Java:使用变量引用类变量

Question

这个问题已经有答案了:

Java: How can I access a class's field by a name stored in a variable? (2 个回答)

已关闭 5 年前。

文件Lists_of_values.java :

public class Lists_of_values {
    public static List<String> circumstances = new ArrayList<String>(Arrays.asList("Medical", "Maternity", "Bereavement", "Other"));
    public static List<String> interruptions = new ArrayList<String>(Arrays.asList("Awaiting results", "Courses not available", "Fieldwork",
            "Health reasons", "Internship with stipend", "Other"));
}

文件Main_file.java :

public String getDropdownValues(String lovs) {
    String templovList = StringUtils.join(Lists_of_values.lovs, ' ');
    return templovList;
}

这给了我:lovs cannot be resolved or is not a field

有没有办法在 getDropdownValues 中使用此上下文中的变量作为参数？这样我就可以调用 getDropdownValues("circumstances") .

Answer 1

您还可以引入一个包含基于名称的引用的 Map:

import java.util.*;

public class Lists_of_values {
    public static List<String> circumstances = Arrays.asList("Medical", "Maternity", "Bereavement", "Other");
    public static List<String> interruptions = Arrays.asList("Awaiting results", "Courses not available", "Fieldwork", "Health reasons", "Internship with stipend", "Other");

    private static Map<String, List<String>> lists = new HashMap<>();
    static {
        lists.put("circumstances", circumstances);
        lists.put("interruptions", interruptions);
    }

    public static List<String> getList(String name) {
        return lists.get(name);
    }
}

这将用作:List_of_Values.getList("circumstances")

这也会使您的代码被混淆，如果您决定使用反射，这就会中断。