Use only Java 7 features (in order to deal with #515)

libraries/launcher/org/multimc/LauncherFactory.java

@@ -5,30 +5,39 @@ import org.multimc.utils.ParamBucket;
 
 import java.util.HashMap;
 import java.util.Map;
-import java.util.function.Function;
 
 public final class LauncherFactory {
 
     private static final LauncherFactory INSTANCE = new LauncherFactory();
 
-    private final Map<String, Function<ParamBucket, Launcher>> launcherRegistry = new HashMap<>();
+    private final Map<String, LauncherProvider> launcherRegistry = new HashMap<>();
 
     private LauncherFactory() {
-        launcherRegistry.put("onesix", OneSixLauncher::new);
+        launcherRegistry.put("onesix", new LauncherProvider() {
+            @Override
+            public Launcher provide(ParamBucket parameters) {
+                return new OneSixLauncher(parameters);
+            }
+        });
     }
 
     public Launcher createLauncher(String name, ParamBucket parameters) {
-        Function<ParamBucket, Launcher> launcherCreator =
-                launcherRegistry.get(name);
+        LauncherProvider launcherProvider = launcherRegistry.get(name);
 
-        if (launcherCreator == null)
+        if (launcherProvider == null)
             throw new IllegalArgumentException("Invalid launcher type: " + name);
 
-        return launcherCreator.apply(parameters);
+        return launcherProvider.provide(parameters);
     }
 
     public static LauncherFactory getInstance() {
         return INSTANCE;
     }
 
+    public interface LauncherProvider {
+
+        Launcher provide(ParamBucket parameters);
+
+    }
+
 }

libraries/launcher/org/multimc/applet/LegacyFrame.java

@@ -141,16 +141,19 @@ public final class LegacyFrame extends Frame {
 
         @Override
         public void windowClosing(WindowEvent e) {
-            new Thread(() -> {
-                try {
-                    Thread.sleep(30000L);
-                } catch (InterruptedException localInterruptedException) {
-                    localInterruptedException.printStackTrace();
+            new Thread(new Runnable() {
+                @Override
+                public void run() {
+                    try {
+                        Thread.sleep(30000L);
+                    } catch (InterruptedException localInterruptedException) {
+                        localInterruptedException.printStackTrace();
+                    }
+
+                    LOGGER.info("Forcing exit!");
+
+                    System.exit(0);
                 }
-
-                LOGGER.info("Forcing exit!");
-
-                System.exit(0);
             }).start();
 
             if (appletWrap != null) {

libraries/launcher/org/multimc/impl/OneSixLauncher.java

@@ -58,10 +58,10 @@ public final class OneSixLauncher implements Launcher {
     public OneSixLauncher(ParamBucket params) {
         classLoader = ClassLoader.getSystemClassLoader();
 
-        mcParams = params.allSafe("param", Collections.emptyList());
+        mcParams = params.allSafe("param", Collections.<String>emptyList());
         mainClass = params.firstSafe("mainClass", "net.minecraft.client.Minecraft");
         appletClass = params.firstSafe("appletClass", "net.minecraft.client.MinecraftApplet");
-        traits = params.allSafe("traits", Collections.emptyList());
+        traits = params.allSafe("traits", Collections.<String>emptyList());
 
         userName = params.first("userName");
         sessionId = params.first("sessionId");

libraries/launcher/org/multimc/utils/ParamBucket.java

@@ -28,8 +28,15 @@ public final class ParamBucket {
     private final Map<String, List<String>> paramsMap = new HashMap<>();
 
     public void add(String key, String value) {
-        paramsMap.computeIfAbsent(key, k -> new ArrayList<>())
-                .add(value);
+        List<String> params = paramsMap.get(key);
+
+        if (params == null) {
+            params = new ArrayList<>();
+
+            paramsMap.put(key, params);
+        }
+
+        params.add(value);
     }
 
     public List<String> all(String key) throws ParameterNotFoundException {