Add a wallet dumping tool, toString() on the Wallet object.

src/com/google/bitcoin/core/Wallet.java

@@ -347,4 +347,26 @@ public class Wallet implements Serializable {
         }
         return balance;
     }
+
+    @Override
+    public String toString() {
+        StringBuilder builder = new StringBuilder();
+        builder.append("Wallet containing ");
+        builder.append(Utils.bitcoinValueToFriendlyString(getBalance()));
+        builder.append("BTC in ");
+        builder.append(unspent.size());
+        builder.append(" unspent transactions/");
+        builder.append(fullySpent.size());
+        builder.append(" spent transactions");
+        // Do the keys.
+        builder.append("\nKeys:\n");
+        for (ECKey key : keychain) {
+            builder.append("  addr:");
+            builder.append(key.toAddress(params));
+            builder.append(" ");
+            builder.append(key.toString());
+            builder.append("\n");
+        }
+        return builder.toString();
+    }
 }

src/com/google/bitcoin/examples/DumpWallet.java

@@ -0,0 +1,36 @@
+/**
+ * Copyright 2011 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.examples;
+
+import com.google.bitcoin.core.Wallet;
+
+import java.io.File;
+
+/**
+ * DumpWallet loads a serialized wallet and prints information about what it contains.
+ */
+public class DumpWallet {
+    public static void main(String[] args) throws Exception {
+        if (args.length != 1) {
+            System.out.println("Usage: java com.google.bitcoin.examples.DumpWallet <filename>");
+            return;
+        }
+
+        Wallet wallet = Wallet.loadFromFile(new File(args[0]));
+        System.out.println(wallet.toString());
+    }
+}