与java中的point类和driver类混淆

基本上，我必须为它编写一个Point类和一个驱动程序类，这也在eclipse中完成。我遇到的问题是，当我尝试调用“pointX和pointY”变量来更改驱动程序类中的点的值时，我不断地得到一个错误。在我的指令中，变量必须在PointClass中声明为private，但是当试图在PointTest类中调用它们时会出现问题。此外，我还不清楚PointClass中的指针/get&set方法是否正确编写

为了澄清我的要求，以下是我的说明摘要：

写一个Point类。Point类应作为抽象数据类型编写

包括以下实例变量：

a。表示x坐标的整数

b。表示y坐标的整数

c。程序中的实例变量只能在Point类内部直接访问

点类有2个构造函数

a。无参数构造函数，将两个实例变量都设置为10（十）

b。具有两个参数（两个实例变量各一个）的构造函数将实例变量设置为这些参数值

包括步骤2中标识的两个实例变量的get和set方法

在Point类中包括一个toString方法

编写一个名为PointTest的客户端程序

在PointTest类中，执行以下操作

• 使用无参数构造函数创建Point类型的对象。 称之为点1
  使用two参数创建第二个Point类型的对象 构造器。这就是第二点。使用x=11，y=24的值
  调用后显示点1实例变量 点1.toString（）
  调用后显示点2实例变量 点2.toString（）
  使用x的set方法将点1的x值更改为35 点1的值
  调用后显示点1实例变量 点1.toString（）
  调用后显示点2实例变量 点2.toString（）
  使用y的set方法将点2的y值更改为13 第2点的值
  调用后显示点1实例变量 点1.toString（）
  调用后显示点2实例变量 点2.toString（）

Point类的代码如下所示

    public class PointClass {

    private int pointX;     //set instance variables
    private int pointY;


    public void setPoints() {       //method to set the points values
        pointX = 10;
        pointY = 10;

    }

    public void getPoints(int x, int y){    //method to set arguments to instance variables 
        pointX = x;
        pointY = y;
    }

    /////////////////////////////////////////////////

    public int getPointX() {
        return pointX;
    }

    public void setPointX(int x) {
        this.pointX = x;
    }

    ///////////////////////////////////////////////

    public int getPointY() {
        return pointY;
    }

    public void setPointY(int y) {
        this.pointY = y;
    }

    ///////////////////////////////////////////////

    public String toString(){   //toString method to display the values
        return "x = " + pointX + "y = " + pointY;
    }

}

import java.awt.Point;

public class PointTest{

    public static void main(String[] args){

        PointClass p = new PointClass();


        System.out.print("Lab1 Point");
        System.out.print("January 16, 2014");

        Point point1 = new Point();             //set point1 as no argument 
        Point point2 = new Point(11,24);       // set point2 as argument with x and y

        System.out.print(point1.toString());  //display point1 from toString method
        System.out.print(point2.toString()); //display point2 from toString method

        point1 = pointX(35);

        System.out.print(point1.toString());  
        System.out.print(point2.toString()); 

        point2.pointY(13);

        System.out.print(point1.toString());  
        System.out.print(point2.toString()); 
    }

}

public class PointClass {

    //Set instance variables
    private int pointX;
    private int pointY;

    //Default Constructor - Starts at (0, 0)
    public PointClass() {
        this.pointX = 0;
        this.pointY = 0;
    }

    //Constructor with specified values
    public PointClass(int x, int y){
        this.pointX = x;
        this.pointY = y;
    }

    //Setters
    public void setPointX(int x) { 
        this.pointX = x; 
    }
    public void setPointY(int y) {
        this.pointY = y;
    }

    //Getters
    public int getPointX() { 
        return this.pointX;
    }
    public int getPointY() {
        return this.pointY;
    }

    //toString for use with System.out.println()
    public String toString() {
        return "x = " + this.pointX + " y = " + this.pointY;
    }
}

驾驶员的代码如下所示

    public class PointClass {

    private int pointX;     //set instance variables
    private int pointY;


    public void setPoints() {       //method to set the points values
        pointX = 10;
        pointY = 10;

    }

    public void getPoints(int x, int y){    //method to set arguments to instance variables 
        pointX = x;
        pointY = y;
    }

    /////////////////////////////////////////////////

    public int getPointX() {
        return pointX;
    }

    public void setPointX(int x) {
        this.pointX = x;
    }

    ///////////////////////////////////////////////

    public int getPointY() {
        return pointY;
    }

    public void setPointY(int y) {
        this.pointY = y;
    }

    ///////////////////////////////////////////////

    public String toString(){   //toString method to display the values
        return "x = " + pointX + "y = " + pointY;
    }

}

import java.awt.Point;

public class PointTest{

    public static void main(String[] args){

        PointClass p = new PointClass();


        System.out.print("Lab1 Point");
        System.out.print("January 16, 2014");

        Point point1 = new Point();             //set point1 as no argument 
        Point point2 = new Point(11,24);       // set point2 as argument with x and y

        System.out.print(point1.toString());  //display point1 from toString method
        System.out.print(point2.toString()); //display point2 from toString method

        point1 = pointX(35);

        System.out.print(point1.toString());  
        System.out.print(point2.toString()); 

        point2.pointY(13);

        System.out.print(point1.toString());  
        System.out.print(point2.toString()); 
    }

}

public class PointClass {

    //Set instance variables
    private int pointX;
    private int pointY;

    //Default Constructor - Starts at (0, 0)
    public PointClass() {
        this.pointX = 0;
        this.pointY = 0;
    }

    //Constructor with specified values
    public PointClass(int x, int y){
        this.pointX = x;
        this.pointY = y;
    }

    //Setters
    public void setPointX(int x) { 
        this.pointX = x; 
    }
    public void setPointY(int y) {
        this.pointY = y;
    }

    //Getters
    public int getPointX() { 
        return this.pointX;
    }
    public int getPointY() {
        return this.pointY;
    }

    //toString for use with System.out.println()
    public String toString() {
        return "x = " + this.pointX + " y = " + this.pointY;
    }
}

编辑

好吧，在修正了一些东西之后，我仍然有点困惑，因为我仍然得到一个错误，这就是一切应该是什么样子吗

public class PointClass {

private int pointX;     //set instance variables
private int pointY;


public void setPoints() {       //method to set the points values
    pointX = 10;
    pointY = 10;

}

public PointClass(int x, int y){    //method to set arguments to instance variables 
    this.pointX = x;
    this.pointY = y;
}

/////////////////////////////////////////////////

public int getPointX() {
    return pointX;
}

public void setPointX(int x) {
    this.pointX = x;
}

///////////////////////////////////////////////

public int getPointY() {
    return pointY;
}

public void setPointY(int y) {
    this.pointY = y;
}

///////////////////////////////////////////////

public String toString(){                       //toString method to display the values
    return "x = " + pointX + "y = " + pointY;
}

}

公共类点测试{

public static void main(String[] args){


    System.out.print("Lab1 Point");
    System.out.print("January 16, 2014");

    PointClass point1 = new PointClass();         //set point1 as no argument 
    PointClass point2 = new PointClass(11, 24);  // set point2 as argument with x and y

    System.out.print(point1);  //display point1 from toString method
    System.out.print(point2); //display point2 from toString method

    point1.setPointX(35);

    System.out.print(point1);  
    System.out.print(point2); 

    point2.setPointY(13);

    System.out.print(point1);  
    System.out.print(point2); 
}

}

---

如果一个成员变量是

private

，您就不能像在这里尝试的那样在它自己的类之外直接访问它

point2.pointY(13);

必须使用编写的

public

setter/getter来完成此任务

point2.setPointY(13);

另外，在

PointClass

中有一个方法

getPoints（intx，inty）

，它实际设置变量。方法名称应更改为

setPoints（intx，inty）

此外，您还重写了

PointClass

的

toString（）

方法。因此，您不必显式调用

toString（）

编辑

public class PointTest {

    public static void main(String[] args){
        System.out.println("Lab1 Point");
        System.out.println("January 17, 2014");
        System.out.println();

        PointClass point1 = new PointClass();         //set point1 as no argument 
        PointClass point2 = new PointClass(11, 24);  // set point2 as argument with x and y

        System.out.println("Point1: " + point1);  //display point1 from toString method
        System.out.println("Point2: " + point2); //display point2 from toString method
        System.out.println();

        point1.setPointX(35);

        System.out.println("Point1: " + point1);  
        System.out.println("Point2: " + point2); 
        System.out.println();

        point2.setPointY(13);

        System.out.println("Point1: " + point1);  
        System.out.println("Point2: " + point2);
    }

}

删除

import java.awt.point；

后，需要向

PointClass

添加构造函数

public class PointClass {

private int pointX;     //set instance variables
private int pointY;

//
//This is your new constructor
//
public PointClass(int x, int y) {
    this.pointX = x;
    this.pointY = y;
}

现在您可以像这样创建此类的实例

Point point1 = new Point(11, 24); // Old way - Incorrect
PointClass point1 = new PointClass(11, 24) // Better - This will make objects of your class.

编辑#2

以下是我为你写的最后几节课：

PointClass

    public class PointClass {

    private int pointX;     //set instance variables
    private int pointY;


    public void setPoints() {       //method to set the points values
        pointX = 10;
        pointY = 10;

    }

    public void getPoints(int x, int y){    //method to set arguments to instance variables 
        pointX = x;
        pointY = y;
    }

    /////////////////////////////////////////////////

    public int getPointX() {
        return pointX;
    }

    public void setPointX(int x) {
        this.pointX = x;
    }

    ///////////////////////////////////////////////

    public int getPointY() {
        return pointY;
    }

    public void setPointY(int y) {
        this.pointY = y;
    }

    ///////////////////////////////////////////////

    public String toString(){   //toString method to display the values
        return "x = " + pointX + "y = " + pointY;
    }

}

import java.awt.Point;

public class PointTest{

    public static void main(String[] args){

        PointClass p = new PointClass();


        System.out.print("Lab1 Point");
        System.out.print("January 16, 2014");

        Point point1 = new Point();             //set point1 as no argument 
        Point point2 = new Point(11,24);       // set point2 as argument with x and y

        System.out.print(point1.toString());  //display point1 from toString method
        System.out.print(point2.toString()); //display point2 from toString method

        point1 = pointX(35);

        System.out.print(point1.toString());  
        System.out.print(point2.toString()); 

        point2.pointY(13);

        System.out.print(point1.toString());  
        System.out.print(point2.toString()); 
    }

}

public class PointClass {

    //Set instance variables
    private int pointX;
    private int pointY;

    //Default Constructor - Starts at (0, 0)
    public PointClass() {
        this.pointX = 0;
        this.pointY = 0;
    }

    //Constructor with specified values
    public PointClass(int x, int y){
        this.pointX = x;
        this.pointY = y;
    }

    //Setters
    public void setPointX(int x) { 
        this.pointX = x; 
    }
    public void setPointY(int y) {
        this.pointY = y;
    }

    //Getters
    public int getPointX() { 
        return this.pointX;
    }
    public int getPointY() {
        return this.pointY;
    }

    //toString for use with System.out.println()
    public String toString() {
        return "x = " + this.pointX + " y = " + this.pointY;
    }
}

点测试

public class PointTest {

    public static void main(String[] args){
        System.out.println("Lab1 Point");
        System.out.println("January 17, 2014");
        System.out.println();

        PointClass point1 = new PointClass();         //set point1 as no argument 
        PointClass point2 = new PointClass(11, 24);  // set point2 as argument with x and y

        System.out.println("Point1: " + point1);  //display point1 from toString method
        System.out.println("Point2: " + point2); //display point2 from toString method
        System.out.println();

        point1.setPointX(35);

        System.out.println("Point1: " + point1);  
        System.out.println("Point2: " + point2); 
        System.out.println();

        point2.setPointY(13);

        System.out.println("Point1: " + point1);  
        System.out.println("Point2: " + point2);
    }

}

当我刚刚运行这个时，我得到了这个输出

Lab1 Point
January 17, 2014

Point1: x = 0 y = 0
Point2: x = 11 y = 24

Point1: x = 35 y = 0
Point2: x = 11 y = 24

Point1: x = 35 y = 0
Point2: x = 11 y = 13

---

在您提供的代码中没有

abstract

Point

类。在您的

PointTest

类中，您正在使用/包括

java.awt.Point

，它与

PointClass

@pshemogood catch>无关！除了

getPoints（intx，inty）

使用此方法进行设置时，不应调用设置点（..）。也不需要调用

System.out.print（point1.toString（））；

只需

System.out.print（point1）

很好！

toString

将被自动调用，更重要的是，他正在导入

java.awt.Point

在尝试使用point2.setPointY时仍然会出错。方法pointX（int）类型PointTest未定义这是因为您没有使用pointclass，您的point2是java.awt.point。请尝试在pointclass中创建一个构造函数，并使用它。好的，取出java.awt.point，现在得到这两个错误，

point2=新点（11,24）的构造函数点（int，int）未定义

对于

point1=setPointX（35）；

的类型PointTest，方法setPointX（int）未定义；您需要将其更改为

PointClass（int，int）

，因为这是类的名称，并将该构造函数添加到该类中，因为您现在没有构造函数。我将更新我的答案。