我正在努力要求一个位于与主类不同的包中的函数。我正在谈论的功能是以下之一：wtchPrdct = createWatch(keyboard);
它位于我的主要功能内，以创建如下所示的Watch对象Watch wtchPrdct = null;
因为我的程序在添加内容时变得很长，所以我想从主类中减轻一些负担，因此，我创建了一个“ Utils”包，并在其中添加了createWatch（）函数。
但是，我现在很难调用该函数。
如果我坚持原来的行，就会出现“找不到错误的符号”：wtchPrdct = createWatch(keyboard);
并更改我这样校准方法的方式：Create wtchPrdct = new Create();wtchPrdct = createWatch(keyboard);
但不幸的是遇到了同样的错误。
我忘了提到我已经导入了我的包裹：import Utils.Create;
package SportswearProduct;
import DBClass.Model;
import java.sql.SQLException;
import java.util.*;
import java.sql.Date;
import Utils.Create;
public class SSD_CA2 {
public static void main(String[] args) throws SQLException {
System.out.println("\n================== MENU ==================");
do {
/* the user may choose beetwen CRUD interactions provided by the program */
System.out.println("\n1. Create a new Sportswear");
System.out.println("2. Read Watch");
System.out.println("3. Update Watch");
System.out.println("4. Delete Watch");
System.out.println("5. Exit");
System.out.print("\nEnter option: ");
/* optCommand interprets as a string the command from the user, parse it as an Integer
* & checks whether the command matches one of the CRUD interactions below */
String optCommand = keyboard.nextLine();
opt = Integer.parseInt(optCommand);
// The program prompts a command feedback
System.out.println("\nYou chose option " + opt);
// I use a do-while loop that iterates until the user prompts a correct command (see option 5)
switch (opt) {
case 1: {
System.out.println("\nWhat product would you like to add?");
System.out.println("1. A Watch");
System.out.println("2. Runners");
System.out.print("\nEnter option: ");
String createCmd = keyboard.nextLine();
int newOpt = Integer.parseInt(createCmd);
do {
switch (newOpt) {
case 1: {
System.out.println("\n================== Create Watch ==================");
/* spwrPrdct will store the data of an object watch created in the function createWatch to which we pass
* as a parameter the method Scanner() */
Create wtchPrdct = new Create();
wtchPrdct = createWatch(keyboard);
// once returned, prdctWatch id passed to the addWatch() function in Model.java
model.addWatch(wtchPrdct);
break;
}
case 2: {
//same process as above
System.out.println("\n================== Create Runners ==================");
runPrdct = createRunners(keyboard);
model.addRunners(runPrdct);
break;
}
default:
if (opt > 2) {
/* if the user inputs a value greater than 5, instead of stoping, the program prompts an error message
* & iterates again */
System.out.println("\n================== ERROR ==================");
System.out.println("\nWrong command! select one or 2 :");
}
}
break;
} while (newOpt != 1 || newOpt != 2);
}
}
}
这是我的功能：
package Utils;
import SportswearProduct.Sportswear;
import SportswearProduct.Runners;
import SportswearProduct.Watch;
import java.sql.Date;
import java.util.Scanner;
public class Create {
Watch wtchPrdct = null;
/* -------------------- CREATE WATCH FUNCTION -------------------- */
/* createWatch() passes Keyboard()so that the user may assign data to the object */
public static Watch createWatch(Scanner keyboard) {
/* the user enters data that is stored into a variable of matching datat type */
System.out.print("\nEnter the watch brand: ");
String brand = keyboard.nextLine();
System.out.print("Enter the date of sale (yyyy-mm-dd): ");
Date onSale = Date.valueOf(keyboard.nextLine());
...
Watch prdctWatch = new Watch(
brand,
onSale,
price,
movement,
chargingType,
batteryLife,
waterProof
);
return prdctWatch;
我削减了最后一部分，因为它起作用了，并且不想淹没代码。
谢谢你的帮助。
最佳答案
我认为您已经混淆了Java和Pyhon等脚本语言的语法。
由于方法createWatch是在类Create中声明的，因此，当您要调用该方法时，应该：
通过使用类Create的实例来调用该方法：
wtchPrdct = wtchPrdct.createWatch（keyboard）;
或通过将方法设置为static来调用该方法，并使用类名来调用它：
wtchPrdct = Create.createWatch（键盘）;
关于java - 从另一个包中调用一个函数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/60522835/