java - 麻烦，实现main方法的Driver类

Question

我正在尝试创建一个实现 main 方法的驱动程序类。它必须创建并测试一个对象来演示所有程序功能。

我认为我已经创建了正确的驱动程序类，但我运行的测试证明我的代码中存在错误，这就是我到目前为止所拥有的。

{
public static void main(String[] args) {
    A00847872_Realtor testingPerfectMarks = new A00847872_Realtor(null, "", -2.2, "String", "String", "String", -1);

    System.out.println(testingPerfectMarks.getListingNumber());
    System.out.println(testingPerfectMarks.getAddress());
    System.out.println(testingPerfectMarks.getAskingPrice());
    System.out.println(testingPerfectMarks.getPropertyType());
    System.out.println(testingPerfectMarks.getBuildingType());
    System.out.println(testingPerfectMarks.getLandSize());
    System.out.println(testingPerfectMarks.getYearBuilt());
    System.out.println();

}}

我得到了更多我自己打印的输出

无效值

无效值

无效值

无效值

空

空

0.0

字符串

字符串

字符串

0////公开课A00847872_Realtor{ //主要字段

private String listingNumber;
private String address;
private double askingPrice; 
private String propertyType;
private String buildingType;
private String landSize;
private int yearBuilt; 

//secondary fields

private double taxes;
private int totalSquareFeet;
private int numberOfBedrooms;
private int numberOfBathrooms;
private String parkingType;

/**
 * Default constructor for creating realtor Objects
 */

public A00847872_Realtor(){

}

//constructor with paramaters for primary fields only

/**
 * Constructor for objects of class A00847872_Realtor
 * @param listingNumberParam used to set the listingNumber field
 * 
 */

public A00847872_Realtor(String listingNumberParam, String addressParam, double askingPriceParam,
String propertyTypeParam, String buildingTypeParam, String landSizeParam, int yearBuiltParam)
{

    setListingNumber(listingNumberParam);
    setAddress(addressParam);
    setAskingPrice(askingPriceParam);
    setPropertyType(propertyTypeParam);
    setBuildingType(buildingTypeParam);
    setLandSize(landSizeParam);
    setYearBuilt(yearBuiltParam);

}

//providing accessor methods. getters for primary fields
public String getListingNumber(){
    return listingNumber;
}

public String getAddress(){
    return address;
}

public double getAskingPrice(){
    return askingPrice;
}

public String getPropertyType(){
    return propertyType;
}

public String getBuildingType(){
    return buildingType;
}

public String getLandSize(){
    return landSize;
}

public int getYearBuilt(){
    return yearBuilt;
}

//accessor methods for secondary fields

public double getTaxes(){
    return taxes;
}

public int getTotalSquareFeet(){
    return totalSquareFeet;
}

public int getNumberOfBedrooms(){
    return numberOfBedrooms;
}

public int getNumberOfBathrooms(){
    return numberOfBathrooms;
}

public String getparkingType(){
    return parkingType;
}

//setters for primary fields with checks for null, empty, and negative parameters.

public void setListingNumber(String newListingNumber){

    if( newListingNumber == null || newListingNumber.isEmpty()){
        System.out.println("Invalid value");

    } else {
        listingNumber = newListingNumber;

    }

}

public void setAddress(String newAddress){

    if( newAddress == null || newAddress.isEmpty()){

        System.out.println("Invalid value");

    } else {

        address = newAddress;

    }

}

public void setAskingPrice(double price){

    if( price >= 0 ){

        askingPrice = price;

    } else {

        System.out.println("Invalid Value");

    }

}

public void setPropertyType(String newPropertyType){

    if( newPropertyType == null || newPropertyType.isEmpty()){

        System.out.println("Invalid value");

    } else {

        propertyType = newPropertyType;

    }

}

public void setBuildingType(String newBuildingType){

    if( newBuildingType == null || newBuildingType.isEmpty()){

        System.out.println("Invalid value");

    } else {

        buildingType = newBuildingType;

    }

}

public void setLandSize(String newLandSize){

    if( newLandSize == null || newLandSize.isEmpty()){

        System.out.println("Invalid value");

    } else {

        landSize = newLandSize;

    }

}

public void setYearBuilt(int newYearBuilt){

    if( newYearBuilt >= 0 ){

        yearBuilt = newYearBuilt;

    } else {

        System.out.println("Invalid Value");

    }

}

//Setters for Secondary fields

public void setTaxes(double newTaxes){ 

    if( newTaxes >= 0 ){

        taxes = newTaxes;

    } else {

        System.out.println("Invalid Value");

    }

}

public void setTotalSquareFeet(int NewTotalSquareFeet){ 

    if( NewTotalSquareFeet >= 0 ){

        totalSquareFeet = NewTotalSquareFeet;

    } else {

        System.out.println("Invalid Value");

    }

}

public void setNumberOfBedrooms(int newNumberOfBedrooms){ 

    if( newNumberOfBedrooms >= 0 ){

        numberOfBedrooms = newNumberOfBedrooms;

    } else {

        System.out.println("Invalid Value");

    }

}

public void setNumberOfBathrooms(int newNumberOfBathrooms){ 

    if( newNumberOfBathrooms >= 0 ){

        numberOfBathrooms = newNumberOfBathrooms;

    } else {

        System.out.println("Invalid Value");

    }

}

public void setParkingType(String newParkingType){ 

    if( newParkingType == null || newParkingType.isEmpty()){

        System.out.println("Invalid value");

    } else {

        parkingType = newParkingType;

    }

}

//method called printDetails() to display information in format

public void printDetails (){

    System.out.println("$" + askingPrice);
    System.out.println(address);
    System.out.println("MLS Number: " + listingNumber);
    System.out.println();
    System.out.println("Property Type: " + propertyType);
    System.out.println("Building Type: " + buildingType);
    System.out.println("Land Size: " + landSize);
    System.out.println("Built In: " + yearBuilt);
    System.out.println("Annual Taxes: " + taxes);
    System.out.println("Floor Space: " + totalSquareFeet);
    System.out.println("Bedrooms: " + numberOfBedrooms);
    System.out.println("Bathrooms: " + numberOfBathrooms);
    System.out.println("Parking Type: " + parkingType);

}

}

Answer 1

类 A00847872_Realtor 中的方法 setListingNumber 采用 String 作为参数:

public void setListingNumber(String newListingNumber){
    // ...
}

但是，在您调用该方法的类 RealtorDriver 中，您没有向其传递任何参数:

homeworkObject.setListingNumber();

您收到的错误告诉您，setListingNumber 方法需要传递一个String。因此您必须向其传递一个String。您必须自己找出并决定从哪里获取该字符串。

homeworkObject.setListingNumber("something");