我对Java类和驱动程序真的很困惑。驱动程序代码的语法是什么，里面应该有什么，不应该有什么？对于驱动程序，我们可能需要在其中包含一个主程序，但是 Java 类呢，我们不需要吗？
我需要在 Java 类和驱动程序中都有这个，还是只在驱动程序中：
public static void main(String[] args) {
}
从这里引用：
“驱动程序类”通常只是包含主类的类。在一个 实际项目中，你可能经常有无数的“驱动类”用于测试 等等，或者你可以在你的任何对象中构建一个 main 和 通过您的 IDE 选择可运行的类，或者通过简单地指定 “Java 类名。”
例子：
这不是驱动程序类，因为它不包含任何主要方法。在这种情况下，它有方法“你好”：
public class HelloWorld {
public void hello() {
System.out.println("Hello, world!");
}
}
相对于这个 - 这是一个驱动程序类，因为它包含一个主要方法，和是runsHelloWorld的类：
public class HelloWorldDriver {
public static void main(String[] args) {
HelloWorld sayhello = new HelloWorld();
sayhello.hello();
}
}
因此得名“驱动程序类”——作为 HelloWorldDriver 类“drives”或者更确切地说，controls HelloWorld 类的实例化和使用。
你应该阅读 https://docs.oracle.com/javase/6/docs/api/java/sql/Driver.html 这定义了一个 JDBC 驱动程序。如果你想创建你的 JDBC 驱动程序，只需创建一个实现此接口的类（这比它看起来更复杂，因为必须定义一个特定的
Connexion在任何情况下，当您需要使用或实现驱动程序时，您应该有一个接口参考（音频、JDBC、图形、串行接口、XML 解析器、脚本语言……），它定义了您的驱动程序提供哪些方法。
您可以定义自己的驱动方案。然后你定义一个接口，一个或多个实现。通常，驱动程序是动态加载的。那么
Connection connection = DriverManager.getConnection("jdbc:mariadb://localhost:3306/DB?user=root&password=myPassword");
将加载 MariaDB 驱动程序。
如果驱动程序类名来自配置文件（这使您的程序可移植），
my_class = driver_name.getClass()(MyDriverInterface)my_class.newInstance()import java.util.ArrayList;
import java.util.Scanner;
public class Driver {
private static ArrayList<Dog> dogList = new ArrayList<Dog>();
// Instance variables (if needed)
private static ArrayList<Monkey> monkeyList = new ArrayList<Monkey>();
public static void main(String[] args) {
String userInput;
initializeDogList();
initializeMonkeyList();
displayMenu();
Scanner scanner = new Scanner(System.in);
userInput = scanner.next().toUpperCase();
while (userInput != "Q") {
if ((userInput != "1") && (userInput != "2") && (userInput != "3")
&& (userInput != "4") && (userInput != "5") && (userInput != "6")) {
System.out.println("Invalid Entry");
displayMenu();
userInput = scanner.next().toUpperCase();
}
else if (userInput == "1") {
intakeNewDog(scanner);
break;
}
else if (userInput == "2") {
intakeNewMonkey(scanner);
break;
}
else if (userInput == "3") {
reserveAnimal(scanner);
break;
}
else if (userInput == "4") {
int number = Integer.parseInt(userInput);
printAnimals(number);
break;
}
else if (userInput == "5") {
int number = Integer.parseInt(userInput);
printAnimals(number);
break;
}
else if (userInput == "6") {
int number = Integer.parseInt(userInput);
printAnimals(number);
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("Moca", "German Shepherd", "male", "1", "25.6", "05-12-2019", "United States", "intake", false, "United States");
Dog dog2 = new Dog("Smokey", "Great Dane", "male", "3", "35.2", "02-03-2020", "United States", "Phase I", false, "United States");
Dog dog3 = new Dog("Pickles", "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
//Optional for testing
public static void initializeMonkeyList() {
Monkey monkey1 = new Monkey("Chuckles", "Mandorin", "Female", "2", "200", "8'3", "2'", "Normal", "4/10/2023", "South America", "trained", "reserved", "service");
Monkey monkey2 = new Monkey("Nitro", "Chimpanzee", "Male", "3", "400", "7", "10'", "Muscular", "4/10/2023", "United States", "Rescue", "reserved", "service Bouncer");
Monkey monkey3 = new Monkey("Flower", "Mandorin", "Female", "2", "50", "2", "6'","Normal", "4/10/2023", "Turkey", "trained", "Rescue", "service");
monkeyList.add(monkey1);
monkeyList.add(monkey2);
monkeyList.add(monkey3);
}
public static void intakeNewDog(Scanner scanner) {
System.out.println("What is the dog's name?");
String name = scanner.nextLine();
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
}
}
System.out.println("What is the dog's breed?");
String breed = scanner.nextLine();
System.out.println("What is the dog's gender?");
String gender = scanner.nextLine();
System.out.println("What is the dog's age?");
String age = scanner.nextLine();
System.out.println("What is the dog's weight?");
String weight = scanner.nextLine();
System.out.println("What is the dog's acquisition date?");
String acquisitionDate = scanner.nextLine();
System.out.println("What is the dog's acquisition location?");
String acquisitionCountry = scanner.nextLine();
System.out.println("What is the dog's training status?");
String trainingStatus = scanner.nextLine();
System.out.println("Is the dog reserved?");
boolean reserved = scanner.nextBoolean();
System.out.println("What is the dog's service country?");
String inServiceCountry = scanner.nextLine();
Dog newDog = new Dog(name, breed, gender, age, weight, acquisitionDate, acquisitionCountry, trainingStatus, reserved, inServiceCountry);
dogList.add(newDog);
System.out.println("Dog added to list");
}
public static void intakeNewMonkey(Scanner scanner) {
System.out.println("What is the monkey's name?");
String name = scanner.nextLine();
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
}
}
System.out.println("What is the monkey's species?");
String species = scanner.nextLine();
System.out.println("What is the monkey's gender?");
String gender = scanner.nextLine();
System.out.println("What is the monkey's age?");
String age = scanner.nextLine();
System.out.println("What is the monkey's weight?");
String weight = scanner.nextLine();
System.out.println("What is the monkey's height?");
String height = scanner.nextLine();
System.out.println("What is the monkey's tail length?");
String tail = scanner.nextLine();
System.out.println("What is the monkey's body length?");
String body = scanner.nextLine();
System.out.println("What is the monkey's acquisition date?");
String date = scanner.nextLine();
System.out.println("What is the monkey's acquisition location?");
String country = scanner.nextLine();
System.out.println("What is the monkey's training status?");
String training = scanner.nextLine();
System.out.println("Is the monkey reserved?");
boolean reserved = scanner.nextBoolean();
System.out.println("What is the monkey's service country?");
String service = scanner.nextLine();
Monkey newMonkey = new Monkey(name, species, gender, age, weight, height, tail, body, date, country, training, reserved, service);
monkeyList.add(newMonkey);
System.out.println("Monkey added to list");
}
public static void reserveAnimal(Scanner scanner) {
scanner.nextLine();
System.out.println("Enter animal type: ");
String animalType = scanner.nextLine();
if (animalType.equalsIgnoreCase("Monkey")) {
System.out.println("Enter the monkey's country of acquisiton: ");
String country = scanner.nextLine();
for(Monkey obj: monkeyList) {
if(obj.getAcquisitionLocation().equalsIgnoreCase(country)) {
obj.setReserved(true);
System.out.println("This monkey is now reserved.");
return;
}
}
System.out.println("The monkey entered is not in the list");
}
else if (animalType.equalsIgnoreCase("Dog")) {
System.out.println("Enter the dog's country of acquisition: ");
String country = scanner.nextLine();
for(Dog obj: dogList){
if(obj.getAcquisitionLocation().equalsIgnoreCase(country)){
obj.setReserved(true);
System.out.println("This dog is now reserved.");
return;
}
}
System.out.println("The dog entered is not in the list");
} else {
System.out.println("Type not found");
}
}
public static void printAnimals(int option) {
if (option == '4') {
System.out.println(dogList);
}
else if (option == '5') {
System.out.println(monkeyList);
}
else if (option == '6') {
// Iterates through dogs
for (int i = 0; i < dogList.size(); i++) {
if (dogList.get(i).getTrainingStatus().equals("in service") &&
dogList.get(i).getReserved()==false) {
// Prints dogs that are in service and available
System.out.println(dogList.get(i));
}
}
// Iterates through monkeys
for (int i = 0; i < monkeyList.size(); i++) {
if (monkeyList.get(i).getTrainingStatus().equalsIgnoreCase("in service") &&
monkeyList.get(i).getReserved()==false) {
// Prints monkeys that are in service and available
System.out.println(monkeyList.get(i));
}
}
}
}
}