VersionMessage: move parse() to static constructor read()

core/src/main/java/org/bitcoinj/core/BitcoinSerializer.java

@@ -217,7 +217,7 @@ public class BitcoinSerializer extends MessageSerializer {
         ByteBuffer payload = ByteBuffer.wrap(payloadBytes);
         // We use an if ladder rather than reflection because reflection is very slow on Android.
         if (command.equals("version")) {
-            return new VersionMessage(payload);
+            return VersionMessage.read(payload);
         } else if (command.equals("inv")) { 
             return makeInventoryMessage(payload);
         } else if (command.equals("block")) {

core/src/main/java/org/bitcoinj/core/VersionMessage.java

@@ -92,8 +92,38 @@ public class VersionMessage extends BaseMessage {
 
     private static int NETADDR_BYTES = Services.BYTES + /* IPv6 */  16 + /* port */ Short.BYTES;
 
-    public VersionMessage(ByteBuffer payload) throws ProtocolException {
+    /**
-        super(payload);
+     * Deserialize this message from a given payload.
+     *
+     * @param payload payload to deserialize from
+     * @return read message
+     * @throws BufferUnderflowException if the read message extends beyond the remaining bytes of the payload
+     */
+    public static VersionMessage read(ByteBuffer payload) throws BufferUnderflowException, ProtocolException {
+        int clientVersion = (int) ByteUtils.readUint32(payload);
+        check(clientVersion >= ProtocolVersion.MINIMUM.intValue(),
+                ProtocolException::new);
+        Services localServices = Services.read(payload);
+        Instant time = Instant.ofEpochSecond(ByteUtils.readInt64(payload));
+        Services receivingServices = Services.read(payload);
+        InetAddress receivingInetAddress = PeerAddress.getByAddress(Buffers.readBytes(payload, 16));
+        int receivingPort = ByteUtils.readUint16BE(payload);
+        InetSocketAddress receivingAddr = new InetSocketAddress(receivingInetAddress, receivingPort);
+        Buffers.skipBytes(payload, NETADDR_BYTES); // addr_from
+        // uint64 localHostNonce (random data)
+        // We don't care about the localhost nonce. It's used to detect connecting back to yourself in cases where
+        // there are NATs and proxies in the way. However we don't listen for inbound connections so it's
+        // irrelevant.
+        Buffers.skipBytes(payload, 8);
+        // string subVer (currently "")
+        String subVer = Buffers.readLengthPrefixedString(payload);
+        // int bestHeight (size of known block chain).
+        long bestHeight = ByteUtils.readUint32(payload);
+        boolean relayTxesBeforeFilter = clientVersion >= ProtocolVersion.BLOOM_FILTER.intValue() ?
+                payload.get() != 0 :
+                true;
+        return new VersionMessage(clientVersion, localServices, time, receivingServices, receivingAddr, subVer,
+                bestHeight, relayTxesBeforeFilter);
     }
 
     /**
@@ -147,29 +177,7 @@ public class VersionMessage extends BaseMessage {
 
     @Override
     protected void parse(ByteBuffer payload) throws BufferUnderflowException, ProtocolException {
-        clientVersion = (int) ByteUtils.readUint32(payload);
+        throw new UnsupportedOperationException();
-        check(clientVersion >= ProtocolVersion.MINIMUM.intValue(),
-                ProtocolException::new);
-        localServices = Services.read(payload);
-        time = Instant.ofEpochSecond(ByteUtils.readInt64(payload));
-        receivingServices = Services.read(payload);
-        InetAddress receivingInetAddress = PeerAddress.getByAddress(Buffers.readBytes(payload, 16));
-        int receivingPort = ByteUtils.readUint16BE(payload);
-        receivingAddr = new InetSocketAddress(receivingInetAddress, receivingPort);
-        Buffers.skipBytes(payload, NETADDR_BYTES); // addr_from
-        // uint64 localHostNonce (random data)
-        // We don't care about the localhost nonce. It's used to detect connecting back to yourself in cases where
-        // there are NATs and proxies in the way. However we don't listen for inbound connections so it's
-        // irrelevant.
-        Buffers.skipBytes(payload, 8);
-        // string subVer (currently "")
-        subVer = Buffers.readLengthPrefixedString(payload);
-        // int bestHeight (size of known block chain).
-        bestHeight = ByteUtils.readUint32(payload);
-        relayTxesBeforeFilter =
-                clientVersion >= ProtocolVersion.BLOOM_FILTER.intValue() ?
-                payload.get() != 0 :
-                true;
     }
 
     @Override

core/src/test/java/org/bitcoinj/core/VersionMessageTest.java

@@ -37,7 +37,7 @@ public class VersionMessageTest {
     public void decode_noRelay_bestHeight_subVer() {
         // Test that we can decode version messages which miss data which some old nodes may not include
         String hex = "7111010000000000000000003334a85500000000000000000000000000000000000000000000ffff7f000001479d000000000000000000000000000000000000ffff7f000001479d00000000000000000f2f626974636f696e6a3a302e31332f0004000000";
-        VersionMessage ver = new VersionMessage(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
+        VersionMessage ver = VersionMessage.read(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
         assertFalse(ver.relayTxesBeforeFilter);
         assertEquals(1024, ver.bestHeight);
         assertEquals("/bitcoinj:0.13/", ver.subVer);
@@ -46,7 +46,7 @@ public class VersionMessageTest {
     @Test
     public void decode_relay_bestHeight_subVer() {
         String hex = "711101000000000000000000a634a85500000000000000000000000000000000000000000000ffff7f000001479d000000000000000000000000000000000000ffff7f000001479d00000000000000000f2f626974636f696e6a3a302e31332f0004000001";
-        VersionMessage ver = new VersionMessage(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
+        VersionMessage ver = VersionMessage.read(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
         assertTrue(ver.relayTxesBeforeFilter);
         assertEquals(1024, ver.bestHeight);
         assertEquals("/bitcoinj:0.13/", ver.subVer);
@@ -55,7 +55,7 @@ public class VersionMessageTest {
     @Test
     public void decode_relay_noBestHeight_subVer() {
         String hex = "711101000000000000000000c334a85500000000000000000000000000000000000000000000ffff7f000001479d000000000000000000000000000000000000ffff7f000001479d00000000000000000f2f626974636f696e6a3a302e31332f0000000001";
-        VersionMessage ver = new VersionMessage(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
+        VersionMessage ver = VersionMessage.read(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
         assertTrue(ver.relayTxesBeforeFilter);
         assertEquals(0, ver.bestHeight);
         assertEquals("/bitcoinj:0.13/", ver.subVer);
@@ -64,7 +64,7 @@ public class VersionMessageTest {
     @Test(expected = ProtocolException.class)
     public void decode_relay_noBestHeight_noSubVer() {
         String hex = "00000000000000000000000048e5e95000000000000000000000000000000000000000000000ffff7f000001479d000000000000000000000000000000000000ffff7f000001479d0000000000000000";
-        VersionMessage ver = new VersionMessage(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
+        VersionMessage ver = VersionMessage.read(ByteBuffer.wrap(ByteUtils.parseHex(hex)));
     }
 
     @Test
@@ -75,7 +75,7 @@ public class VersionMessageTest {
         ver.localServices = Services.of(1);
         ver.receivingAddr = new InetSocketAddress(InetAddress.getByName("4.3.2.1"), 8333);
         byte[] serialized = ver.bitcoinSerialize();
-        VersionMessage ver2 = new VersionMessage(ByteBuffer.wrap(serialized));
+        VersionMessage ver2 = VersionMessage.read(ByteBuffer.wrap(serialized));
         assertEquals(1234, ver2.bestHeight);
         assertEquals(Instant.ofEpochSecond(23456), ver2.time);
         assertEquals("/bitcoinj/", ver2.subVer);
@@ -93,7 +93,7 @@ public class VersionMessageTest {
         ver.localServices = Services.of(1);
         ver.receivingAddr = new InetSocketAddress(InetAddress.getByName("2002:db8:85a3:0:0:8a2e:370:7335"), 8333);
         byte[] serialized = ver.bitcoinSerialize();
-        VersionMessage ver2 = new VersionMessage(ByteBuffer.wrap(serialized));
+        VersionMessage ver2 = VersionMessage.read(ByteBuffer.wrap(serialized));
         assertEquals(1234, ver2.bestHeight);
         assertEquals(Instant.ofEpochSecond(23456), ver2.time);
         assertEquals("/bitcoinj/", ver2.subVer);