Question

这是一个非常简单的问题。我正在为我的应用程序创建一个简单的Java对象，如下所示：

public class Category{
    // STATE
    private String mCategoryName;
    private Boolean mContainsSubcategories;
    private Subcategory[] mSubcategoryList; // Subcategory is another object
    // Constructor
    // for mContainsSubcategories == false, use the below constructor
    public Category(String categoryName, Boolean containsSubcategories){

    }
    // for mContainsSubcategories == true, use the below constructor
    public Category(String categoryName, Boolean containsSubcategories, Subcategory[] subcategoryList){

    }

    // GETTER METHODS
    /* ..................... */
}

基本上，我想要的是，根据布尔值使用不同的构造函数。如果boolean值为true，则使用一个构造函数，如果为false，则使用其他构造函数。我怎么能这样做？

Answer 1

创建一个getinstance方法：

public class Category{

    // STATE
    private String mCategoryName;
    private Boolean mContainsSubcategories;
    private Subcategory[] mSubcategoryList; // Subcategory is another object
    // Constructor
    public static Category getInstance(boolean mContainsSubcategories,String mCategoryName, Subcategory[] subcategoryList) {
        if (mContainsSubcategories){
            return new Category(mCategoryName);
        }else {
            return new Category(mCategoryName,subcategoryList);
        }
    }
    // for mContainsSubcategories == false, use the below constructor
    public Category(String categoryName){

    }
    // for mContainsSubcategories == true, use the below constructor
    public Category(String categoryName, Subcategory[] subcategoryList){

    }

    // GETTER METHODS
    /* ..................... */
}

初始化它使用：

Category myCategory =    
      Category.getInstance(mContainsSubcategories,mCategoryName,subcategoryList); 
                  //instead of new Category

根据布尔值创建2个构造函数

1 个答案: