如何使用字符串访问实例中的java类成员
如何使用字符串访问实例中的java类成员
提问于 2019-07-23 01:49:49
我有一个包含一些数据的小类，叫做MyData
public class MyData {
public String name = "";
public String nameonly = "";
public int id = 0;
public double earn = 0;
public double paid = 0;
....
public MyData(String name, String nameonly, int id) {
this.name = name;
this.nameonly = nameonly;
this.id = id;
}
}然后我有一个包含这个类的数组的类，用于特定类型的人，名为AllMyData
public class AllMyData {
public ArrayList<MyData> cli = new ArrayList<>();
public ArrayList<MyData> sub = new ArrayList<>();
public ArrayList<MyData> emp = new ArrayList<>();
public ArrayList<MyData> exp = new ArrayList<>();
public ArrayList<MyData> oex = new ArrayList<>();
public ArrayList<MyData> bin = new ArrayList<>();
public ArrayList<MyData> ven = new ArrayList<>();
....
}在main类中，我需要向特定的数组添加新项(如果id不存在)，其中我有一个代表AllMyData数组的字符串
public AllMyData elems = new AllMyData();
public void initArray(int id, String name, String tip) {
//this is an example just for "cli" element and "cli" is in String tip
if (!checkForId(elems.cli, id)) {
MyData element = new MyData(name, name, id);
elems.cli.add(element);
}
}
private boolean checkForId(ArrayList<MyData> a, int id) {
for (MyData e : a) {
if (e.id == id) return true;
}
return false;
}然后我只需要一个电话，例如：
initArray(5, "Test", "emp");并希望避免使用switch语句，并为每个类型重复编写代码。在此调用中，"emp“将是元素elems.emp
有没有一种方法可以用字符串名称而不是创建switch语句来访问elems成员？
回答 2
Stack Overflow用户
回答已采纳
发布于 2019-07-23 02:04:43
改为在AllMyData中创建列表映射。
import java.util.Arrays;
public class Main {
public static void main(String[] args) {
AllMyData data = new AllMyData();
data.add("foo", new MyData("Hello World", "", 1));
data.add("cli", Arrays.asList(new MyData("BASH", "", 2), new MyData("SHELL", "", 3)));
System.out.println(data);
}
}AllMyData [map={cli=[MyData [name=BASH, nameonly=, id=2, earn=0.0, paid=0.0], MyData [name=SHELL, nameonly=, id=3, earn=0.0, paid=0.0]], sub=[], oex=[], bin=[], foo=[MyData [name=Hello World, nameonly=, id=1, earn=0.0, paid=0.0]], emp=[], exp=[], ven=[]}]import java.util.*;
public class AllMyData {
private Map<String, List<MyData>> map;
public AllMyData() {
map = new HashMap<String, List<MyData>>();
map.put("cli", new ArrayList<>());
map.put("sub", new ArrayList<>());
map.put("emp", new ArrayList<>());
map.put("exp", new ArrayList<>());
map.put("oex", new ArrayList<>());
map.put("bin", new ArrayList<>());
map.put("ven", new ArrayList<>());
}
public void add(String key, List<MyData> data) {
List<MyData> list = get(key);
if (list == null) {
map.put(key, data);
} else {
list.addAll(data);
map.put(key, list);
}
}
public void add(String key, MyData data) {
List<MyData> list = get(key);
if (list == null) {
list = new ArrayList<>();
}
list.add(data);
map.put(key, list);
}
public List<MyData> get(String key) {
return map.get(key);
}
@Override
public String toString() {
return String.format("AllMyData [map=%s]", map);
}
}public class MyData {
public String name = "";
public String nameonly = "";
public int id = 0;
public double earn = 0;
public double paid = 0;
public MyData(String name, String nameonly, int id) {
this.name = name;
this.nameonly = nameonly;
this.id = id;
}
@Override
public String toString() {
return String.format("MyData [name=%s, nameonly=%s, id=%s, earn=%s, paid=%s]", name, nameonly, id, earn, paid);
}
}Stack Overflow用户
发布于 2019-07-23 02:04:50
考虑使用从字符串到ArrayList的映射。
它看起来像这样：
`Map> allMyData = new HashMap<>();`页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/57151299
复制相关文章
相似问题
腾讯云开发者
