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java - 获取器和设置器无法正常工作？

问题描述

我试图使用多态性和继承来制作盒子对象，我用于设置宽度的 getter 和 setter 工作得很好，但是对于长度，如果宽度或长度设置不下降，我将它写成与宽度的 getter 和 setter 相同的格式在 MIN 为 3 和 MAX 为 20 之间，将变量设置为最接近的值（例如，如果长度为 24，则设置为 20，如果长度为 2，则设置为 3）无论如何，这很有效宽度可以，长度不行？我很困惑，我不知道为什么。这是我的代码。

盒子.java

package l08;

public class Box {

/** Minimum size for either side of the box */
public static final int MIN = 3;

/** Maximum size for either side of the box */
public static final int MAX = 20;

/** The width of the box */
private int width;

/** The length of the box */
private int length;

/** * A symbol to be used to draw a box */
private char symbol;

/** Boolean to indicate whether the box is filled or not */
private boolean filled;

/**
 * Constructor
 * 
 * @param startWidth
 * @param startLength
 * @param startSymbol
 * @param startFilled
 */
public Box(int startWidth, int startLength, char startSymbol,
        boolean startFilled) {

    if (length < MIN) {
        length = MIN;
    }
    if (length > MAX) {
        length = MAX;
    }

    this.width = startWidth;
    this.length = startLength;
    this.symbol = startSymbol;
    this.filled = startFilled;

    if (width < MIN) {
        width = MIN;
    }
    if (width > MAX) {
        width = MAX;
    }

}// end constructor

/**
 * Draw this box.
 */
public void drawBox() {
    for(int star = 3; star < getLength(); star++) 
System.out.print(getSymbol());
    System.out.print("\n"+getSymbol());
    for(int space = 0; space < getLength()-2; space++) System.out.print(" 
");
    System.out.print(getSymbol() + "\n");
    for(int star = 0; star < getLength(); star++)                 
System.out.print(getSymbol());
    System.out.println();
}

/**
 * Get the value of filled
 *
 * @return the value of filled
 */
public boolean isFilled() {
    return filled;
}

/**
 * Set the value of filled
 *
 * @param newFilled new value of filled
 */
public void setFilled(boolean newFilled) {
    this.filled = newFilled;
}

/**
 * Get the value of symbol
 *
 * @return the value of symbol
 */
public char getSymbol() {
    // Activity 3, implement the getters
    return symbol;
}

/**
 * Set the value of symbol
 *
 * @param newSymbol new value of symbol
 */
public void setSymbol(char newSymbol) {
    this.symbol = newSymbol;
}

/**
 * Get the value of length
 *
 * @return the value of length
 */
public int getLength() {
    return length;
}

/**
 * Set the value of length
 *
 * @param newLength new value of length
 */
public void setLength(int newLength) {
    if (length >= MIN || length <= MAX) {
        length = newLength;
    }
}

/**
 * Get the value of width
 *
 * @return the value of width
 */
public int getWidth() {
    // Activity 3, implement the getters
    return width;
}

/**
 * Set the value of width
 *
 * @param newWidth new value of width
 */
public void setWidth(int newWidth) {
    if (width >= MIN || width <= MAX) {
        newWidth = width;
    }
}

}// end class

BoxDriver.java

package l08;
import java.util.Scanner;


public class BoxDriver {

/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    Scanner kb = new Scanner(System.in);

    //Testing constructors, if everything is good, then nothing will be
    //printed!
    System.out.println("\n\n=========================");
    System.out.println("Testing the constructor");
    System.out.println("=========================");
    Box b1 = new Box(30,15,'*',true);
    Box b2 = new Box(-2,-2,'#',false);
    Box b3 = new Box(2,5,'*',false);
    System.out.println("\n(If nothing is printed, "
            + "there were no run-time errors!)");
    System.out.print("\nPress ENTER to continue...");
    kb.nextLine();


    //Testing the getters of the Box class
    System.out.println("\n\n=========================");
    System.out.println("Testing the getters");
    System.out.println("=========================");
    System.out.println("Box 1: width=" + b1.getWidth() 
            + " and length=" + b1.getLength() 
            + "\t\t(should be 20 and 15)");
    System.out.println("Box 2: symbol=" + b2.getSymbol()
            + " and filled=" + b2.isFilled() + "\t(should be # and false)");
    System.out.println("Box 3: width=" + b3.getWidth() 
            + " and length=" + b3.getLength() + "\t\t(should be 3 and 5)");
    System.out.print("\nPress ENTER to continue...");
    kb.nextLine();


    //Testing the setters of the Box class
    System.out.println("\n\n=========================");
    System.out.println("Testing the setters");
    System.out.println("=========================");
    b1.setFilled(false);//changing it to non-filled box
    b1.setWidth(500);
    b1.setLength(14);
    b1.setSymbol('A');
    System.out.println("Box 1: width=" + b1.getWidth() 
            + " and length=" + b1.getLength() + " "
            + "symbol=" + b1.getSymbol()
            + " filled=" + b1.isFilled()
            + "\n(should now be changed to 20, 14, A, and false)");

    b2.setFilled(true);//changing it to non-filled box
    b2.setWidth(2);
    b2.setLength(2);
    System.out.println("\nBox 2: width=" + b2.getWidth() 
            + " and length=" + b2.getLength() + " "
            + "symbol=" + b2.getSymbol()
            + " filled=" + b2.isFilled()
            + "\n(should now be changed to 3, 3, #, and true)");
    System.out.print("\nPress ENTER to continue...");
    kb.nextLine();


    //Testing drawBox() method
    System.out.println("\n\n=========================");
    System.out.println("Testing drawBox() method");
    System.out.println("=========================");
    System.out.println("Drawing box #1 (" + b1.getWidth() + "x"
            + b1.getLength() + ", not filled)");
    b1.drawBox();
    System.out.print("\nPress ENTER to continue...");
    kb.nextLine();

    System.out.println("\n\nDrawing box #2 (" + b2.getWidth() + "x"
            + b2.getLength() + ", filled)");
    b2.drawBox();
    System.out.print("\nPress ENTER to continue...");
    kb.nextLine();

    System.out.println("\n\nDrawing box #3 (" + b3.getWidth() + "x"
            + b3.getLength() + ", not filled)");
    b3.drawBox();
    System.out.print("\nPress ENTER to continue...");
    kb.nextLine();

}//end main()

}//end class

box2 的长度应该设置为 3，因为它是 2，但它不起作用？我真的不知道为什么。

输出

=========================
Testing the constructor
=========================

(If nothing is printed, there were no run-time errors!)

Press ENTER to continue...


=========================
Testing the getters
=========================
Box 1: width=20 and length=15       (should be 20 and 15)
Box 2: symbol=# and filled=false    (should be # and false)
Box 3: width=3 and length=5     (should be 3 and 5)

Press ENTER to continue...


=========================
Testing the setters
=========================
Box 1: width=20 and length=14 symbol=A filled=false
(should now be changed to 20, 14, A, and false)

Box 2: width=3 and length=2 symbol=# filled=true
(should now be changed to 3, 3, #, and true)

标签： javagetter-setter

解决方案

setLength您在and中有相同的错误setWidth（只是变量名称不同）；也就是说，您已经测试了现有length（或width）属性而不是新值。此外，您需要一个逻辑与。改变，

public void setLength(int newLength) {
    if (length >= MIN || length <= MAX) {
        length = newLength;
    }
}

到

public void setLength(int newLength) {
    if (newLength >= MIN && newLength <= MAX) {
        length = newLength;
    }
}

和改变

public void setWidth(int newWidth) {
    if (width >= MIN || width <= MAX) {
        newWidth = width;
    }
}

也真的要更新width了……

public void setWidth(int newWidth) {
    if (newWidth >= MIN && newWidth <= MAX) {
        width = newWidth;
    }
}

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