Java tutorial
/* * Copyright 2014 http://Bither.net * * 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 net.bither.fragment.hot; import android.app.Activity; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.graphics.Typeface; import android.os.Bundle; import android.os.Handler; import android.support.v4.app.ListFragment; import android.support.v4.app.LoaderManager; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.content.AsyncTaskLoader; import android.support.v4.content.Loader; import android.text.format.DateUtils; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.TextView; import net.bither.NotificationAndroidImpl; import net.bither.R; import net.bither.bitherj.core.Peer; import net.bither.bitherj.core.PeerManager; import net.bither.bitherj.utils.Utils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import java.net.InetAddress; import java.util.Collections; import java.util.Comparator; import java.util.List; import java.util.Map; import java.util.WeakHashMap; import java.util.concurrent.RejectedExecutionException; import javax.annotation.Nonnull; public final class PeerListFragment extends ListFragment { private Activity activity; private LoaderManager loaderManager; private ArrayAdapter<Peer> adapter; private List<Peer> peerCacheList; private final Handler handler = new Handler(); private static final long REFRESH_MS = DateUtils.SECOND_IN_MILLIS; private static final int ID_PEER_LOADER = 0; private static final int ID_REVERSE_DNS_LOADER = 1; private final Map<InetAddress, String> hostnames = new WeakHashMap<InetAddress, String>(); private static final Logger log = LoggerFactory.getLogger(PeerListFragment.class); @Override public void onAttach(final Activity activity) { super.onAttach(activity); this.activity = activity; this.loaderManager = getLoaderManager(); } @Override public void onActivityCreated(final Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); } @Override public void onViewCreated(final View view, final Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); setEmptyText("No peers connected"); } @Override public void onCreate(final Bundle savedInstanceState) { super.onCreate(savedInstanceState); adapter = new ArrayAdapter<Peer>(activity, 0) { @Override public View getView(final int position, View row, final ViewGroup parent) { if (row == null) row = getLayoutInflater(null).inflate(R.layout.fragment_peer_list_row, null); final Peer peer = getItem(position); final boolean isDownloading = peer.getDownloadData(); final TextView rowIp = (TextView) row.findViewById(R.id.peer_list_row_ip); final InetAddress address = peer.getAddress().getAddr(); final String hostname = hostnames.get(address); rowIp.setText(hostname != null ? hostname : address.getHostAddress()); final TextView rowHeight = (TextView) row.findViewById(R.id.peer_list_row_height); final long bestHeight = peer.getDisplayLastBlockHeight(); rowHeight.setText(bestHeight > 0 ? bestHeight + " blocks" : null); rowHeight.setTypeface(isDownloading ? Typeface.DEFAULT_BOLD : Typeface.DEFAULT); final TextView rowVersion = (TextView) row.findViewById(R.id.peer_list_row_version); rowVersion.setText(peer.getSubVersion()); rowVersion.setTypeface(isDownloading ? Typeface.DEFAULT_BOLD : Typeface.DEFAULT); final TextView rowProtocol = (TextView) row.findViewById(R.id.peer_list_row_protocol); rowProtocol.setText("protocol: " + peer.getClientVersion()); rowProtocol.setTypeface(isDownloading ? Typeface.DEFAULT_BOLD : Typeface.DEFAULT); final TextView rowPing = (TextView) row.findViewById(R.id.peer_list_row_ping); final long pingTime = peer.pingTime; rowPing.setText( pingTime < Long.MAX_VALUE ? getString(R.string.peer_list_row_ping_time, pingTime) : null); rowPing.setTypeface(isDownloading ? Typeface.DEFAULT_BOLD : Typeface.DEFAULT); return row; } @Override public boolean isEnabled(final int position) { return false; } }; setListAdapter(adapter); loaderManager.initLoader(ID_PEER_LOADER, null, peerLoaderCallbacks); } @Override public void onResume() { super.onResume(); handler.postDelayed(new Runnable() { @Override public void run() { adapter.clear(); refreshPeer(); final Loader<String> loader = loaderManager.getLoader(ID_REVERSE_DNS_LOADER); final boolean loaderRunning = loader != null && loader.isStarted(); if (!loaderRunning) { for (int i = 0; i < adapter.getCount(); i++) { final Peer peer = adapter.getItem(i); final InetAddress address = peer.getAddress().getAddr(); if (!hostnames.containsKey(address)) { final Bundle args = new Bundle(); args.putSerializable("address", address); loaderManager.initLoader(ID_REVERSE_DNS_LOADER, args, reverseDnsLoaderCallbacks) .forceLoad(); break; } } } handler.postDelayed(this, REFRESH_MS); } }, REFRESH_MS); } @Override public void onPause() { handler.removeCallbacksAndMessages(null); super.onPause(); } @Override public void onDestroy() { loaderManager.destroyLoader(ID_REVERSE_DNS_LOADER); loaderManager.destroyLoader(ID_PEER_LOADER); super.onDestroy(); } private static class PeerLoader extends AsyncTaskLoader<List<Peer>> { private Context context; private PeerLoader(final Context context) { super(context); this.context = context.getApplicationContext(); } @Override protected void onStartLoading() { super.onStartLoading(); context.registerReceiver(broadcastReceiver, new IntentFilter(NotificationAndroidImpl.ACTION_PEER_STATE)); } @Override protected void onStopLoading() { context.unregisterReceiver(broadcastReceiver); super.onStopLoading(); } @Override public List<Peer> loadInBackground() { List<Peer> peerList = PeerManager.instance().getConnectedPeers(); return peerList; } private final BroadcastReceiver broadcastReceiver = new BroadcastReceiver() { @Override public void onReceive(final Context context, final Intent intent) { try { forceLoad(); } catch (final RejectedExecutionException x) { log.info("rejected execution: " + PeerLoader.this.toString()); } } }; } private final LoaderCallbacks<List<Peer>> peerLoaderCallbacks = new LoaderCallbacks<List<Peer>>() { @Override public Loader<List<Peer>> onCreateLoader(final int id, final Bundle args) { return new PeerLoader(activity); } @Override public void onLoadFinished(final Loader<List<Peer>> loader, final List<Peer> peers) { adapter.clear(); peerCacheList = peers; refreshPeer(); } @Override public void onLoaderReset(final Loader<List<Peer>> loader) { adapter.clear(); } }; private void refreshPeer() { if (peerCacheList != null) { Collections.sort(peerCacheList, new Comparator<Peer>() { @Override public int compare(Peer lhs, Peer rhs) { if (lhs.getClientVersion() == 0 && rhs.getClientVersion() > 0) { return 1; } if (rhs.getClientVersion() == 0 && lhs.getClientVersion() > 0) { return -1; } return -1 * Long.valueOf(Utils.parseLongFromAddress(lhs.getPeerAddress())) .compareTo(Long.valueOf(Utils.parseLongFromAddress(rhs.getPeerAddress()))); } }); for (final Peer peer : peerCacheList) { adapter.add(peer); } } } private static class ReverseDnsLoader extends AsyncTaskLoader<String> { public final InetAddress address; public ReverseDnsLoader(final Context context, @Nonnull final InetAddress address) { super(context); this.address = address; } @Override public String loadInBackground() { return address.getCanonicalHostName(); } } private final LoaderCallbacks<String> reverseDnsLoaderCallbacks = new LoaderCallbacks<String>() { @Override public Loader<String> onCreateLoader(final int id, final Bundle args) { final InetAddress address = (InetAddress) args.getSerializable("address"); return new ReverseDnsLoader(activity, address); } @Override public void onLoadFinished(final Loader<String> loader, final String hostname) { final InetAddress address = ((ReverseDnsLoader) loader).address; hostnames.put(address, hostname); loaderManager.destroyLoader(ID_REVERSE_DNS_LOADER); } @Override public void onLoaderReset(final Loader<String> loader) { } }; }