Question

如何在主类中调用非静态方法。我在示例控制台应用程序中收到以下错误

Exception in thread "main" java.lang.RuntimeException: Uncompilable source code - non-static method doSomthing() cannot be referenced from a static context
        at sample.Main.main(Main.java:20)

，代码是，

public class Main  {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
       doSomthing();
       System.out.print("From Main");
    }

    protected void doSomthing()
    {
        System.out.print("From Main doSomthing");
    }


}

Answer 1

问题是你在静态方法中使用了非静态方法，这在java中是不允许的，将doSomthing（）更改为静态方法

protected static void doSomthing()
{
    System.out.print("From Main doSomthing");
}

或者创建Main类的对象并将其命名为

 public static void main(String[] args) {
   Main myMain = new Main();
   myMain.doSomthing();
   System.out.print("From Main");
}

Answer 2

您可以先使用static main方法创建实例：

new Main().doSomthing();

Answer 3

除非您实例化一个[Main class]，否则不能在主类中调用非静态方法。

Answer 4

public class Main  {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
       Main main = new Main();
       main.doSomthing();
       System.out.print("From Main");
    }

    protected void doSomthing()
    {
        System.out.print("From Main doSomthing");
    }
}

线程“main”中的异常java.lang.RuntimeException：无法编译的源代码

4 个答案: