下面的程序不知道哪里错了？大家帮帮忙看一下，谢谢


/**
 * @(#)Java1.java
 *
 * Java1 application
 *
 * @author
 * @version 1.00 2010/10/14
 */
 
   public class Java1 {
   
   
   public  class Shape {
      //构造方法；
     Shape(){
     System.out.println ("Check the Shape!");
    }
 }
     //Triangle类继承Shape类
   public class Triangle extends Shape{
          int a;
          int b;
          int c;
      //子类构造方法；
   public Triangle(int a,int b,int c){
          this.a=a;
          this.b=b;
          this.c=c;
          System.out.println ("Check the Triangle!");
  }
      //输出三角形的面积；
   void getS(){
          float p;
          double s;
          p=(a+b+c)/2;
          s=Math.sqrt((p-a)*(p-b)*(p-c));
   System.out.println ("三角形的面积为："+s);
  }
}



   public static void main(String[] args) {
        
        // TODO, add your application cod
        Triangle a = new Triangle(3,4,5);
        a.getS();
   }
 }
不能运行  无法从静态上下文中引用非静态 变量 this

class Shape {
      //构造方法；
     Shape(){
     System.out.println ("Check the Shape!");
    }


  }
class Triangle extends Shape{
          int a;
          int b;
          int c;
      //子类构造方法；
   public Triangle(int a,int b,int c){
          this.a=a;
          this.b=b;
          this.c=c;
          System.out.println ("Check the Triangle!");
  }
      //输出三角形的面积；
   void getS(){
          float p;
          double s;
          p=(a+b+c)/2;
          s=Math.sqrt((p-a)*(p-b)*(p-c));
   System.out.println ("三角形的面积为："+s);
  }
  public static void main(String[] args) {
        
        // TODO, add your application cod
      
        
        Triangle a = new Triangle(3,4,5);
       a.getS();
   }
}

这样就好了

谢了，我找到结果了，是忽略了内部类的问题
/**
* @(#)Java1.java
*
* Java1 application
*
* @author
* @version 1.00 2010/10/14
*/
   
   public  class Shape {
      //构造方法；
     Shape(){
     System.out.println ("Check the Shape!");
    }
}
     //Triangle类继承Shape类
   public class Triangle extends Shape{
          int a;
          int b;
          int c;
      //子类构造方法；
   public Triangle(int a,int b,int c){
          this.a=a;
          this.b=b;
          this.c=c;
          System.out.println ("Check the Triangle!");
  }
      //输出三角形的面积；
   void getS(){
          float p;
          double s;
          p=(a+b+c)/2;
          s=Math.sqrt(p*(p-a)*(p-b)*(p-c));
   System.out.println ("三角形的面积为："+s);
  }
}
public class Java1 {

   public static void main(String[] args) {
        
        // TODO, add your application cod
        Triangle a = new Triangle(3,4,5);
        a.getS();
   }
}