java - Dr. Java 中的多个类

Question

JDK 编译器说它可以编译，但是当它运行时我收到此错误:

Static Error: This class does not have a static void main method accepting String[].

我习惯将方法类放在一个文件中，并将主类放在一个单独的文件中。

我该如何解决这个问题？

    import java.util.Scanner;

public class Test{
  private final int classSize = 35;
  private int numEnrolled, numNeeded; 

  public void Input(){
   Scanner in = new Scanner(System.in);
   System.out.println("Enter the amount enrolled in your class");
   numEnrolled = in.nextInt();
   System.out.println("Your input is " + numEnrolled);       

   // Other parts of code that needs to be coded 
  }
}

class testRunner{
  static void main(String args[]){
    Test newTest = new Test();
    newTest.Input();

 }}

Answer 1

• 在一个文件中只能有一个公共(public)类，并且可以有多个 非公开类(class)
• 您的文件名必须与唯一公开的文件名匹配 类
• 为了使你的类可以运行，它应该包含一个公共(public)静态 void main(String args[]) 方法，最好在公共(public)类中

您的 TestRunner.java 应该如下所示

class Test{
    private final int classSize = 35;
    private int numEnrolled, numNeeded;

    public void Input(){
        Scanner in = new Scanner(System.in);
        System.out.println("Enter the amount enrolled in your class");
        numEnrolled = in.nextInt();
        System.out.println("Your input is " + numEnrolled);

        // Other parts of code that needs to be coded
    }
}

public class TestRunner{
    public static void main(String args[]){
        Test newTest = new Test();
        newTest.Input();

    }}

编辑: 如果您想保留文件名 Test.java，这也可以:

public class Test {
    private final int classSize = 35;
    private int numEnrolled, numNeeded;

    public void Input() {
        Scanner in = new Scanner(System.in);
        System.out.println("Enter the amount enrolled in your class");
        numEnrolled = in.nextInt();
        System.out.println("Your input is " + numEnrolled);

        // Other parts of code that needs to be coded
    }
}

class TestRunner {
    public static void main(String args[]) {
        Test newTest = new Test();
        newTest.Input();

    }
}