我从此开始,但是对于如何为每个DC拥有一个键,然后为该DC的计算机列表拥有多个值感到困惑,然后我还需要按环境对它们进行分组。
您忘记了一个重要的建议:枚举可能存储特定于每个枚举值的成员(方法和字段),但
static如果需要,它也可能存储成员。
您需要直接在enum类中移动按环境分组的地图:
private static final ImmutableMap<Datacenter, ImmutableList<String>> PROD_SERVERS_BY_DC;private static final ImmutableMap<Datacenter, ImmutableList<String>> STAGING_SERVERS_BY_DC;
您可以根据用户请求使用内部地图返回期望的地图:
private static final Map<Env, ImmutableMap<Datacenter, ImmutableList<String>>> SERVERS_BY_ENV;
Env另一个枚举在哪里:
public static enum Env { PROD, STAGING}在我将要提供的代码中,我将其添加为封闭类型,
Datacenter但是在其自己的文件中可能会更好,因为环境可能不是数据中心专用的概念。
最后,您使用的按环境检索服务器的方式将相关职责划分为两个类(
Datacenter枚举和当前类):
Map<Datacenter, ImmutableList<String>> machinesByDC = Utils.isProd() ? Utils.PROD_SERVERS_BY_DC : Utils.STAGING_SERVERS_BY_DC;
在枚举中引入执行此操作的方法会更好:
public static ImmutableMap<Datacenter, ImmutableList<String>> getServers(Env env){...}这将增加枚举类的凝聚力。
这是更新的枚举:
import java.util.HashMap;import java.util.Map;import com.google.common.collect.ImmutableList;import com.google.common.collect.ImmutableMap;import com.google.common.collect.ImmutableMap.Builder;public enum Datacenter { ABC(Env.PROD, "tcp://machineA:8081", "tcp://machineA:8082"), DEF(Env.PROD, "tcp://machineB:8081", "tcp://machineB:8082"), PQR(Env.PROD, "tcp://machineA:8081", "tcp://machineA:8082"), CORP(Env.STAGING, "tcp://machineC:8081", "tcp://machineC:8082"); public static enum Env { PROD, STAGING } private Env env; private String[] url; private static final ImmutableMap<Datacenter, ImmutableList<String>> PROD_SERVERS_BY_DC; private static final ImmutableMap<Datacenter, ImmutableList<String>> STAGING_SERVERS_BY_DC; private static final Map<Env, ImmutableMap<Datacenter, ImmutableList<String>>> SERVERS_BY_ENV; static { Builder<Datacenter, ImmutableList<String>> prodDataCenterBuilder = ImmutableMap.<Datacenter, ImmutableList<String>>builder(); Builder<Datacenter, ImmutableList<String>> stagingDataCenterBuilder = ImmutableMap.<Datacenter, ImmutableList<String>>builder(); for (Datacenter datacenter : Datacenter.values()) { if (datacenter.env == Env.PROD) { prodDataCenterBuilder.put(datacenter, ImmutableList.of(datacenter.url)); } else if (datacenter.env == Env.STAGING) { stagingDataCenterBuilder.put(datacenter, ImmutableList.of(datacenter.url)); } else { throw new IllegalArgumentException("not exepected env " + datacenter.env); } } PROD_SERVERS_BY_DC = prodDataCenterBuilder.build(); STAGING_SERVERS_BY_DC = stagingDataCenterBuilder.build(); SERVERS_BY_ENV = new HashMap<>(); SERVERS_BY_ENV.put(Env.PROD, PROD_SERVERS_BY_DC); SERVERS_BY_ENV.put(Env.STAGING, STAGING_SERVERS_BY_DC); } Datacenter(Env env, String... url) { this.env = env; this.url = url; } public static ImmutableMap<Datacenter, ImmutableList<String>> getServers(Env env) { ImmutableMap<Datacenter, ImmutableList<String>> map = SERVERS_BY_ENV.get(env); if (map == null) { throw new IllegalArgumentException("not exepected env " + env); } return map; }}以及如何使用它:
public static void main(String[] args) { ImmutableMap<Datacenter, ImmutableList<String>> servers = Datacenter.getServers(Env.PROD); servers.forEach((k, v) -> System.out.println("prod datacenter=" + k + ", urls=" + v)); servers = Datacenter.getServers(Env.STAGING); servers.forEach((k, v) -> System.out.println("staging datacenter=" + k + ", urls=" + v));}输出 :
产品数据中心= ABC,网址= [tcp:// machineA:8081,tcp:// machineA:8082]
产品数据中心= DEF,网址= [tcp:// machineB:8081,tcp:// machineB:8082]
产品数据中心= PQR,网址= [tcp:// machineA:8081,tcp:// machineA:8082]
登台数据中心= CORP,网址= [tcp:// machineC:8081,tcp:// machineC:8082]



