Java 如果OOP为空，如何设置位置

如果最初没有输入位置，我如何让它打印“整栋房子”字样。我认为它不起作用，因为在创建任务时，它使用的构造函数没有位置指示。有没有办法将位置从null更改为我指定的字符串

这是我的任务类：

public class Task{

    private final String choreName; 
    private final int maxCompletionInMinutes;
    private final String difficulty;
    private String location;

    public Task(String choreName, int maxCompletionInMinutes, String difficulty){
       this.choreName = choreName;
       this.maxCompletionInMinutes = maxCompletionInMinutes;
       this.difficulty = difficulty;
    }

    public Task(String choreName, int maxCompletionInMinutes, String difficulty, String location){
       this(choreName, maxCompletionInMinutes, difficulty);
       this.location = location;
    }

    public String getChoreName(){
        return choreName; 
    }    
    public int getMaxCompletionInMinutes(){
        return maxCompletionInMinutes;
    }
    public String getDifficulty(){
        return difficulty;
    }
    public String getLocation(){
        return location;
    }

    public void setLocation(String location){
        if(location == null)
        location = "Whole house";

        this.location = location;
    }

    public void prettyPrint(){
        System.out.printf("Complete the chore: %s (%s) in location: %s. This chore should take a maximum of %d minutes.%n", choreName, difficulty, location, maxCompletionInMinutes);
    }

}

这是我的驾驶课：

public class Assignment5{
    public static void main (String[] args){
        Task task1 = new Task("Dishes", 40, "Hard", "Kitchen");
        Task task2 = new Task("Dust", 45, "Hard");
        Task task3 = new Task("Vacuum", 30, "Medium");
        Task task4 = new Task("Make beds", 15, "Easy");
        Task task5 = new Task("Water plants", 15, "Easy", "Living Room");

        task1.prettyPrint();
        task2.prettyPrint();
        task3.prettyPrint();
        task4.prettyPrint();
        task5.prettyPrint();
    }

}

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我可能会改变构造器的顺序。使三参数构造函数调用四参数构造函数并提供默认值：

public Task(String choreName, int maxCompletionInMinutes, String difficulty) {
   this(choreName, maxCompletionInMinutes, difficulty, "Whole house");
}

public Task(String choreName, int maxCompletionInMinutes, String difficulty, String location) {
   this.choreName = choreName;
   this.maxCompletionInMinutes = maxCompletionInMinutes;
   this.difficulty = difficulty;
   this.location = location;
}

然后只需删除setter中的null检查逻辑

---

这也很好，因为现在您还可以将

位置

作为最后一个字段，使

任务

类不可变且线程安全

我建议使用空字符串而不是

null

来指示整个内部任务。这样做了。非常感谢！：）