Java 错误 - 源文件错误:文件不包含类 x .请删除或确保它出现

While learning packages, tried this and got an error message. What I did was,

    //Creating class A (Within package the package: com.test.helpers)

    package com.test.helpers;
    public class A {
        public void sayHello(){
            System.out.println("Hello World");
        }
    }

<小时>

    //And then the class App utilizing the class A

    import com.test.helpers.*;

    public class App{
        public static void main(String args[]){
            A a = new A();
            a.sayHello();
        }
    }

<小时>

我将这两个文件放在一个名为JavaTest"的目录中(在 Windows 7 上)，并首先使用命令 javac -d 编译 A.java.A.java

然后，在尝试编译 App.java 时，我收到以下错误消息:

    App.java:5: error: cannot access A
                    A a = new A();
                    ^
      bad source file: .A.java
        file does not contain class A
        Please remove or make sure it appears in the correct subdirectory of the source path.
    1 error