java - Eclipse 说选择不包含主要类型？

Question

我不确定为什么当我有一个 main 时它会这样说？我不确定发生了什么。任何帮助将不胜感激。谢谢。

public class Feet {

    public static void main(String[] args) {
        System.out.printf("%-15s%-15s|%-15s%-15s\n","Feet","Meters","Meters","Feet");
        System.out.println( String.format("%62s"," ").replace(' ', '-') );

        for (int m = 20, f = 1  ; f <=10; f++, m+=5) {
            System.out.printf("%-15.1f%-15.3f | %-15.1f%-15.3f\n", (float) f, footToMeter (f), (float) m, meterToFoot (m));
        }
    }

    /** Convert from meter to foot */
    public static double meterToFoot(double meter) {
        return 3.279 * meter;
    }

    /** Convert from foot to meter */
    public static double footToMeter(double foot) {
        return  0.305 * foot;
    }

}

Answer 1

右键单击您放置主类的文件夹，然后单击

Build Path --> Use as Source Folder

.最后将您的主文件作为 java 应用程序运行。希望这个问题能得到解决。