Refactor the serialization logic:

- Extract serialization code out of NetworkConnection into a new class
- Created classes for Ping and VerAck messages
- Use reflection to create new message classes
- Add a few test cases to exercise the BitcoinSerializer class

Patch by Noa Resare.

tests/com/google/bitcoin/core/BitcoinSerializerTest.java

@@ -0,0 +1,64 @@
+/**
+ * Copyright 2011 Noa Resare
+ *
+ * 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.core;
+
+
+import com.google.bitcoin.bouncycastle.util.encoders.Hex;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+
+import static org.junit.Assert.assertEquals;
+
+public class BitcoinSerializerTest
+{
+    @Test
+    public void testVersion() throws Exception {
+        BitcoinSerializer bs = new BitcoinSerializer(NetworkParameters.prodNet(), false);
+        // the actual data from https://en.bitcoin.it/wiki/Protocol_specification#version
+        ByteArrayInputStream bais = new ByteArrayInputStream(Hex.decode("f9beb4d976657273696f6e0000000000550000009" +
+                "c7c00000100000000000000e615104d00000000010000000000000000000000000000000000ffff0a000001daf6010000" +
+                "000000000000000000000000000000ffff0a000002208ddd9d202c3ab457130055810100"));
+        VersionMessage vm = (VersionMessage)bs.deserialize(bais);
+        assertEquals(31900, vm.clientVersion);
+        assertEquals(1292899814L, vm.time);
+        assertEquals(98645L, vm.bestHeight);
+    }
+
+
+    @Test
+    public void testVerack() throws Exception {
+        BitcoinSerializer bs = new BitcoinSerializer(NetworkParameters.prodNet(), false);
+        // the actual data from https://en.bitcoin.it/wiki/Protocol_specification#verack
+        ByteArrayInputStream bais = new ByteArrayInputStream(Hex.decode("f9beb4d976657261636b00000000000000000000"));
+        VersionAck va = (VersionAck)bs.deserialize(bais);
+
+    }
+
+    @Test
+    public void testAddr() throws Exception {
+        BitcoinSerializer bs = new BitcoinSerializer(NetworkParameters.prodNet(), true);
+        // the actual data from https://en.bitcoin.it/wiki/Protocol_specification#addr
+        ByteArrayInputStream bais = new ByteArrayInputStream(Hex.decode("f9beb4d96164647200000000000000001f000000" +
+                "ed52399b01e215104d010000000000000000000000000000000000ffff0a000001208d"));
+        AddressMessage a = (AddressMessage)bs.deserialize(bais);
+        assertEquals(1, a.addresses.size());
+        PeerAddress pa = a.addresses.get(0);
+        assertEquals(8333, pa.port);
+        assertEquals("10.0.0.1", pa.addr.getHostAddress());
+    }
+}