Clean up toString and other string-related code.

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

@@ -142,13 +142,7 @@ public class AddressMessage extends Message {
 
     @Override
     public String toString() {
-        StringBuilder builder = new StringBuilder();
+        return "addr: " + Utils.join(addresses);
-        builder.append("addr: ");
-        for (PeerAddress a : addresses) {
-            builder.append(a.toString());
-            builder.append(" ");
-        }
-        return builder.toString();
     }
 
 }

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

@@ -585,27 +585,15 @@ public class Block extends Message {
         StringBuilder s = new StringBuilder("v");
         s.append(version);
         s.append(" block: \n");
-        s.append("   previous block: ");
+        s.append("   previous block: ").append(getPrevBlockHash()).append("\n");
-        s.append(getPrevBlockHash());
+        s.append("   merkle root: ").append(getMerkleRoot()).append("\n");
-        s.append("\n");
+        s.append("   time: [").append(time).append("] ").append(Utils.dateTimeFormat(time * 1000)).append("\n");
-        s.append("   merkle root: ");
+        s.append("   difficulty target (nBits): ").append(difficultyTarget).append("\n");
-        s.append(getMerkleRoot());
+        s.append("   nonce: ").append(nonce).append("\n");
-        s.append("\n");
-        s.append("   time: [");
-        s.append(time);
-        s.append("] ");
-        s.append(Utils.dateTimeFormat(time * 1000));
-        s.append("\n");
-        s.append("   difficulty target (nBits): ");
-        s.append(difficultyTarget);
-        s.append("\n");
-        s.append("   nonce: ");
-        s.append(nonce);
-        s.append("\n");
         if (transactions != null && transactions.size() > 0) {
             s.append("   with ").append(transactions.size()).append(" transaction(s):\n");
             for (Transaction tx : transactions) {
-                s.append(tx.toString());
+                s.append(tx);
             }
         }
         return s.toString();

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

@@ -76,13 +76,7 @@ public class GetBlocksMessage extends Message {
 
     @Override
     public String toString() {
-        StringBuffer b = new StringBuffer();
+        return "getblocks: " + Utils.join(locator);
-        b.append("getblocks: ");
-        for (Sha256Hash hash : locator) {
-            b.append(hash.toString());
-            b.append(" ");
-        }
-        return b.toString();
     }
 
     @Override

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

@@ -35,13 +35,7 @@ public class GetHeadersMessage extends GetBlocksMessage {
 
     @Override
     public String toString() {
-        StringBuffer b = new StringBuffer();
+        return "getheaders: " + Utils.join(locator);
-        b.append("getheaders: ");
-        for (Sha256Hash hash : locator) {
-            b.append(hash.toString());
-            b.append(" ");
-        }
-        return b.toString();
     }
 
     /**

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

@@ -40,7 +40,7 @@ public class InventoryItem {
 
     @Override
     public String toString() {
-        return type.toString() + ": " + hash;
+        return type + ": " + hash;
     }
 
     @Override

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

@@ -273,12 +273,8 @@ public class Peer extends PeerSocketHandler {
     @Override
     public String toString() {
         PeerAddress addr = getAddress();
-        if (addr == null) {
+        // if null, it's a user-provided NetworkConnection object
-            // User-provided NetworkConnection object.
+        return addr == null ? "Peer()" : addr.toString();
-            return "Peer()";
-        } else {
-            return addr.toString();
-        }
     }
 
     @Override
@@ -501,9 +497,9 @@ public class Peer extends PeerSocketHandler {
     private void processAlert(AlertMessage m) {
         try {
             if (m.isSignatureValid()) {
-                log.info("Received alert from peer {}: {}", toString(), m.getStatusBar());
+                log.info("Received alert from peer {}: {}", this, m.getStatusBar());
             } else {
-                log.warn("Received alert with invalid signature from peer {}: {}", toString(), m.getStatusBar());
+                log.warn("Received alert with invalid signature from peer {}: {}", this, m.getStatusBar());
             }
         } catch (Throwable t) {
             // Signature checking can FAIL on Android platforms before Gingerbread apparently due to bugs in their
@@ -1306,7 +1302,7 @@ public class Peer extends PeerSocketHandler {
         }
         if (log.isDebugEnabled())
             log.debug("{}: blockChainDownloadLocked({}) current head = {}",
-                    toString(), toHash.toString(), chainHead.getHeader().getHashAsString());
+                    this, toHash, chainHead.getHeader().getHashAsString());
         StoredBlock cursor = chainHead;
         for (int i = 100; cursor != null && i > 0; i--) {
             blockLocator.add(cursor.getHeader().getHash());

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

@@ -152,12 +152,8 @@ public class RejectMessage extends Message {
     @Override
     public String toString() {
         Sha256Hash hash = getRejectedObjectHash();
-        if (hash != null)
+        return String.format("Reject: %s %s for reason '%s' (%d)", getRejectedMessage(),
-            return String.format("Reject: %s %s for reason '%s' (%d)", getRejectedMessage(), getRejectedObjectHash(),
+            hash != null ? hash : "", getReasonString(), getReasonCode().code);
-                getReasonString(), getReasonCode().code);
-        else
-            return String.format("Reject: %s for reason '%s' (%d)", getRejectedMessage(),
-                getReasonString(), getReasonCode().code);
     }
 
     @Override

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

@@ -86,6 +86,6 @@ public class StoredUndoableBlock implements Serializable {
 
     @Override
     public String toString() {
-        return "Undoable Block " + blockHash.toString();
+        return "Undoable Block " + blockHash;
     }
 }

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

@@ -647,7 +647,8 @@ public class Transaction extends ChildMessage implements Serializable {
                 script = "???";
                 script2 = "???";
             }
-            s.append("     == COINBASE TXN (scriptSig " + script + ")  (scriptPubKey " + script2 + ")\n");
+            s.append("     == COINBASE TXN (scriptSig ").append(script)
+                .append(")  (scriptPubKey ").append(script2).append(")\n");
             return s.toString();
         }
         for (TransactionInput in : inputs) {

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

@@ -322,12 +322,7 @@ public class TransactionConfidence implements Serializable {
         StringBuilder builder = new StringBuilder();
         int peers = numBroadcastPeers();
         if (peers > 0) {
-            builder.append("Seen by ");
+            builder.append("Seen by ").append(peers).append(peers > 1 ? " peers. " : " peer. ");
-            builder.append(peers);
-            if (peers > 1)
-                builder.append(" peers. ");
-            else
-                builder.append(" peer. ");
         }
         switch (getConfidenceType()) {
             case UNKNOWN:

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

@@ -279,10 +279,8 @@ public class TransactionInput extends ChildMessage implements Serializable {
      */
     @Override
     public String toString() {
-        if (isCoinBase())
-            return "TxIn: COINBASE";
         try {
-            return "TxIn for [" + outpoint + "]: " + getScriptSig();
+            return isCoinBase() ? "TxIn: COINBASE" : "TxIn for [" + outpoint + "]: " + getScriptSig();
         } catch (ScriptException e) {
             throw new RuntimeException(e);
         }

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

@@ -193,10 +193,9 @@ public class TransactionOutPoint extends ChildMessage implements Serializable {
 
     @Override
     public String toString() {
-        return hash.toString() + ":" + index;
+        return hash + ":" + index;
     }
 
-
     /**
      * Returns the hash of the transaction this outpoint references/spends/is connected to.
      */

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

@@ -354,8 +354,7 @@ public class TransactionOutput extends ChildMessage implements Serializable {
                 buf.append(" to multisig");
             else
                 buf.append(" (unknown type)");
-            buf.append(" script:");
+            buf.append(" script:").append(script);
-            buf.append(script);
             return buf.toString();
         } catch (ScriptException e) {
             throw new RuntimeException(e);

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

@@ -156,7 +156,7 @@ public class UTXO implements Serializable {
 
     @Override
     public String toString() {
-        return String.format("Stored TxOut of %s (%s:%d)", value.toFriendlyString(), hash.toString(), index);
+        return String.format("Stored TxOut of %s (%s:%d)", value.toFriendlyString(), hash, index);
     }
 
     @Override

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

@@ -54,6 +54,8 @@ public class Utils {
     public static final String BITCOIN_SIGNED_MESSAGE_HEADER = "Bitcoin Signed Message:\n";
     public static final byte[] BITCOIN_SIGNED_MESSAGE_HEADER_BYTES = BITCOIN_SIGNED_MESSAGE_HEADER.getBytes(Charsets.UTF_8);
 
+    private static final Joiner SPACE_JOINER = Joiner.on(" ");
+
     private static BlockingQueue<Boolean> mockSleepQueue;
 
     /**
@@ -407,6 +409,18 @@ public class Utils {
         return iso8601.format(dateTime);
     }
 
+    /**
+     * Returns a string containing the string representation of the given items,
+     * delimited by a single space character.
+     *
+     * @param items the items to join
+     * @param <T> the item type
+     * @return the joined space-delimited string
+     */
+    public static <T> String join(Iterable<T> items) {
+        return SPACE_JOINER.join(items);
+    }
+
     public static byte[] copyOf(byte[] in, int length) {
         byte[] out = new byte[length];
         System.arraycopy(in, 0, out, 0, Math.min(length, in.length));

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

@@ -2768,9 +2768,7 @@ public class Wallet extends BaseTaggableObject implements Serializable, BlockCha
             if (!watchedScripts.isEmpty()) {
                 builder.append("\nWatched scripts:\n");
                 for (Script script : watchedScripts) {
-                    builder.append("  ");
+                    builder.append("  ").append(script).append("\n");
-                    builder.append(script.toString());
-                    builder.append("\n");
                 }
             }
 

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

@@ -617,18 +617,11 @@ public class DeterministicKey extends ECKey {
     @Override
     public void formatKeyWithAddress(boolean includePrivateKeys, StringBuilder builder, NetworkParameters params) {
         final Address address = toAddress(params);
-        builder.append("  addr:");
+        builder.append("  addr:").append(address);
-        builder.append(address.toString());
+        builder.append("  hash160:").append(Utils.HEX.encode(getPubKeyHash()));
-        builder.append("  hash160:");
+        builder.append("  (").append(getPathAsString()).append(")\n");
-        builder.append(Utils.HEX.encode(getPubKeyHash()));
-        builder.append("  (");
-        builder.append(getPathAsString());
-        builder.append(")");
-        builder.append("\n");
         if (includePrivateKeys) {
-            builder.append("  ");
+            builder.append("  ").append(toStringWithPrivate(params)).append("\n");
-            builder.append(toStringWithPrivate(params));
-            builder.append("\n");
         }
     }
 }

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

@@ -51,6 +51,7 @@ public final class EncryptedData {
 
     @Override
     public String toString() {
-        return "EncryptedData [initialisationVector=" + Arrays.toString(initialisationVector) + ", encryptedPrivateKey=" + Arrays.toString(encryptedBytes) + "]";
+        return "EncryptedData [initialisationVector=" + Arrays.toString(initialisationVector)
+            + ", encryptedPrivateKey=" + Arrays.toString(encryptedBytes) + "]";
     }
 }

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

@@ -19,7 +19,6 @@ package org.bitcoinj.crypto;
 
 import org.bitcoinj.core.Sha256Hash;
 import org.bitcoinj.core.Utils;
-import com.google.common.base.Joiner;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -126,7 +125,7 @@ public class MnemonicCode {
         // used as a pseudo-random function. Desired length of the
         // derived key is 512 bits (= 64 bytes).
         //
-        String pass = Joiner.on(' ').join(words);
+        String pass = Utils.join(words);
         String salt = "mnemonic" + passphrase;
 
         long start = System.currentTimeMillis();

core/src/main/java/org/bitcoinj/protocols/channels/PaymentChannelCloseException.java

@@ -79,6 +79,6 @@ public class PaymentChannelCloseException extends Exception {
 
     @Override
     public String toString() {
-        return "PaymentChannelCloseException for reason " + getCloseReason().toString();
+        return "PaymentChannelCloseException for reason " + getCloseReason();
     }
 }

core/src/main/java/org/bitcoinj/protocols/channels/StoredServerChannel.java

@@ -110,7 +110,7 @@ public class StoredServerChannel {
                 "    Client output: %s%n" +
                 "    Refund unlock: %s (%d unix time)%n" +
                 "    Contract:    %s%n",
-                connectedHandler != null ? "connected" : "disconnected", myKey, bestValueToMe.toString(),
+                connectedHandler != null ? "connected" : "disconnected", myKey, bestValueToMe,
                 clientOutput,  new Date(refundTransactionUnlockTimeSecs * 1000), refundTransactionUnlockTimeSecs,
                 contract.toString().replaceAll(newline, newline + "    "));
     }

core/src/main/java/org/bitcoinj/script/Script.java

@@ -125,12 +125,7 @@ public class Script {
      */
     @Override
     public String toString() {
-        StringBuilder buf = new StringBuilder();
+        return Utils.join(chunks);
-        for (ScriptChunk chunk : chunks)
-            buf.append(chunk).append(' ');
-        if (buf.length() > 0)
-            buf.setLength(buf.length() - 1);
-        return buf.toString();
     }
 
     /** Returns the serialized program as a newly created byte array. */
@@ -297,7 +292,7 @@ public class Script {
             // A large constant followed by an OP_CHECKSIG is the key.
             return chunk0data;
         } else {
-            throw new ScriptException("Script did not match expected form: " + toString());
+            throw new ScriptException("Script did not match expected form: " + this);
         }
     }
 

core/src/main/java/org/bitcoinj/script/ScriptChunk.java

@@ -139,10 +139,7 @@ public class ScriptChunk {
             buf.append(getOpCodeName(opcode));
         } else if (data != null) {
             // Data chunk
-            buf.append(getPushDataName(opcode));
+            buf.append(getPushDataName(opcode)).append("[").append(Utils.HEX.encode(data)).append("]");
-            buf.append("[");
-            buf.append(Utils.HEX.encode(data));
-            buf.append("]");
         } else {
             // Small num
             buf.append(Script.decodeFromOpN(opcode));

core/src/main/java/org/bitcoinj/store/MemoryFullPrunedBlockStore.java

@@ -68,7 +68,7 @@ class StoredTransactionOutPoint implements Serializable {
     
     @Override
     public String toString() {
-        return "Stored transaction out point: " + hash.toString() + ":" + index;
+        return "Stored transaction out point: " + hash + ":" + index;
     }
 
     @Override

core/src/main/java/org/bitcoinj/uri/BitcoinURI.java

@@ -337,7 +337,7 @@ public class BitcoinURI {
             } else {
                 builder.append(",");
             }
-            builder.append("'").append(entry.getKey()).append("'=").append("'").append(entry.getValue().toString()).append("'");
+            builder.append("'").append(entry.getKey()).append("'=").append("'").append(entry.getValue()).append("'");
         }
         builder.append("]");
         return builder.toString();

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

@@ -1157,8 +1157,7 @@ public abstract class BtcFormat extends Format {
      * @throws IllegalArgumentException if the number of fraction places is negative.
      */
     public String format(Object qty, int minDecimals, int... fractionGroups) {
-        return format(qty, new StringBuffer(), new FieldPosition(0), minDecimals, boxAsList(fractionGroups)).
+        return format(qty, new StringBuffer(), new FieldPosition(0), minDecimals, boxAsList(fractionGroups)).toString();
-               toString();
     }
 
     /**
@@ -1542,9 +1541,9 @@ public abstract class BtcFormat extends Format {
      *  returned by this method is localized, any currency signs expressed are literally, and
      *  optional fractional decimal places are shown grouped in parentheses. */
     public String pattern() { synchronized(numberFormat) {
-        StringBuffer groups = new StringBuffer();
+        StringBuilder groups = new StringBuilder();
         for (int group : decimalGroups) {
-            groups.append("(" + Strings.repeat("#",group) + ")");
+            groups.append("(").append(Strings.repeat("#", group)).append(")");
         }
         DecimalFormatSymbols s = numberFormat.getDecimalFormatSymbols();
         String digit = String.valueOf(s.getDigit());

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

@@ -25,7 +25,6 @@ import org.bitcoinj.script.Script;
 import org.bitcoinj.store.UnreadableWalletException;
 import org.bitcoinj.utils.Threading;
 
-import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterators;
 import com.google.common.collect.PeekingIterator;
@@ -1333,7 +1332,7 @@ public class DeterministicKeyChain implements EncryptableKeyChain {
             } else if (includePrivateKeys) {
                 final List<String> words = seed.getMnemonicCode();
                 builder2.append(
-                        String.format("Seed as words: %s%nSeed as hex:   %s%n", Joiner.on(' ').join(words),
+                        String.format("Seed as words: %s%nSeed as hex:   %s%n", Utils.join(words),
                                 seed.toHexString())
                 );
             }

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

@@ -21,7 +21,6 @@ import org.bitcoinj.core.Utils;
 import org.bitcoinj.crypto.*;
 import org.bitcoinj.store.UnreadableWalletException;
 import com.google.common.base.Charsets;
-import com.google.common.base.Joiner;
 import com.google.common.base.Splitter;
 import org.spongycastle.crypto.params.KeyParameter;
 
@@ -132,10 +131,9 @@ public class DeterministicSeed implements EncryptableItem {
 
     @Override
     public String toString() {
-        if (isEncrypted())
+        return isEncrypted()
-            return "DeterministicSeed [encrypted]";
+            ? "DeterministicSeed [encrypted]"
-        else
+            : "DeterministicSeed " + toHexString() + " " + Utils.join(mnemonicCode);
-            return "DeterministicSeed " + toHexString() + " " + Joiner.on(" ").join(mnemonicCode);
     }
 
     /** Returns the seed as hex or null if encrypted. */
@@ -185,7 +183,7 @@ public class DeterministicSeed implements EncryptableItem {
     }
 
     private byte[] getMnemonicAsBytes() {
-        return Joiner.on(" ").join(mnemonicCode).getBytes(Charsets.UTF_8);
+        return Utils.join(mnemonicCode).getBytes(Charsets.UTF_8);
     }
 
     public DeterministicSeed decrypt(KeyCrypter crypter, String passphrase, KeyParameter aesKey) {

core/src/test/java/org/bitcoinj/crypto/KeyCrypterScryptTest.java

@@ -104,12 +104,12 @@ public class KeyCrypterScryptTest {
         KeyCrypterScrypt keyCrypter = new KeyCrypterScrypt(scryptParameters);
 
         // create a longer encryption string
-        StringBuilder stringBuffer = new StringBuilder();
+        StringBuilder builder = new StringBuilder();
         for (int i = 0; i < 100; i++) {
-            stringBuffer.append(i).append(" ").append("The quick brown fox");
+            builder.append(i).append(" The quick brown fox");
         }
 
-        EncryptedData data = keyCrypter.encrypt(stringBuffer.toString().getBytes(), keyCrypter.deriveKey(PASSWORD2));
+        EncryptedData data = keyCrypter.encrypt(builder.toString().getBytes(), keyCrypter.deriveKey(PASSWORD2));
         assertNotNull(data);
 
         try {

core/src/test/java/org/bitcoinj/crypto/MnemonicCodeTest.java

@@ -17,7 +17,7 @@
 
 package org.bitcoinj.crypto;
 
-import com.google.common.base.Joiner;
+import org.bitcoinj.core.Utils;
 import com.google.common.collect.Lists;
 import org.junit.Before;
 import org.junit.Test;
@@ -171,7 +171,7 @@ public class MnemonicCodeTest {
             byte[] entropy = mc.toEntropy(split(vecCode));
 
             assertEquals(vecData, HEX.encode(entropy));
-            assertEquals(vecCode, Joiner.on(' ').join(code));
+            assertEquals(vecCode, Utils.join(code));
             assertEquals(vecSeed, HEX.encode(seed));
         }
     }

examples/src/main/java/org/bitcoinj/examples/BackupToMnemonicSeed.java

@@ -1,10 +1,10 @@
 package org.bitcoinj.examples;
 
 import org.bitcoinj.core.NetworkParameters;
+import org.bitcoinj.core.Utils;
 import org.bitcoinj.core.Wallet;
 import org.bitcoinj.params.TestNet3Params;
 import org.bitcoinj.wallet.DeterministicSeed;
-import com.google.common.base.Joiner;
 
 /**
  * The following example shows you how to create a deterministic seed from a hierarchical deterministic wallet represented as a mnemonic code.
@@ -25,6 +25,6 @@ public class BackupToMnemonicSeed {
         System.out.println("seed: " + seed.toString());
 
         System.out.println("creation time: " + seed.getCreationTimeSeconds());
-        System.out.println("mnemonicCode: " + Joiner.on(" ").join(seed.getMnemonicCode()));
+        System.out.println("mnemonicCode: " + Utils.join(seed.getMnemonicCode()));
     }
 }

wallettemplate/src/main/java/wallettemplate/WalletSettingsController.java

@@ -1,8 +1,8 @@
 package wallettemplate;
 
+import org.bitcoinj.core.Utils;
 import org.bitcoinj.crypto.MnemonicCode;
 import org.bitcoinj.wallet.DeterministicSeed;
-import com.google.common.base.Joiner;
 import com.google.common.base.Splitter;
 import com.google.common.util.concurrent.Service;
 import javafx.application.Platform;
@@ -68,7 +68,7 @@ public class WalletSettingsController {
         // Set the mnemonic seed words.
         final List<String> mnemonicCode = seed.getMnemonicCode();
         checkNotNull(mnemonicCode);    // Already checked for encryption.
-        String origWords = Joiner.on(" ").join(mnemonicCode);
+        String origWords = Utils.join(mnemonicCode);
         wordsArea.setText(origWords);
 
         // Validate words as they are being typed.