这两个类都在同一个包中，所以我很困惑为什么它不起作用。它确实在netbeans中工作，但我现在使用的是Visual Studio Code。我将包含代码和我得到的错误。
分类（包含主要方法）
package project;
import java.util.ArrayList;
import java.util.Scanner;
public class Division
{
public static Scanner scanner = new Scanner(System.in);
public static void main(String[] args)
{
ArrayList<Fighter> fighters = new ArrayList();
fighters.add(new Fighter("Conor McGregor", 29, "Ireland", 21, 3));
fighters.add(new Fighter("Gunnar Nelson", 28, "Iceland", 16, 3));
fighters.add(new Fighter("Stipe Miocic", 33, "USA", 17, 2));
fighters.add(new Fighter("Cody Garbrandt", 26, "USA", 11, 0));
fighters.add(new Fighter("Demetrious Johnson", 30, "USA", 27, 2));
fighters.add(new Fighter("Jose Aldo", 31, "Brazil", 26, 3));
fighters.add(new Fighter("George St Pierre", 40, "Canada", 25, 2));
fighters.add(new Fighter("Fabricio Werdum", 40, "Brazil", 22, 7));
fighters.add(new Fighter("Michael Bisping", 39, "United Kingdom", 30, 7));
displayAllFighters(fighters);
}
//Adds fighter to ArrayList
public static void addFighter(ArrayList<Fighter> fighters)
{
System.out.print("Please enter fighters name: \t");
String name = scanner.nextLine();
System.out.print("\nPlease enter fighters age: \t");
int age = scanner.nextInt();
scanner.nextLine();
System.out.print("\nPlease enter fighters country: \t");
String country = scanner.nextLine();
System.out.print("\nPlease enter amount of wins: \t");
int wins = scanner.nextInt();
System.out.print("\nPlease enter amount of losses: \t");
int losses = scanner.nextInt();
fighters.add(new Fighter(name, age, country, wins, losses));
System.out.println("Fighter Added!");
}
//Removes a fighter from ArrayList
public static void removeFighter(ArrayList<Fighter> fighters)
{
System.out.print("Please enter the name of the fighter you wish to remove: \t");
String name = scanner.nextLine();
for (Fighter fighter : fighters)
{
if (fighter.getName() == name)
{
fighters.remove(fighter);
}
}
}
//Display info of all fighters
public static void displayAllFighters(ArrayList<Fighter> fighters)
{
for (Fighter fighter : fighters)
{
System.out.println(fighter);
System.out.println("==========================================");
}
}
//Counts amount of fighters with a win % that is less that entered value
public static int countWinPercentLowerThan(ArrayList<Fighter> fighters , int value)
{
int count = 0;
for (Fighter fighter : fighters)
{
if (fighter.getPercent() < value)
{
count++;
}
}
return count;
}
//Counts amount of fighters with a win % that is greater that entered value
public static int countWinPercentGreaterThan(ArrayList<Fighter> fighters , int value)
{
int count = 0;
for (Fighter fighter : fighters)
{
if (fighter.getPercent() > value)
{
count++;
}
}
return count;
}
}
战斗机类（编译时无法识别）
package project;
public class Fighter
{
private String name;
private int age;
private String country;
private int wins;
private int losses;
private String weightClass;
public Fighter(String name, int age, String country, int wins, int losses, String weightClass)
{
this.name = name;
this.age = age;
this.country = country;
this.wins = wins;
this.losses = losses;
this.weightClass = weightClass;
}
public Fighter(String name)
{
this.name = name;
this.age = 0;
this.country = "TBA";
this.wins = 0;
this.losses = 0;
this.weightClass = "TBD";
}
public String getName()
{
return this.name;
}
public void setName(String name)
{
this.name = name;
}
public int getAge()
{
return this.age;
}
public void setAge(int age)
{
this.age = age;
}
public String getCountry()
{
return this.country;
}
public void setCountry(String country)
{
this.country = country;
}
public int getWins()
{
return this.wins;
}
public void setWins(int wins)
{
this.wins = wins;
}
public int getLosses()
{
return this.losses;
}
public void setLosses(int losses)
{
this.losses = losses;
}
public String toString()
{
return "Fighter Name: " + this.name + ".\nFighter age: " + this.age + ".\nFighter nation: " + this.country + ".\nFighter wins: " + this.wins + ".\nFighter losses: " + this.losses + ".";
}
public void updateWin()
{
this.wins++;
}
public void updateLosses()
{
this.losses++;
}
public double getPercent()
{
int totalFights = this.wins + this.losses;
double percent = this.wins * 100/totalFights;
return percent;
}
}
错误讯息：
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:34: error: cannot find symbol
public static void addFighter(ArrayList<Fighter> fighters)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:59: error: cannot find symbol
public static void removeFighter(ArrayList<Fighter> fighters)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:74: error: cannot find symbol
public static void displayAllFighters(ArrayList<Fighter> fighters)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:84: error: cannot find symbol
public static int countWinPercentLowerThan(ArrayList<Fighter> fighters , int value)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:99: error: cannot find symbol
public static int countWinPercentGreaterThan(ArrayList<Fighter> fighters , int value)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:15: error: cannot find symbol
ArrayList<Fighter> fighters = new ArrayList();
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:17: error: cannot find symbol
fighters.add(new Fighter("Conor McGregor", 29, "Ireland", 21, 3));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:18: error: cannot find symbol
fighters.add(new Fighter("Gunnar Nelson", 28, "Iceland", 16, 3));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:19: error: cannot find symbol
fighters.add(new Fighter("Stipe Miocic", 33, "USA", 17, 2));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:20: error: cannot find symbol
fighters.add(new Fighter("Cody Garbrandt", 26, "USA", 11, 0));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:21: error: cannot find symbol
fighters.add(new Fighter("Demetrious Johnson", 30, "USA", 27, 2));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:22: error: cannot find symbol
fighters.add(new Fighter("Jose Aldo", 31, "Brazil", 26, 3));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:23: error: cannot find symbol
fighters.add(new Fighter("George St Pierre", 40, "Canada", 25, 2));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:24: error: cannot find symbol
fighters.add(new Fighter("Fabricio Werdum", 40, "Brazil", 22, 7));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:25: error: cannot find symbol
fighters.add(new Fighter("Michael Bisping", 39, "United Kingdom", 30, 7));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:53: error: cannot find symbol
fighters.add(new Fighter(name, age, country, wins, losses));
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:64: error: cannot find symbol
for (Fighter fighter : fighters)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:76: error: cannot find symbol
for (Fighter fighter : fighters)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:88: error: cannot find symbol
for (Fighter fighter : fighters)
^
symbol: class Fighter
location: class Division
c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java:103: error: cannot find symbol
for (Fighter fighter : fighters)
^
symbol: class Fighter
location: class Division
Note: c:\Users\Cian Tiernan\OneDrive - Dundalk Institute of Technology\College\Object Orientated Programming\NetBeansProjects\Java\src\project\Division.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
答案 0 :(得分：-1)
我看到的第一个错误是构造函数需要加权类参数，但是当您使用Fighter类初始化arraylist时，它缺少该值。
例如。 fighters.add（新战斗机（“Conor McGregor”，29，“爱尔兰”，21,3 ））; 缺少体重等级。