runelite-client: Bypass Jagex load balancer if we can't connect

runelite-client/src/main/java/net/runelite/client/rs/ClientConfigLoader.java

@@ -29,6 +29,7 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import net.runelite.http.api.RuneLiteAPI;
+import okhttp3.HttpUrl;
 import okhttp3.Request;
 import okhttp3.Response;
 
@@ -40,10 +41,16 @@ class ClientConfigLoader
 
 	private static final String CONFIG_URL = "http://oldschool.runescape.com/jav_config.ws";
 
-	static RSConfig fetch() throws IOException
+	static RSConfig fetch(String host) throws IOException
 	{
+		HttpUrl url = HttpUrl.parse(CONFIG_URL);
+		if (host != null)
+		{
+			url = url.newBuilder().host(host).build();
+		}
+
 		final Request request = new Request.Builder()
-			.url(CONFIG_URL)
+			.url(url)
 			.build();
 
 		final RSConfig config = new RSConfig();

runelite-client/src/main/java/net/runelite/client/rs/ClientLoader.java

@@ -38,7 +38,6 @@ import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.net.URL;
 import java.security.cert.Certificate;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
@@ -58,6 +57,7 @@ import static net.runelite.client.rs.ClientUpdateCheckMode.VANILLA;
 import net.runelite.client.ui.FatalErrorDialog;
 import net.runelite.client.ui.SplashScreen;
 import net.runelite.http.api.RuneLiteAPI;
+import okhttp3.HttpUrl;
 import okhttp3.Request;
 import okhttp3.Response;
 import org.apache.commons.compress.compressors.CompressorException;
@@ -65,6 +65,8 @@ import org.apache.commons.compress.compressors.CompressorException;
 @Slf4j
 public class ClientLoader implements Supplier<Applet>
 {
+	private static final int NUM_ATTEMPTS = 6;
+
 	private ClientUpdateCheckMode updateCheckMode;
 	private Object client = null;
 
@@ -98,14 +100,42 @@ public class ClientLoader implements Supplier<Applet>
 		try
 		{
 			SplashScreen.stage(0, null, "Fetching applet viewer config");
-			RSConfig config = ClientConfigLoader.fetch();
+
+			HostSupplier hostSupplier = new HostSupplier();
+
+			String host = null;
+			RSConfig config;
+			for (int attempt = 0; ; attempt++)
+			{
+				try
+				{
+					config = ClientConfigLoader.fetch(host);
+					break;
+				}
+				catch (IOException e)
+				{
+					log.info("Failed to get jav_config from host \"{}\" ({})", host, e.getMessage());
+
+					if (attempt >= NUM_ATTEMPTS)
+					{
+						throw e;
+					}
+
+					host = hostSupplier.get();
+				}
+			}
 
 			Map<String, byte[]> zipFile = new HashMap<>();
 			{
 				Certificate[] jagexCertificateChain = getJagexCertificateChain();
 				String codebase = config.getCodeBase();
 				String initialJar = config.getInitialJar();
-				URL url = new URL(codebase + initialJar);
+				HttpUrl url = HttpUrl.parse(codebase + initialJar);
+
+				for (int attempt = 0; ; attempt++)
+				{
+					zipFile.clear();
+
 					Request request = new Request.Builder()
 						.url(url)
 						.build();
@@ -170,6 +200,19 @@ public class ClientLoader implements Supplier<Applet>
 
 							zipFile.put(metadata.getName(), buffer.toByteArray());
 						}
+						break;
+					}
+					catch (IOException e)
+					{
+						log.info("Failed to download gamepack from \"{}\" ({})", url, e.getMessage());
+
+						if (attempt >= NUM_ATTEMPTS)
+						{
+							throw e;
+						}
+
+						url = url.newBuilder().host(hostSupplier.get()).build();
+					}
 				}
 			}
 

runelite-client/src/main/java/net/runelite/client/rs/HostSupplier.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2019 Abex
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package net.runelite.client.rs;
+
+import java.io.IOException;
+import java.util.ArrayDeque;
+import java.util.Collections;
+import java.util.List;
+import java.util.Queue;
+import java.util.Random;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+import lombok.extern.slf4j.Slf4j;
+import net.runelite.http.api.worlds.WorldClient;
+
+@Slf4j
+class HostSupplier implements Supplier<String>
+{
+	private final Random random = new Random(System.nanoTime());
+	private Queue<String> hosts = new ArrayDeque<>();
+
+	@Override
+	public String get()
+	{
+		if (!hosts.isEmpty())
+		{
+			return hosts.poll();
+		}
+
+		try
+		{
+			List<String> newHosts = new WorldClient()
+				.lookupWorlds()
+				.getWorlds()
+				.stream()
+				.map(i -> i.getAddress())
+				.collect(Collectors.toList());
+
+			Collections.shuffle(newHosts, random);
+
+			hosts.addAll(newHosts.subList(0, 16));
+		}
+		catch (IOException e)
+		{
+			log.warn("Unable to retrieve world list", e);
+		}
+
+		while (hosts.size() < 2)
+		{
+			hosts.add("oldschool" + (random.nextInt(50) + 1) + ".runescape.COM");
+		}
+
+		return hosts.poll();
+	}
+}

runelite-client/src/test/java/net/runelite/client/rs/ClientConfigLoaderTest.java

@@ -37,7 +37,7 @@ public class ClientConfigLoaderTest
 	@Test
 	public void test() throws IOException
 	{
-		final RSConfig config = ClientConfigLoader.fetch();
+		final RSConfig config = ClientConfigLoader.fetch(null);
 
 		for (String key : config.getClassLoaderProperties().keySet())
 		{