uuid: add cache support

build.gradle

@@ -30,6 +30,7 @@ dependencies {
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.1.0'
 
     compile group: 'com.googlecode.json-simple', name: 'json-simple', version: '1.1'
+    compile group: 'com.github.ben-manes.caffeine', name: 'caffeine', version: '2.8.6'
 }
 
 test {

src/main/java/eu/beezig/hiveapi/wrapper/HiveWrapper.java

@@ -1,12 +1,15 @@
 package eu.beezig.hiveapi.wrapper;
 
+import com.github.benmanes.caffeine.cache.AsyncCache;
+
 import java.util.concurrent.ExecutorService;
 
 public class HiveWrapper {
 
     public static String USER_AGENT;
     public static String MAXTHAT_KEY;
     public static ExecutorService ASYNC_EXECUTOR;
+    public static AsyncCache<String, String> usernameToUUIDCache;
 
     public static void setUserAgent(String userAgent) {
         USER_AGENT = userAgent;
@@ -20,6 +23,10 @@ public static void setAsyncExecutor(ExecutorService executor) {
         ASYNC_EXECUTOR = executor;
     }
 
+    public static void setUUIDCache(AsyncCache<String, String> usernameToUUIDCache) {
+        HiveWrapper.usernameToUUIDCache = usernameToUUIDCache;
+    }
+
     public static void asyncExecute(Runnable callback) {
         if(ASYNC_EXECUTOR == null) throw new RuntimeException("Async executor wasn't properly set up. Run HiveWrapper#setAsyncExecutor first.");
         ASYNC_EXECUTOR.submit(callback);

src/main/java/eu/beezig/hiveapi/wrapper/mojang/UsernameToUuid.java

@@ -1,15 +1,19 @@
 package eu.beezig.hiveapi.wrapper.mojang;
 
+import eu.beezig.hiveapi.wrapper.HiveWrapper;
 import eu.beezig.hiveapi.wrapper.utils.download.UrlBuilder;
 import eu.beezig.hiveapi.wrapper.utils.json.JObject;
 
 import java.util.concurrent.CompletableFuture;
 
 public class UsernameToUuid {
-
     public static CompletableFuture<String> getUUID(String username) {
+        if(HiveWrapper.usernameToUUIDCache == null) return loadUUID(username);
+        return HiveWrapper.usernameToUUIDCache.get(username, (k, exec) -> loadUUID(k));
+    }
+
+    private static CompletableFuture<String> loadUUID(String username) {
         CompletableFuture<JObject> responseFromMojang = JObject.get(new UrlBuilder().mojang(username).build());
         return responseFromMojang.thenApplyAsync(json -> json.getString("id"));
     }
-
 }

src/test/java/eu/beezig/hiveapi/wrapper/test/Cache.java

@@ -0,0 +1,23 @@
+package eu.beezig.hiveapi.wrapper.test;
+
+import com.github.benmanes.caffeine.cache.Caffeine;
+import eu.beezig.hiveapi.wrapper.HiveWrapper;
+import eu.beezig.hiveapi.wrapper.mojang.UsernameToUuid;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+
+import java.util.concurrent.Executors;
+
+public class Cache {
+    @BeforeAll
+    public static void setup() {
+        HiveWrapper.setAsyncExecutor(Executors.newSingleThreadExecutor());
+        HiveWrapper.setUUIDCache(Caffeine.newBuilder().buildAsync());
+    }
+
+    @Test
+    public void correctProfile() {
+        assert "069a79f444e94726a5befca90e38aaf5".equals(UsernameToUuid.getUUID("Notch").join());
+        assert HiveWrapper.usernameToUUIDCache.synchronous().getIfPresent("Notch") != null;
+    }
+}