java - 类无法实例化

Question

我创建了一个名为 Account 的类。然后我实例化类型类的对象。所有代码都保存在文件 TestAccount.txt 中。但系统给我一个错误，如下所示

Exception in thread "main" java.lang.ExceptionInInitializerError at testaccount.TestAccount.main(TestAccount.java:8) Caused by: java.lang.RuntimeException: Uncompilable source code - class Account is public, should be declared in a file named Account.java at testaccount.Account.(TestAccount.java:20) ... 1 more Java Result: 1

下面是我的代码:

package testaccount;

public class TestAccount
{
public static void main(String[] args)
{

Account Account1=new Account();
Account1.setId(1122);
Account1.setBalance(20000);
Account1.setAnnualInterestRate(4.5);
System.out.println("The monthly interest rate is " + Account1.getMonthlyInterestRate());
System.out.println("The balance after the withdrawal is "+ Account1.withdraw(2000));
System.out.println("The balabce after the deposit is " + Account1.deposit(3000));

}

}

public class Account 
   {
      private int id;
      private double balance;
      private double annualInterestRate;
      private static long dateCreated;

      public Account()
      {
          id=0;
          balance=0;
          annualInterestRate=0;
          dateCreated=System.currentTimeMillis();
      }

      public Account(int newId,double newBalance)
      {
          id=newId;
          balance=newBalance;
      }

      public int getId()
      {
          return id;
      }
      public void setId(int newId)
      {
           id=newId;
      }

      public double getbalance()
      {
          return balance;
      }
      public void setBalance(double newBalance)
      {
           balance=newBalance;
      }

      public double getAnnualInterestRate()
      {
          return annualInterestRate;
      }
      public void setAnnualInterestRate(double newAnnualInterestRate)
      {
           annualInterestRate=newAnnualInterestRate;
      }

      public static long getDateCreate()
      {
          return dateCreated;
      }

      public double getMonthlyInterestRate()
      {
          return (annualInterestRate/12);
      }

      public double withdraw(double newWithdraw)
      {
          return (balance-newWithdraw);
      }

      public double deposit(double deposit)
      {
          return (balance+deposit);
      }
}

有人可以告诉我我做错了什么吗？

Answer 1

您必须创建一个名为 Account.java 的新文件，并将您的帐户类放入其中。这是因为当您从另一个类调用 account 时，jvm 将查找 Account.class 并且如果您的 account 类位于名为 TestAccount.class 的文件中，则它不会能够找到它。

否则编译器将不会编译您的文件

只要您的两个类位于同一个包(文件夹)中，您就不必执行任何特殊操作来“链接”这两个类。

当然，除非您想要嵌套这些类，在这种情况下，您可以将 Account 类放入 TestAccount 类中。虽然我不推荐这样做，因为它很困惑。