如何为 java 类创建 HarnessTest 类？

Question

我已经为我的应用程序创建了基本类。我正在尝试在 TestHarness 构造函数下为我的两个类运行手动单元测试，但遇到错误： 类中的构造函数 Person 不能应用于给定类型 必需：无参数 找到：字符串，字符串，整数 原因：实际参数列表和形式参数列表的长度不同

和

找不到符号 符号：方法 setLastName(String) 位置：Person 类型的变量 p1

这是我的 Person.java 类：

public class Person {
    private String firstName, lastName;
    private Integer age;



    public Person (String firstName, String lastName, Integer age) {
        this.firstName = firstName;
        if (firstName == "" || firstName == null)
            this.firstName = "No first name given";



        this.lastName = lastName;
        if (lastName == "" || lastName == null)
            this.lastName = "No last name given";


        this.age = age; 


    }

    public String getFirstName () {
        return firstName;
    }

    public void setFirstName (String firstName) {
        if (firstName == "" || firstName == null)
            this.firstName = "No first name given";
        else
            this.firstName = firstName;
    }

    public String getLastName () {
        return lastName;
    }

    public void setLastName (String lastName) {
        if (lastName == "" || lastName == null)
            this.lastName = "No last name given";
        else
            this.lastName = lastName;
    }

    public Integer getAge () {
        return age;
    }

    public void setAge (Integer age) {
            this.age = age;
    }

    @Override
    public String toString() {
    return "First Name: "+firstName + "\nLast Name : " + lastName +
            "\nAge: " + ((age<=0 || age>=120)? "No age given" : age); 
}
}

这是我的 Case.java 类：

public class Case {
     private String caseID ="" ;


public Case (String newCaseID) {
    this.caseID  = newCaseID; 
    if (caseID == "" || caseID == null)
            this.caseID = "No case ID given";
        else
            this.caseID = caseID;
}

public String getCaseID () {
    return caseID;
}

public void setCaseID (String newCaseID) {
    if (caseID == "" || caseID == null)
            this.caseID = "No case ID given";
        else
            this.caseID = caseID; 
}


@Override
public String toString() {
return "Case ID: "+ caseID;
        }
}

这是我的 TestHarness.java 类：

package HHHN;
/**
 *
 * @author 18057
 */

public class TestHarness {

    public TestHarness () {
    //Person test cases
    //Test 1 - valid first name
    Person p1 = new Person("","Smith",14);
    System.out.print("Person information: " + p1.toString());
    //change first name
    p1.setFirstName("Laura");
    System.out.println(p1.toString());


    //Test 2 - valid last name
    Person p2 = new Person("Laura","",14);
    System.out.print("Person information: " + p2.toString());
    //change last name
    p2.setLastName("Smith");
    System.out.println(p2.toString());

    //Test 3 - valid age
    Person p3 = new Person("Laura","Smith",0);
    System.out.print("Person information: " + p3.toString());
    //change age
    p3.setAge(14);
    System.out.println(p3.toString());



    //Case test cases
    //Test 1 - valid caseID
    Case c1 = new Case("");
    System.out.println("Missing person case ID: "+c1.toString());
    //change case ID
    c1.setCaseID("V1234");
    System.out.print(c1.toString());

}
}

任何帮助将不胜感激。

如果需要任何其他信息，请告诉我。

Answer 1

您的代码中有一些错误。我们可以从您的“TestHarness”课程开始：

Person p1 = new Person("", "Smith", 14);

你不能有重复的变量，所以第一个之后的每个 p1 必须有不同的名称（p2？）或者你可以像这样再次重用变量：

p1 = new Person("Laura", "", 14);

接下来，我们将代码放在您的“Person”类中。它不会导致错误，但毫无意义：

this.firstName = firstName;
    if (firstName == "" || firstName == null)
        this.firstName = "No first name given";
    else
        this.firstName = firstName;

可以改为：

this.firstName = firstName;
if (firstName == "" || firstName == null)
    this.firstName = "No first name given";

由于您已经设置了变量，因此您不需要为 else 情况再次设置它。

转到年龄，您不能将整数设置为字符串，因此您将无法像以前那样使该变量等于“未指定年龄”。相反，您可以更改 toString 方法以在其中包含 if 语句。

@Override
public String toString() {
    return "First Name: "+firstName + "\nLast Name : " + lastName +
        "\nAge: " + ((age <=0  || age >= 120 )? "No age given" : age); 
}

然后，当您设置年龄时，不要费心检查它是否在范围内，只需将其设置为给定的任何整数值即可。您的错误来自：

this.age = age; 
    if (age <=0  || age >= 120 )
        this.age = "No age given";    //<--- ERROR
    else
        this.age = age;

因为您不能将整数设置为字符串。希望这会有所帮助。