convert ImmutableList to unmodifiable list

This converts all remaining instances of ImmutableList (except those
in core tests) to JDK unmodifiable list.

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

@@ -19,7 +19,6 @@ package org.bitcoinj.core;
 
 import com.google.common.annotations.*;
 import com.google.common.base.*;
-import com.google.common.collect.*;
 import org.bitcoinj.params.AbstractBitcoinNetParams;
 import org.bitcoinj.script.*;
 import org.slf4j.*;
@@ -915,10 +914,10 @@ public class Block extends Message {
         this.hash = null;
     }
 
-    /** Returns an immutable list of transactions held in this block, or null if this object represents just a header. */
+    /** Returns an unmodifiable list of transactions held in this block, or null if this object represents just a header. */
     @Nullable
     public List<Transaction> getTransactions() {
-        return transactions == null ? null : ImmutableList.copyOf(transactions);
+        return transactions == null ? null : Collections.unmodifiableList(transactions);
     }
 
     // ///////////////////////////////////////////////////////////////////////////////////////////////

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

@@ -16,32 +16,40 @@
 
 package org.bitcoinj.core;
 
-import com.google.common.collect.ImmutableList;
+import java.util.Collections;
-
 import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 /**
  * Represents Block Locator in GetBlocks and GetHeaders messages
  **/
 public final class BlockLocator {
-    private final ImmutableList<Sha256Hash> hashes;
+    private final List<Sha256Hash> hashes;  // unmodifiable list
 
     public BlockLocator() {
-        hashes = ImmutableList.of();
+        hashes = Collections.emptyList();
     }
 
     /**
      * Creates a Block locator with defined list of hashes.
      */
-    public BlockLocator(ImmutableList<Sha256Hash> hashes) {
+    public BlockLocator(List<Sha256Hash> hashes) {
-        this.hashes = hashes;
+        this.hashes = Collections.unmodifiableList(hashes);
+    }
+
+    // Create a new BlockLocator by copying an instance and appending an element
+    private BlockLocator(BlockLocator old, Sha256Hash hashToAdd) {
+        this(Stream.concat(old.hashes.stream(), Stream.of(hashToAdd))
+                .collect(Collectors.toList())
+        );
     }
 
     /**
      * Add a {@link Sha256Hash} to a newly created block locator.
      */
     public BlockLocator add(Sha256Hash hash) {
-        return new BlockLocator(new ImmutableList.Builder<Sha256Hash>().addAll(this.hashes).add(hash).build());
+        return new BlockLocator(this, hash);
     }
 
     /**

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

@@ -1247,7 +1247,7 @@ public class PeerGroup implements TransactionBroadcaster {
                 if ((chain != null && chain.shouldVerifyTransactions()) || !vBloomFilteringEnabled)
                     return;
                 // We only ever call bloomFilterMerger.calculate on jobQueue, so we cannot be calculating two filters at once.
-                FilterMerger.Result result = bloomFilterMerger.calculate(ImmutableList.copyOf(peerFilterProviders /* COW */));
+                FilterMerger.Result result = bloomFilterMerger.calculate(Collections.unmodifiableList(peerFilterProviders /* COW */));
                 boolean send;
                 switch (mode) {
                     case SEND_IF_CHANGED:

core/src/main/java/org/bitcoinj/crypto/HDPath.java

@@ -34,9 +34,9 @@ import java.util.List;
  * {@code HDPath} is immutable and uses the {@code Collections.UnmodifiableList} type internally.
  * <p>
  * It implements {@code java.util.List<ChildNumber>} to ease migration
- * from the previous Guava {@code ImmutableList<ChildNumber>}. It should be a minor breaking change
+ * from the previous implementation. When an {@code HDPath} is returned you can treat it as a {@code List<ChildNumber>}
- * to replace {@code ImmutableList<ChildNumber>} with {@code List<ChildNumber>} where necessary in your code. Although
+ * where necessary in your code. Although it is recommended to use the {@code HDPath} type for clarity and for
- * it is recommended to use the {@code HDPath} type for clarity and for access to {@code HDPath}-specific functionality.
+ * access to {@code HDPath}-specific functionality.
  * <p>
  * Take note of the overloaded factory methods {@link HDPath#M()} and {@link HDPath#m()}. These can be used to very
  * concisely create HDPath objects (especially when statically imported.)

core/src/main/java/org/bitcoinj/kits/WalletAppKit.java

@@ -17,7 +17,6 @@
 
 package org.bitcoinj.kits;
 
-import com.google.common.collect.*;
 import com.google.common.io.Closeables;
 import com.google.common.util.concurrent.AbstractIdleService;
 import org.bitcoinj.core.listeners.*;
@@ -241,7 +240,7 @@ public class WalletAppKit extends AbstractIdleService {
      * initialized/started.</p>
      */
     protected List<WalletExtension> provideWalletExtensions() throws Exception {
-        return ImmutableList.of();
+        return Collections.emptyList();
     }
 
     /**

core/src/main/java/org/bitcoinj/net/FilterMerger.java

@@ -18,10 +18,11 @@ package org.bitcoinj.net;
 
 import org.bitcoinj.core.BloomFilter;
 import org.bitcoinj.core.PeerFilterProvider;
-import com.google.common.collect.ImmutableList;
 import org.bitcoinj.core.PeerGroup;
 
+import java.util.Collections;
 import java.util.LinkedList;
+import java.util.List;
 
 // This code is unit tested by the PeerGroup tests.
 
@@ -55,7 +56,8 @@ public class FilterMerger {
         public boolean changed;
     }
 
-    public Result calculate(ImmutableList<PeerFilterProvider> providers) {
+    public Result calculate(List<PeerFilterProvider> providerList) {
+        List<PeerFilterProvider> providers = Collections.unmodifiableList(providerList);
         LinkedList<PeerFilterProvider> begunProviders = new LinkedList<>();
         try {
             // All providers must be in a consistent, unchanging state because the filter is a merged one that's

core/src/main/java/org/bitcoinj/protocols/payments/PaymentProtocol.java

@@ -22,7 +22,6 @@ import org.bitcoinj.crypto.X509Utils;
 import org.bitcoinj.script.ScriptBuilder;
 
 import com.google.common.base.MoreObjects;
-import com.google.common.collect.ImmutableList;
 import com.google.protobuf.ByteString;
 import com.google.protobuf.InvalidProtocolBufferException;
 import org.bitcoin.protocols.payments.Protos;
@@ -33,6 +32,7 @@ import java.security.*;
 import java.security.cert.*;
 import java.security.cert.Certificate;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -67,7 +67,7 @@ public class PaymentProtocol {
     public static Protos.PaymentRequest.Builder createPaymentRequest(NetworkParameters params,
             @Nullable Coin amount, Address toAddress, @Nullable String memo, @Nullable String paymentUrl,
             @Nullable byte[] merchantData) {
-        return createPaymentRequest(params, ImmutableList.of(createPayToAddressOutput(amount, toAddress)), memo,
+        return createPaymentRequest(params, Collections.singletonList(createPayToAddressOutput(amount, toAddress)), memo,
                 paymentUrl, merchantData);
     }
 
@@ -289,7 +289,7 @@ public class PaymentProtocol {
             if (refundAmount == null)
                 throw new IllegalArgumentException("Specify refund amount if refund address is specified.");
             return createPaymentMessage(transactions,
-                    ImmutableList.of(createPayToAddressOutput(refundAmount, refundAddress)), memo, merchantData);
+                    Collections.singletonList(createPayToAddressOutput(refundAmount, refundAddress)), memo, merchantData);
         } else {
             return createPaymentMessage(transactions, null, memo, merchantData);
         }

core/src/main/java/org/bitcoinj/utils/BtcAutoFormat.java

@@ -17,7 +17,6 @@
 package org.bitcoinj.utils;
 
 import static org.bitcoinj.core.Coin.SMALLEST_UNIT_EXPONENT;
-import com.google.common.collect.ImmutableList;
 
 import java.math.BigInteger;
 import static java.math.BigDecimal.ONE;
@@ -29,6 +28,7 @@ import java.text.DecimalFormat;
 import java.text.DecimalFormatSymbols;
 import java.text.NumberFormat;
 
+import java.util.Collections;
 import java.util.Locale;
 
 /**
@@ -109,7 +109,7 @@ public final class BtcAutoFormat extends BtcFormat {
 
     /** Constructor */
     protected BtcAutoFormat(Locale locale, Style style, int fractionPlaces) {
-        super((DecimalFormat)NumberFormat.getCurrencyInstance(locale), fractionPlaces, ImmutableList.<Integer>of());
+        super((DecimalFormat)NumberFormat.getCurrencyInstance(locale), fractionPlaces, Collections.emptyList());
         style.apply(this.numberFormat);
     }
 

core/src/main/java/org/bitcoinj/utils/BtcFormat.java

@@ -20,8 +20,10 @@ import org.bitcoinj.utils.BtcAutoFormat.Style;
 import static org.bitcoinj.utils.BtcAutoFormat.Style.*;
 
 import org.bitcoinj.core.Coin;
+
+import java.util.Arrays;
+import java.util.Collections;
 import java.util.Objects;
-import com.google.common.collect.ImmutableList;
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
 import com.google.common.base.Strings;
@@ -1235,11 +1237,13 @@ public abstract class BtcFormat extends Format {
     /** Sets the number of fractional decimal places to be displayed on the given
      *  NumberFormat object to the value of the given integer.
      *  @return The minimum and maximum fractional places settings that the
-     *          formatter had before this change, as an ImmutableList. */
+     *          formatter had before this change, as an unmodifiable List. */
-    private static ImmutableList<Integer> setFormatterDigits(DecimalFormat formatter, int min, int max) {
+    private static List<Integer> setFormatterDigits(DecimalFormat formatter, int min, int max) {
-        ImmutableList<Integer> ante = ImmutableList.of(
+        List<Integer> ante = Collections.unmodifiableList(
+            Arrays.asList(
                 formatter.getMinimumFractionDigits(),
                 formatter.getMaximumFractionDigits()
+            )
         );
         formatter.setMinimumFractionDigits(min);
         formatter.setMaximumFractionDigits(max);

core/src/main/java/org/bitcoinj/wallet/BasicKeyChain.java

@@ -25,7 +25,6 @@ import org.bitcoinj.utils.ListenerRegistration;
 import org.bitcoinj.utils.Threading;
 import org.bitcoinj.wallet.listeners.KeyChainEventListener;
 
-import com.google.common.collect.ImmutableList;
 import com.google.protobuf.ByteString;
 import org.bouncycastle.crypto.params.KeyParameter;
 
@@ -84,7 +83,7 @@ public class BasicKeyChain implements EncryptableKeyChain {
                 checkState(keyCrypter == null);   // We will refuse to encrypt an empty key chain.
                 final ECKey key = new ECKey();
                 importKeyLocked(key);
-                queueOnKeysAdded(ImmutableList.of(key));
+                queueOnKeysAdded(Collections.singletonList(key));
             }
             return hashToKeys.values().iterator().next();
         } finally {
@@ -105,7 +104,7 @@ public class BasicKeyChain implements EncryptableKeyChain {
                     keys.add(new ECKey());
                 }
 
-                ImmutableList<ECKey> immutableKeys = ImmutableList.copyOf(keys);
+                List<ECKey> immutableKeys = Collections.unmodifiableList(keys);
                 importKeysLocked(immutableKeys);
                 queueOnKeysAdded(immutableKeys);
             }
@@ -133,7 +132,7 @@ public class BasicKeyChain implements EncryptableKeyChain {
     }
 
     public int importKeys(ECKey... keys) {
-        return importKeys(ImmutableList.copyOf(keys));
+        return importKeys(Collections.unmodifiableList(Arrays.asList(keys)));
     }
 
     public int importKeys(List<? extends ECKey> keys) {
@@ -198,7 +197,7 @@ public class BasicKeyChain implements EncryptableKeyChain {
             checkKeyEncryptionStateMatches(key);
             if (hasKey(key)) return;
             importKeyLocked(key);
-            queueOnKeysAdded(ImmutableList.of(key));
+            queueOnKeysAdded(Collections.singletonList(key));
         } finally {
             lock.unlock();
         }

core/src/main/java/org/bitcoinj/wallet/DeterministicKeyChain.java

@@ -28,7 +28,6 @@ import org.bitcoinj.wallet.listeners.KeyChainEventListener;
 
 import com.google.common.base.MoreObjects;
 import com.google.common.base.Stopwatch;
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterators;
 import com.google.common.collect.PeekingIterator;
 import com.google.protobuf.ByteString;
@@ -1310,14 +1309,14 @@ public class DeterministicKeyChain implements EncryptableKeyChain {
      * Returns leaf keys issued by this chain (including lookahead zone)
      */
     public List<DeterministicKey> getLeafKeys() {
-        ImmutableList.Builder<DeterministicKey> keys = ImmutableList.builder();
+        List<DeterministicKey> keys = new ArrayList<>();
         for (ECKey key : getKeys(true, false)) {
             DeterministicKey dKey = (DeterministicKey) key;
             if (dKey.getPath().size() == getAccountPath().size() + 2) {
                 keys.add(dKey);
             }
         }
-        return keys.build();
+        return Collections.unmodifiableList(keys);
     }
 
     /*package*/ static void serializeSeedEncryptableItem(DeterministicSeed seed, Protos.Key.Builder proto) {

core/src/main/java/org/bitcoinj/wallet/KeyChainGroup.java

@@ -447,7 +447,9 @@ public class KeyChainGroup implements KeyBag {
      */
     public final DeterministicKeyChain getActiveKeyChain(Script.ScriptType outputScriptType, long keyRotationTimeSecs) {
         checkState(isSupportsDeterministicChains(), "doesn't support deterministic chains");
-        for (DeterministicKeyChain chain : ImmutableList.copyOf(chains).reverse())
+        List<DeterministicKeyChain> chainsReversed = new ArrayList<>(chains);
+        Collections.reverse(chainsReversed);
+        for (DeterministicKeyChain chain : chainsReversed)
             if (chain.getOutputScriptType() == outputScriptType
                     && chain.getEarliestKeyCreationTime() >= keyRotationTimeSecs)
                 return chain;
@@ -508,7 +510,7 @@ public class KeyChainGroup implements KeyBag {
 
     /** Imports the given keys into the basic chain, creating it if necessary. */
     public int importKeys(ECKey... keys) {
-        return importKeys(ImmutableList.copyOf(keys));
+        return importKeys(Collections.unmodifiableList(Arrays.asList(keys)));
     }
 
     public boolean checkPassword(CharSequence password) {

core/src/main/java/org/bitcoinj/wallet/MarriedKeyChain.java

@@ -16,7 +16,6 @@
 
 package org.bitcoinj.wallet;
 
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.protobuf.ByteString;
 
@@ -32,6 +31,7 @@ import org.bitcoinj.script.ScriptBuilder;
 import org.bouncycastle.crypto.params.KeyParameter;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -151,25 +151,26 @@ public class MarriedKeyChain extends DeterministicKeyChain {
     @Override
     public Script freshOutputScript(KeyPurpose purpose) {
         DeterministicKey followedKey = getKey(purpose);
-        ImmutableList.Builder<ECKey> keys = ImmutableList.<ECKey>builder().add(followedKey);
+        List<ECKey> keys = new ArrayList<>();
+        keys.add(followedKey);
         for (DeterministicKeyChain keyChain : followingKeyChains) {
             DeterministicKey followingKey = keyChain.getKey(purpose);
             checkState(followedKey.getChildNumber().equals(followingKey.getChildNumber()), "Following keychains should be in sync");
             keys.add(followingKey);
         }
-        List<ECKey> marriedKeys = keys.build();
+        List<ECKey> marriedKeys = Collections.unmodifiableList(keys);
         Script redeemScript = ScriptBuilder.createRedeemScript(sigsRequiredToSpend, marriedKeys);
         return ScriptBuilder.createP2SHOutputScript(redeemScript);
     }
 
     private List<ECKey> getMarriedKeysWithFollowed(DeterministicKey followedKey) {
-        ImmutableList.Builder<ECKey> keys = ImmutableList.builder();
+        List<ECKey> keys = new ArrayList<>();
         for (DeterministicKeyChain keyChain : followingKeyChains) {
             keyChain.maybeLookAhead();
             keys.add(keyChain.getKeyByPath(followedKey.getPath()));
         }
         keys.add(followedKey);
-        return keys.build();
+        return Collections.unmodifiableList(keys);
     }
 
     /** Get the redeem data for a key in this married chain */

core/src/main/java/org/bitcoinj/wallet/Wallet.java

@@ -19,7 +19,6 @@ package org.bitcoinj.wallet;
 
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
@@ -542,7 +541,7 @@ public class Wallet extends BaseTaggableObject
     public List<TransactionSigner> getTransactionSigners() {
         lock.lock();
         try {
-            return ImmutableList.copyOf(signers);
+            return Collections.unmodifiableList(signers);
         } finally {
             lock.unlock();
         }
@@ -1041,7 +1040,7 @@ public class Wallet extends BaseTaggableObject
      * @return true if successful
      */
     public boolean removeWatchedAddress(final Address address) {
-        return removeWatchedAddresses(ImmutableList.of(address));
+        return removeWatchedAddresses(Collections.singletonList(address));
     }
 
     /**
@@ -1903,7 +1902,7 @@ public class Wallet extends BaseTaggableObject
         lock.lock();
         try {
             if (dependencies == null)
-                dependencies = ImmutableList.of();
+                dependencies = Collections.emptyList();
             RiskAnalysis analysis = riskAnalyzer.create(this, tx, dependencies);
             RiskAnalysis.Result result = analysis.analyze();
             if (result != RiskAnalysis.Result.OK) {

tools/src/main/java/org/bitcoinj/tools/WatchMempool.java

@@ -17,7 +17,9 @@
 
 package org.bitcoinj.tools;
 
+import java.util.Collections;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 import org.bitcoinj.core.listeners.*;
@@ -33,12 +35,10 @@ import org.bitcoinj.wallet.RiskAnalysis.Result;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.collect.ImmutableList;
-
 public class WatchMempool {
     private static final Logger log = LoggerFactory.getLogger(WatchMempool.class);
     private static final NetworkParameters PARAMS = MainNetParams.get();
-    private static final ImmutableList<Transaction> NO_DEPS = ImmutableList.of();
+    private static final List<Transaction> NO_DEPS = Collections.emptyList();
     private static final Map<String, Integer> counters = new HashMap<>();
     private static final String TOTAL_KEY = "TOTAL";
     private static final long START_MS = System.currentTimeMillis();

wallettool/src/main/java/org/bitcoinj/wallettool/WalletTool.java

@@ -39,7 +39,6 @@ import org.bitcoinj.wallet.DeterministicSeed;
 
 import com.google.common.base.CharMatcher;
 import com.google.common.base.Splitter;
-import com.google.common.collect.ImmutableList;
 import com.google.common.io.BaseEncoding;
 import com.google.common.io.Resources;
 import com.google.protobuf.ByteString;
@@ -93,6 +92,8 @@ import java.nio.charset.StandardCharsets;
 import java.security.SecureRandom;
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Date;
 import java.util.LinkedList;
 import java.util.List;
@@ -585,13 +586,13 @@ public class WalletTool implements Callable<Integer> {
         }
 
         String[] xpubkeys = xpubKeysStr.split(",");
-        ImmutableList.Builder<DeterministicKey> keys = ImmutableList.builder();
+        List<DeterministicKey> keys = new ArrayList<>();
         for (String xpubkey : xpubkeys) {
             keys.add(DeterministicKey.deserializeB58(null, xpubkey.trim(), params));
         }
         MarriedKeyChain chain = MarriedKeyChain.builder()
                 .random(new SecureRandom())
-                .followingKeys(keys.build())
+                .followingKeys(Collections.unmodifiableList(keys))
                 .build();
         wallet.addAndActivateHDChain(chain);
     }
@@ -908,7 +909,7 @@ public class WalletTool implements Callable<Integer> {
         // Send the payment
         try {
             // No refund address specified, no user-specified memo field.
-            PaymentProtocol.Ack ack = session.sendPayment(ImmutableList.of(req.tx), null, null).get();
+            PaymentProtocol.Ack ack = session.sendPayment(Collections.singletonList(req.tx), null, null).get();
             wallet.commitTx(req.tx);
             System.out.println("Memo from server: " + ack.getMemo());
         } catch (ExecutionException e) {
@@ -1106,8 +1107,8 @@ public class WalletTool implements Callable<Integer> {
         if (seedStr != null) {
             DeterministicSeed seed;
             // Parse as mnemonic code.
-            final List<String> split = ImmutableList
+            final List<String> split = Collections
-                    .copyOf(Splitter.on(CharMatcher.anyOf(" :;,")).omitEmptyStrings().split(seedStr));
+                    .unmodifiableList(Splitter.on(CharMatcher.anyOf(" :;,")).omitEmptyStrings().splitToList(seedStr));
             String passphrase = ""; // TODO allow user to specify a passphrase
             seed = new DeterministicSeed(split, null, passphrase, creationTimeSecs);
             try {