java - 在声明后填充数组成员

Question

我的类(class)有一个数组作为它的成员之一。在构造函数内部，我想将其成员填充到以下内容中。我该怎么做，它给我一个错误。

public class GetCurrentMonth {

    Calendar now;
    String[] monthNames;

    /**
     * 
     */
    public GetCurrentMonth() {
        now = Calendar.getInstance();
        monthNames = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    }

    public String getMonth()
    {
        return monthNames[(now.get(Calendar.MONTH) + 1)];
    }
}

我不想在构造函数中添加这些月份名称，因为我想遵循良好的编码习惯，并且我被告知所有初始化都应该在构造函数中完成。

String[] monthNames = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

Answer 1

首先，在构造函数中进行初始化不仅不是好的做法，实际上不好的做法，因为:

• 你实际上必须编写一个构造函数(添加无用代码)
• 字段应该是static final 如果它们在每个实例中都相同，比如月份
• 实例字段应尽可能final，如果只有一种初始化方法，则在声明时初始化

最佳实践(包括遵守命名标准)表明您的类应如下所示:

public class GetCurrentMonth {
    private static final String[] MONTH_NAMES = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
    private final Calendar now = Calendar.getInstance();

    public String getMonth() {
        return MONTH_NAMES [(now.get(Calendar.MONTH) + 1)];
    }
}