Remove dead code that was used for appearsIn -> appearsInHashes migration, which pre-dates protobuf wallets. Make a few package-private members fully private.

core/src/main/java/com/google/bitcoin/core/Transaction.java

@@ -57,30 +57,25 @@ public class Transaction extends ChildMessage implements Serializable {
 
     private long lockTime;
 
-    // This is being migrated to appearsInHashes. It's set to null after migration.
+    // This is either the time the transaction was broadcast as measured from the local clock, or the time from the
-    Set<StoredBlock> appearsIn;
+    // block in which it was included. Note that this can be changed by re-orgs so the wallet may update this field.
-    
+    // Old serialized transactions don't have this field, thus null is valid. It is used for returning an ordered
-    // Stored only in Java serialization. This is either the time the transaction was broadcast as measured from the
+    // list of transactions from a wallet, which is helpful for presenting to users.
-    // local clock, or the time from the block in which it was included. Note that this can be changed by re-orgs so
+    private Date updatedAt;
-    // the wallet may update this field. Old serialized transactions don't have this field, thus null is valid.
-    // It is used for returning an ordered list of transactions from a wallet, which is helpful for presenting to
-    // users.
-    Date updatedAt;
 
     // This is an in memory helper only.
-    transient Sha256Hash hash;
+    private transient Sha256Hash hash;
     
     // Data about how confirmed this tx is. Serialized, may be null. 
     private TransactionConfidence confidence;
 
-    // This records which blocks the transaction
+    // This records which blocks the transaction has been included in. For most transactions this set will have a
-    // has been included in. For most transactions this set will have a single member. In the case of a chain split a
+    // single member. In the case of a chain split a transaction may appear in multiple blocks but only one of them
-    // transaction may appear in multiple blocks but only one of them is part of the best chain. It's not valid to
+    // is part of the best chain. It's not valid to have an identical transaction appear in two blocks in the same chain
-    // have an identical transaction appear in two blocks in the same chain but this invariant is expensive to check,
+    // but this invariant is expensive to check, so it's not directly enforced anywhere.
-    // so it's not directly enforced anywhere.
     //
     // If this transaction is not stored in the wallet, appearsInHashes is null.
-    Set<Sha256Hash> appearsInHashes;
+    private Set<Sha256Hash> appearsInHashes;
 
     public Transaction(NetworkParameters params) {
         super(params);
@@ -218,18 +213,6 @@ public class Transaction extends ChildMessage implements Serializable {
      * because it's not stored in the wallet or because it has never appeared in a block.
      */
     public Collection<Sha256Hash> getAppearsInHashes() {
-        if (appearsInHashes != null)
-            return appearsInHashes;
-        
-        if (appearsIn != null) {
-            log.info("Migrating a tx to appearsInHashes");
-            appearsInHashes = new HashSet<Sha256Hash>(appearsIn.size());
-            for (StoredBlock block : appearsIn) {
-                appearsInHashes.add(block.getHeader().getHash());
-            }
-            appearsIn = null;
-        }
-        
         return appearsInHashes;
     }
 

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

@@ -1028,7 +1028,7 @@ public class Wallet implements Serializable {
         checkArgument(!pending.containsKey(tx.getHash()), "commitTx called on the same transaction twice");
         log.info("commitTx of {}", tx.getHashAsString());
         BigInteger balance = getBalance();
-        tx.updatedAt = Utils.now();
+        tx.setUpdateTime(Utils.now());
         // Mark the outputs we're spending as spent so we won't try and use them in future creations. This will also
         // move any transactions that are now fully spent to the spent map so we can skip them when creating future
         // spends.

core/src/test/java/com/google/bitcoin/core/WalletTest.java

@@ -26,7 +26,6 @@ import org.junit.Test;
 
 import java.io.File;
 import java.math.BigInteger;
-import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.concurrent.CountDownLatch;
@@ -616,8 +615,8 @@ public class WalletTest {
 
         // Verify we can handle the case of older wallets in which the timestamp is null (guessed from the
         // block appearances list).
-        tx1.updatedAt = null;
+        tx1.setUpdateTime(null);
-        tx3.updatedAt = null;
+        tx3.setUpdateTime(null);
         // Check we got them back in order.
         transactions = wallet.getTransactionsByTime();
         assertEquals(tx2,  transactions.get(0));
@@ -637,18 +636,6 @@ public class WalletTest {
         wallet.addKey(new ECKey());
         assertEquals(now + 60, wallet.getEarliestKeyCreationTime());
     }
-    
-    @Test
-    public void transactionAppearsInMigration() throws Exception {
-        // Test migration from appearsIn to appearsInHashes
-        Transaction tx1 = createFakeTx(params, Utils.toNanoCoins(1, 0), myAddress);
-        StoredBlock b1 = createFakeBlock(params, blockStore, tx1).storedBlock;
-        tx1.appearsIn = new HashSet<StoredBlock>();
-        tx1.appearsIn.add(b1);
-        assertEquals(1, tx1.getAppearsInHashes().size());
-        assertTrue(tx1.getAppearsInHashes().contains(b1.getHeader().getHash()));
-        assertNull(tx1.appearsIn);
-    }
 
     @Test
     public void spendToSameWallet() throws Exception {