United States", "Phase I", false, "United States");
Dog dog3 = new Dog("Bella", "Chihuahua", "female", "4", "25.6", "12-12-2019", "Canada", "in service", true, "Canada");
dogList.add(dog1);
dogList.add(dog2);
dogList.add(dog3);
}
// Adds monkeys to a list for testing
public static void initializeMonkeyList() {
Monkey monkey1 = new Monkey("Monty", "male", "5", "27","02-10-2024", "United States", "intake", false, "United States", "3", "1.9", "16", "macaque");
monkeyList.add(monkey1);
}
// create intakeNewDog method
public static void intakeNewDog(Scanner scnr) {
// get dog's name and assign value
System.out.println("What is the dog's name?");
String name = scnr.nextLine();
// input validation if dog is already in dogList
for(Dog dog: dogList) {
if(dog.getName().equalsIgnoreCase(name)) {
System.out.println("\n\nThis dog is already in our system\n\n");
return; //returns to menu
}
}
// code to instantiate new dog and add to list
// get dog's breed and assign value
System.out.println("What is the dog's breed?");
String breed = scnr.nextLine();
// get dog's gender and assign value
System.out.println("What is the dog's gender?");
String gender = scnr.nextLine();
// get dog's age and assign value
System.out.println("What is the dog's age?");
String age = scnr.nextLine();
//get dog's weight and assign value
System.out.println("What is the dog's weight?");
String weight = scnr.nextLine();
// get dog's acquisition date and assign value
System.out.println("What is the dog's acquisition date?");
String acquisitionDate = scnr.nextLine();
// get dog's acquisition country and assign value
System.out.println("What is the dog's acquisition country?");
String acquisitionCountry = scnr.nextLine();
// get dog's training status and assign value
System.out.println("What is the dog's training status?");
String trainingStatus = scnr.nextLine();
// get if dog is reserved and assign value
System.out.println("Is this dog reserved?");
boolean reserved = scnr.nextBoolean();
// get country dog is serviced in and assign value
System.out.println("Which country is the dog in service");
String inServiceCountry = scnr.nextLine();
// creates new dog object, includes data for attributes
Dog dog = new Dog(name, breed, gender, age, weight, acquisitionDate,
acquisitionCountry, trainingStatus, reserved, inServiceCountry);
dogList.add(dog); // add new dog to Dog ArrayList
System.out.println("This dog has been added to the Dog List"); // input validation
}
public static void intakeNewMonkey(Scanner scnr) {
// get monkey's name and assign value
System.out.println("What is the monkey's name?");
String name = scnr.nextLine();
// input validation if monkey is already in monkeyList
for (Monkey monkey : monkeyList) {
if (monkey.getName().equalsIgnoreCase(name)) {
System.out.println("\n\nThis monkey is already in our system\n\n");
return; //returns to menu
}
}
// get monkey's gender and assign value
System.out.println("What is the monkey's gender?");
String gender = scnr.nextLine();
// get monkey's age and assign value
System.out.println("What is the monkey's age?");
String age = scnr.nextLine();
//get monkey's weight and assign value
System.out.println("What is the monkey's weight?");
String weight = scnr.nextLine();
// get monkey's acquisition date and assign value
System.out.println("What is the monkey's acquisition date?");
String acquisitionDate = scnr.nextLine();
// get monkey's acquisition country and assign value
System.out.println("What is the monkey's acquisition country?");
String acquisitionCountry = scnr.nextLine();
// get monkey's training status and assign value
System.out.println("What is the monkey's training status?");
String trainingStatus = scnr.nextLine();
// get if monkey is reserved and assign value
System.out.println("Is this monkey reserved?");
boolean reserved = scnr.nextBoolean();
// get country monkey is serviced in and assign value
System.out.println("Which country is the monkey in service");
String inServiceCountry = scnr.nextLine();
// get monkey's tail length and assign value
System.out.print("What is the monkey's tail length");
String tailLength = scnr.nextLine();
// get monkey's height and assign value
System.out.print("What is the monkey's height");
String height = scnr.nextLine();
// get monkey's body length and assign value
System.out.print("What is the monkey's body length");
String bodyLength = scnr.nextLine();
// get monkey's species and assign value
System.out.print("What is the monkey's species");
String species = scnr.nextLine();
// creates new monkey object, includes data for attributes
Monkey monkey = new Monkey(name, gender, age, weight, acquisitionDate, acquisitionCountry, trainingStatus, reserved, inServiceCountry, tailLength, height, bodyLength, species);
monkeyList.add(monkey); // add new monkey to Monkey ArrayList
System.out.println("This monkey has been added to the Monkey List");
}
// reserveAnimal method
public static void reserveAnimal(Scanner scnr) {
// get animal type
System.out.println("Would you like to reserve a dog or a monkey?");
String animalType = scnr.nextLine();
// get country
System.out.println("Which country will the " + animalType + " be serving in?");
String serviceLocation = scnr.nextLine(); // correct variable??
// if animal type is dog
if (animalType.equalsIgnoreCase("dog")) {
// Search dog ArrayList for a dog that matches serviceLocation of country entered.
for (Dog dog : dogList) {
// if service location matches country and not reserved
if (dog.getInServiceLocation().equalsIgnoreCase(serviceLocation) && !dog.getReserved()) {
// set reserved to true
dog.setReserved(true);
dog.setInServiceCountry(serviceLocation);
// output found message to user
System.out.println(dog.getName() + " has been reserved.");
return;
}
}
}
else {
// Search monkey ArrayList for a monkey that matches service location of country entered
for (Monkey monkey : monkeyList) {
// if service location matches country and not reserved
if (monkey.getInServiceLocation().equalsIgnoreCase(serviceLocation) && !monkey.getReserved()) {
// set reserved to true
monkey.setReserved(true);
monkey.setInServiceCountry(serviceLocation);
// output found message to user
System.out.println(monkey.getName() + " has been reserved.");
return;
}
}
}
}
// printAnimals method
public static void printAnimals(String printAnimals) {
switch (printAnimals) {
case "4":
System.out.println("All dogs: ");
// output all dogs in dogList
//for (Dog dog: dogList) {
for (int i = 0; i < dogList.size(); ++i) {
Dog dog = dogList.get(i);
System.out.print(dog.getName());
}
break;
case "5":
System.out.println("All monkeys: ");
// output all monkeys in monkeyList
for (Monkey monkey: monkeyList) {
System.out.print(monkey.getName());
}
break;
case "6":
System.out.println("All available animals: ");
// Output all animals that are not reserved
for (Dog dog : dogList) {
if (!dog.getReserved()) {
System.out.println(dog);
}
}
for (Monkey monkey : monkeyList) {
if (!monkey.getReserved()) {
System.out.println(monkey);
}
}
break;
default:
System.out.println("Invalid input for printAnimals.");
}
}
}
您在循环之前获得用户的选择，然后不再更新它。因此，无论选择是什么，你都会永远循环。我会用 do-while
代替。
// loop that displays the menu, accepts user inputs, takes appropriate action
do {
menuChoice = scnr.nextLine(); // get menu choice from user
// ...
default: // if user input is invalid, print message
if(!menuChoice.equalsIgnoreCase("q")){
System.out.println("\n Invalid input, enter 1-6 or q");
displayMenu(); // call display menu method
menuChoice = scnr.nextLine(); // get menu choice from user
}
break;
}
} while(!menuChoice.equalsIgnoreCase("q"));