Add a WalletAppKit that wraps boilerplate stuff for setting up a new app. Will convert some example apps later.

core/src/main/java/com/google/bitcoin/kits/WalletAppKit.java

@@ -0,0 +1,168 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * 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.google.bitcoin.kits;
+
+import com.google.bitcoin.core.*;
+import com.google.bitcoin.discovery.DnsDiscovery;
+import com.google.bitcoin.store.BlockStoreException;
+import com.google.bitcoin.store.SPVBlockStore;
+import com.google.bitcoin.store.WalletProtobufSerializer;
+import com.google.common.util.concurrent.AbstractIdleService;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.util.concurrent.TimeUnit;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+/**
+ * Utility class that wraps the boilerplate needed to set up a new SPV bitcoinj app. Instantiate it with a directory
+ * and file prefix, optionally configure a few things, then use start or startAndWait. The object will construct and
+ * configure a {@link BlockChain}, {@link SPVBlockStore}, {@link Wallet} and {@link PeerGroup}. Startup will be
+ * considered complete once the block chain has fully synchronized, so it can take a while. Once complete, you can
+ * go ahead and add the listeners you need to the underlying objects.
+ */
+public class WalletAppKit extends AbstractIdleService {
+    protected final String filePrefix;
+    protected final NetworkParameters params;
+    protected volatile BlockChain vChain;
+    protected volatile SPVBlockStore vStore;
+    protected volatile Wallet vWallet;
+    protected volatile PeerGroup vPeerGroup;
+    protected volatile boolean vUseAutoSave = true;
+
+    protected final File directory;
+    protected volatile File vChainFile, vWalletFile;
+
+    protected volatile InetAddress[] vPeerAddresses;
+
+    public WalletAppKit(NetworkParameters params, File directory, String filePrefix) {
+        this.params = checkNotNull(params);
+        this.directory = checkNotNull(directory);
+        this.filePrefix = checkNotNull(filePrefix);
+    }
+
+    public WalletAppKit setPeerNodes(InetAddress... addresses) {
+        checkState(state() == State.NEW, "Cannot call after startup");
+        this.vPeerAddresses = addresses;
+        return this;
+    }
+
+    public WalletAppKit setAutoSave(boolean value) {
+        checkState(state() == State.NEW, "Cannot call after startup");
+        vUseAutoSave = value;
+        return this;
+    }
+
+    @Override
+    protected void startUp() throws Exception {
+        if (!directory.exists()) {
+            if (!directory.mkdir()) {
+                throw new IOException("Could not create named directory.");
+            }
+        }
+        FileInputStream walletStream = null;
+        try {
+            vChainFile = new File(directory, filePrefix + ".spvchain");
+            vWalletFile = new File(directory, filePrefix + ".wallet");
+            boolean shouldReplayWallet = vWalletFile.exists() && !vChainFile.exists();
+            if (vWalletFile.exists()) {
+                walletStream = new FileInputStream(vWalletFile);
+                vWallet = new WalletProtobufSerializer().readWallet(walletStream);
+                if (shouldReplayWallet)
+                    vWallet.clearTransactions(0);
+            } else {
+                vWallet = new Wallet(params);
+            }
+            if (vUseAutoSave) vWallet.autosaveToFile(vWalletFile, 1, TimeUnit.SECONDS, null);
+            vStore = new SPVBlockStore(params, vChainFile);
+            vChain = new BlockChain(params, vWallet, vStore);
+            vPeerGroup = new PeerGroup(params, vChain);
+            vPeerGroup.addWallet(vWallet);
+            if (vPeerAddresses != null) {
+                for (InetAddress addr : vPeerAddresses) vPeerGroup.addAddress(addr);
+                vPeerAddresses = null;
+            } else {
+                vPeerGroup.addPeerDiscovery(new DnsDiscovery(params));
+            }
+            vPeerGroup.startAndWait();
+            vPeerGroup.downloadBlockChain();
+            // Make sure we shut down cleanly.
+            Runtime.getRuntime().addShutdownHook(new Thread() {
+                @Override public void run() {
+                    try {
+                        WalletAppKit.this.stop();
+                    } catch (Exception e) {
+                        throw new RuntimeException(e);
+                    }
+                }
+            });
+        } catch (BlockStoreException e) {
+            throw new IOException(e);
+        } finally {
+            if (walletStream != null) walletStream.close();
+        }
+    }
+
+    @Override
+    protected void shutDown() throws Exception {
+        // Runs in a separate thread.
+        try {
+            vPeerGroup.stopAndWait();
+            vWallet.saveToFile(vWalletFile);
+            vStore.close();
+
+            vPeerGroup = null;
+            vWallet = null;
+            vStore = null;
+            vChain = null;
+        } catch (BlockStoreException e) {
+            throw new IOException(e);
+        }
+    }
+
+    public NetworkParameters params() {
+        return params;
+    }
+
+    public BlockChain chain() {
+        checkState(state() == State.RUNNING, "Cannot call until startup is complete");
+        return vChain;
+    }
+
+    public SPVBlockStore store() {
+        checkState(state() == State.RUNNING, "Cannot call until startup is complete");
+        return vStore;
+    }
+
+    public Wallet wallet() {
+        checkState(state() == State.RUNNING, "Cannot call until startup is complete");
+        return vWallet;
+    }
+
+    public PeerGroup peerGroup() {
+        checkState(state() == State.RUNNING, "Cannot call until startup is complete");
+        return vPeerGroup;
+    }
+
+    public File directory() {
+        return directory;
+    }
+}