Question

我正在编写一个程序，它有四个类，Circle，Rectangle，GeometricObject和我的主要一个TestGeometricObject。我不明白如何使用TestGeometricObject读取记事本等其他文件？

我不需要帮助阅读课程我现在只需要帮助如何连接我所读取的另一个文件，例如记事本上的文件，不仅仅是这个程序，还有我要写的任何程序？我希望这是有道理的......如果没有，请告诉我。

 public class TestGeometricObject {
         public static void main(String[] args) {

        GeometricObject geoObject1 = new Circle();

    GeometricObject geoObject2 = new Rectangle();

    System.out.println("The two objects have the same area? " +
      equalArea(geoObject1, geoObject2));

    // Display circle
    displayGeometricObject(geoObject1);

    // Display rectangle
    displayGeometricObject(geoObject2);
  }



public static boolean equalArea(GeometricObject object1,GeometricObject object2) {

    return object1.getArea() == object2.getArea();
  }
  public static void displayGeometricObject(GeometricObject object) {
    System.out.println();
    System.out.println("The area is " + object.getArea());
    System.out.println("The perimeter is " + object.getPerimeter());
  }
}//end main

    public class Circle extends GeometricObject {
      private double radius;

      public Circle() {
      }

      public Circle(double radius) {
        this.radius = radius;
      }

      /** Return radius */
      public double getRadius() {
        return radius;
      }

      /** Set a new radius */
      public void setRadius(double radius) {
        this.radius = radius;
      }

   /** Return area */


        public double getArea() {
            return radius * radius * Math.PI;
          }

          /** Return diameter */
          public double getDiameter() {
            return 2 * radius;
          }

     /** Return perimeter */
          public double getPerimeter() {
            return 2 * radius * Math.PI;
          }

          /* Print the circle info */
          public void printCircle() {
            System.out.println("The circle is created " + getDateCreated() +
              " and the radius is " + radius);
          }
        }//end

    public class Rectangle extends GeometricObject {
      private double width;
      private double height;

      public Rectangle() {
      }

      public Rectangle(double width, double height) {
        this.width = width;
        this.height = height;
      }

      /** Return width */
      public double getWidth() {
        return width;
      }

      /** Set a new width */
      public void setWidth(double width) {
        this.width = width;
      }

      /** Return height */
      public double getHeight() {
        return height;
      }

      /** Set a new height */
      public void setHeight(double height) {
        this.height = height;
      }
    /** Return area */
      public double getArea() {
        return width * height;
      }

     /** Return perimeter */
      public double getPerimeter() {
        return 2 * (width + height);
      }
    }//end

public abstract class GeometricObject {
  private String color = "white";
  private boolean filled;
  private java.util.Date dateCreated;

  /** Construct a default geometric object */
  protected GeometricObject() {
    dateCreated = new java.util.Date();
  }

  /** Construct a geometric object with color and filled value */
  protected GeometricObject(String color, boolean filled) {
    dateCreated = new java.util.Date();
    this.color = color;
    this.filled = filled;
  }

  /** Return color */
  public String getColor() {
    return color;
  }

  /** Set a new color */
  public void setColor(String color) {
    this.color = color;
  }

  /** Return filled. Since filled is boolean,
   *  the get method is named isFilled */
  public boolean isFilled() {
    return filled;
  }

  /** Set a new filled */
  public void setFilled(boolean filled) {
    this.filled = filled;
  }

  /** Get dateCreated */
  public java.util.Date getDateCreated() {
    return dateCreated;
  }


  public String toString() {
    return "created on " + dateCreated + "\ncolor: " + color +
      " and filled: " + filled;
  }

  /** Abstract method getArea */
  public abstract double getArea();

  /** Abstract method getPerimeter */
  public abstract double getPerimeter();
}//end

Answer 1

要阅读文本文件，通常的做法是使用BufferedReader包装并FileReader

try {
  BufferedReader br = new BufferedReader(new FileReader(new File("yourFile.txt")));
  String line;
  while ((line = br.readLine()) != null) {
    System.out.println(line);
  }
  br.close();
} catch (IOException e) {
  e.printStackTrace();
}

Java-使用类并读取文件

1 个答案: