一、需求背景
需要给一份问卷进行授权，授权的角色固定为4类，分别是： 农户、企业、金融机构、政府用户，这4类角色定义在字典里面，并且很少改动。这4类角色下面，可能有多个角色，这些角色通过字典的key关联到上述4个类型中的一个;
在新增、编辑问卷的时候，需要把这4类所有的角色都展示出来，供管理员选择。
二、需求分析
由于涉及到的数据很少改动，且主要以查询为主，于是第一想法就是通过 枚举+链对实现,具体实现如下:
三、实现过程
1. 枚举类
import lombok.Getter;
import lombok.Setter;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.function.Consumer;
import java.util.stream.Stream;
import static com.xxx.xxx.utils.StreamUtil.forEachIfPresent;
/**
* Author: wxz
* Date: 2023.11.29 10:35
* Description: 问卷调查授权枚举
*/
public enum PaperAuthorRoleEnum {
ANONYMITY("un-limit", "不限", Collections.singletonList("")),
AGRICULTURAL("member", "农户",Collections.singletonList("member")),
ENTERPRISE("enterprises", "企业", Collections.singletonList("agricultural-enterprises")),
FINANCIAL_INSTITUTION("finance", "金融机构",FinanceRoleKeys()),
GOVERNMENT_USERS("government", "政府用户", GovernmentRoleKeys()),
;
/**
* 角色类型
*/
@Getter
private final String type;
/**
* 角色类型名称
*/
@Getter
private final String typeName;
/**
* 角色id集合
*/
@Getter
private final List<String> roleKeys;
/**
* 角色列表
*/
@Getter
private final List<PaperRole> paperRoleList;
/**
* 角色缓存数据
*/
private static Map<String, SysRole> roleCache = new ConcurrentHashMap<>();
PaperAuthorRoleEnum(String type, String typeName, List<String> roleKeys) {
this.type = type;
this.typeName = typeName;
this.roleKeys = roleKeys;
this.paperRoleList = getRolesFromCache(roleKeys);
}
/**
* 根据角色类型查找枚举
* @param type 角色类型
* @return 类型枚举
*/
public static PaperAuthorRoleEnum of(String type) {
if (type == null) {
return null;
}
PaperAuthorRoleEnum[] values = PaperAuthorRoleEnum.values();
for (PaperAuthorRoleEnum a : values) {
if (a.type.equals(type)) {
return a;
}
}
return null;
}
/**
* 金融机构角色keys
*/
private static List<String> FinanceRoleKeys() {
List<String> list = new ArrayList<>();
//银行机构有5个等级
for (int i = 1; i < 5; i++) {
list.add("bank_level_" + i);
}
return list;
}
/**
* 政府角色keys
*/
private static List<String> GovernmentRoleKeys() {
return new ArrayList<>(Arrays.asList("collector","government","government-role"));
}
/**
* 获取所有枚举的keys
* @return
*/
private List<String> getAllRolKeys() {
List<String> roleKeys = new ArrayList<>();
roleKeys.addAll(Collections.singletonList("member"));
roleKeys.addAll(Collections.singletonList("agricultural-enterprises"));
roleKeys.addAll(FinanceRoleKeys());
roleKeys.addAll(GovernmentRoleKeys());
return roleKeys;
}
/**
* 从缓存中获取角色列表
* @param roleKeys
* @return
*/
private List<PaperRole> getRolesFromCache(List<String> roleKeys) {
List<PaperRole> paperRoles = new ArrayList<>();
Set<String> notExitKeys = new HashSet<>();
boolean sign = (roleCache == null);
//如果已经存在缓存里面,则优先从缓存里面获取
if (sign) {
notExitKeys.addAll(getAllRolKeys());
roleCache = new ConcurrentHashMap<>();
} else {
roleKeys.forEach(key -> {
if (!roleCache.containsKey(key)) {
notExitKeys.add(key);
} else {
PaperRole paperRole =
new PaperRole().setRoleId(roleCache.get(key).getRoleId()).setRoleName(roleCache.get(key).getRoleName());
paperRoles.add(paperRole);
}
});
}
//不存在于缓存的数据,重新从数据库里面查询出来,放在缓存里面
if (notExitKeys.size() > 0) {
Optional<List<SysRole>> sysRoles =
Optional.ofNullable(SpringUtils.getBean(SysRoleMapper.class).selectListByRoleKeys(new ArrayList<>(notExitKeys)));
// forEachIfPresent()方法参考: https://blog.csdn.net/qq_37844454/article/details/134964619
forEachIfPresent(sysRoles,item->{
roleCache.put(item.getRoleKey(), item);
PaperRole paperRole = new PaperRole().setRoleId(item.getRoleId()).setRoleName(item.getRoleName());
paperRoles.add(paperRole);
});
}
return paperRoles;
}
/**
* 获取所有的枚举
*/
public static PaperAuthorRoleEnum[] getValues() {
return new PaperAuthorRoleEnum[]{
AGRICULTURAL, ENTERPRISE, FINANCIAL_INSTITUTION, GOVERNMENT_USERS};
}
}
2. 控制器调用
//使用线程安装的链对做缓存,避免读多写少的数据频繁请求数据库
private static ConcurrentLinkedQueue<PaperAuthorTypeDTO> dtoQueue = new ConcurrentLinkedQueue<>();
@GetMapping(value = "/getRoleList")
public AjaxResult getRoleList() {
if (CollectionUtils.isEmpty(dtoQueue)) {
dtoQueue = new ConcurrentLinkedQueue<>();
Arrays.stream(PaperAuthorRoleEnum.getValues()).forEach(anEnum->{
dtoQueue.offer(new PaperAuthorTypeDTO().setRoleId(anEnum.getType()).setRoleName(anEnum.getTypeName()));
});
}
return AjaxResult.success(dtoQueue);
}
