Add hosts UI

app/src/main/java/com/hippo/ehviewer/client/EhDns.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2018 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hippo.ehviewer.client;
+
+/*
+ * Created by Hippo on 2018/3/23.
+ */
+
+import android.content.Context;
+import com.hippo.ehviewer.EhApplication;
+import com.hippo.ehviewer.Hosts;
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import okhttp3.Dns;
+
+public class EhDns implements Dns {
+
+  private final Hosts hosts;
+
+  public EhDns(Context context) {
+    hosts = EhApplication.getHosts(context);
+  }
+
+  @Override
+  public List<InetAddress> lookup(String hostname) throws UnknownHostException {
+    if (hostname == null) throw new UnknownHostException("hostname == null");
+
+    InetAddress inetAddress = hosts.get(hostname);
+    if (inetAddress != null) {
+      return Collections.singletonList(inetAddress);
+    }
+
+    try {
+      return Arrays.asList(InetAddress.getAllByName(hostname));
+    } catch (NullPointerException e) {
+      UnknownHostException unknownHostException =
+          new UnknownHostException("Broken system behaviour for dns lookup of " + hostname);
+      unknownHostException.initCause(e);
+      throw unknownHostException;
+    }
+  }
+}