Remove the dependency on Guava.

build.gradle

@@ -50,17 +50,12 @@ shadowJar {
         exclude 'com.android.org.conscrypt'
     }
     relocate 'net.', 'shadow.net.'
-    relocate 'javax.annotation', 'shadow.javax.annotation'
-    relocate 'org.apache', 'shadow.org.apache'
-    relocate 'org.jvnet', 'shadow.org.jvnet'
-    relocate 'org.codehaus', 'shadow.org.codehaus'
-    relocate 'org.threeten', 'shadow.org.threeten'
-    relocate 'org.checkerframework', 'shadow.org.checkerframework'
     relocate 'okhttp3', 'shadow.okhttp3'
     relocate 'okio', 'shadow.okio'
     relocate 'kotlin', 'shadow.kotlin'
     relocate 'org.intellij', 'shadow.org.intellij'
     relocate 'org.jetbrains', 'shadow.org.jetbrains'
+    relocate 'org.apache', 'shadow.org.apache'
 }
 
 repositories {
@@ -71,11 +66,9 @@ dependencies {
     implementation "com.squareup.okhttp3:okhttp:${okhttpclientVersion}"
     implementation "com.squareup.okhttp3:okhttp-sse:${okhttpclientVersion}"
     implementation 'com.moandjiezana.toml:toml4j:0.7.2'
-    // use the android version because we don't want java 8 stuff
-    // TODO: Do we really need to introduce guava?
-    implementation 'com.google.guava:guava:32.1.2-android'
     implementation 'com.google.code.gson:gson:2.10.1'
     implementation 'net.i2p.crypto:eddsa:0.3.0'
+    implementation 'commons-codec:commons-codec:1.16.0'
 
     testImplementation 'org.mockito:mockito-core:5.5.0'
     testImplementation "com.squareup.okhttp3:mockwebserver:${okhttpclientVersion}"

src/main/java/org/stellar/sdk/AbstractTransaction.java

@@ -1,28 +1,27 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.collect.ImmutableList;
-import com.google.common.io.BaseEncoding;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import lombok.NonNull;
 import org.stellar.sdk.xdr.DecoratedSignature;
 import org.stellar.sdk.xdr.Hash;
 import org.stellar.sdk.xdr.SignatureHint;
 import org.stellar.sdk.xdr.TransactionEnvelope;
 import org.stellar.sdk.xdr.TransactionSignaturePayload;
 
 public abstract class AbstractTransaction {
+
   protected final Network mNetwork;
   protected final AccountConverter accountConverter;
   protected List<DecoratedSignature> mSignatures;
   public static final int MIN_BASE_FEE = 100;
 
-  AbstractTransaction(AccountConverter accountConverter, Network network) {
-    this.accountConverter = checkNotNull(accountConverter, "accountConverter cannot be null");
-    this.mNetwork = checkNotNull(network, "network cannot be null");
+  AbstractTransaction(@NonNull AccountConverter accountConverter, @NonNull Network network) {
+    this.accountConverter = accountConverter;
+    this.mNetwork = network;
     this.mSignatures = new ArrayList<DecoratedSignature>();
   }
 
@@ -31,8 +30,7 @@ public abstract class AbstractTransaction {
    *
    * @param signer {@link KeyPair} object representing a signer
    */
-  public void sign(KeyPair signer) {
-    checkNotNull(signer, "signer cannot be null");
+  public void sign(@NonNull KeyPair signer) {
     byte[] txHash = this.hash();
     mSignatures.add(signer.signDecorated(txHash));
   }
@@ -42,8 +40,7 @@ public void sign(KeyPair signer) {
    *
    * @param preimage the sha256 hash of preimage should be equal to signer hash
    */
-  public void sign(byte[] preimage) {
-    checkNotNull(preimage, "preimage cannot be null");
+  public void sign(byte @NonNull [] preimage) {
     org.stellar.sdk.xdr.Signature signature = new org.stellar.sdk.xdr.Signature();
     signature.setSignature(preimage);
 
@@ -66,7 +63,7 @@ public byte[] hash() {
 
   /** Returns transaction hash encoded as a hexadecimal string. */
   public String hashHex() {
-    return BaseEncoding.base16().lowerCase().encode(this.hash());
+    return Util.bytesToHex(this.hash()).toLowerCase();
   }
 
   /** Returns signature base. */
@@ -96,7 +93,7 @@ public AccountConverter getAccountConverter() {
    * @return immutable list of signatures
    */
   public List<DecoratedSignature> getSignatures() {
-    return ImmutableList.copyOf(mSignatures);
+    return Collections.unmodifiableList(mSignatures);
   }
 
   /**

src/main/java/org/stellar/sdk/Account.java

@@ -1,8 +1,7 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
+import lombok.NonNull;
 
 /**
  * Represents an account in Stellar network with it's sequence number. Account object is required to
@@ -21,9 +20,9 @@ public class Account implements TransactionBuilderAccount {
    * @param sequenceNumber Current sequence number of the account (can be obtained using
    *     java-stellar-sdk or horizon server)
    */
-  public Account(String accountId, Long sequenceNumber) {
-    mAccountId = checkNotNull(accountId, "accountId cannot be null");
-    mSequenceNumber = checkNotNull(sequenceNumber, "sequenceNumber cannot be null");
+  public Account(@NonNull String accountId, @NonNull Long sequenceNumber) {
+    mAccountId = accountId;
+    mSequenceNumber = sequenceNumber;
   }
 
   @Override
@@ -57,7 +56,7 @@ public void incrementSequenceNumber() {
   }
 
   public int hashCode() {
-    return Objects.hashCode(this.mAccountId, this.mSequenceNumber);
+    return Objects.hash(this.mAccountId, this.mSequenceNumber);
   }
 
   @Override
@@ -67,7 +66,7 @@ public boolean equals(Object object) {
     }
 
     Account other = (Account) object;
-    return Objects.equal(this.mAccountId, other.mAccountId)
-        && Objects.equal(this.mSequenceNumber, other.mSequenceNumber);
+    return Objects.equals(this.mAccountId, other.mAccountId)
+        && Objects.equals(this.mSequenceNumber, other.mSequenceNumber);
   }
 }

src/main/java/org/stellar/sdk/AccountMergeOperation.java

@@ -1,8 +1,7 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
+import lombok.NonNull;
 import org.stellar.sdk.xdr.Operation.OperationBody;
 import org.stellar.sdk.xdr.OperationType;
 
@@ -17,8 +16,8 @@ public class AccountMergeOperation extends Operation {
 
   private final String destination;
 
-  private AccountMergeOperation(String destination) {
-    this.destination = checkNotNull(destination, "destination cannot be null");
+  private AccountMergeOperation(@NonNull String destination) {
+    this.destination = destination;
   }
 
   /** The account that receives the remaining XLM balance of the source account. */
@@ -79,7 +78,7 @@ public AccountMergeOperation build() {
   }
 
   public int hashCode() {
-    return Objects.hashCode(this.destination, this.getSourceAccount());
+    return Objects.hash(this.destination, this.getSourceAccount());
   }
 
   @Override
@@ -89,7 +88,7 @@ public boolean equals(Object object) {
     }
 
     AccountMergeOperation other = (AccountMergeOperation) object;
-    return Objects.equal(this.destination, other.destination)
-        && Objects.equal(this.getSourceAccount(), other.getSourceAccount());
+    return Objects.equals(this.destination, other.destination)
+        && Objects.equals(this.getSourceAccount(), other.getSourceAccount());
   }
 }

src/main/java/org/stellar/sdk/AllowTrustOperation.java

@@ -1,8 +1,7 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
+import lombok.NonNull;
 import org.stellar.sdk.xdr.*;
 
 /**
@@ -21,9 +20,12 @@ public class AllowTrustOperation extends Operation {
   private final boolean authorizeToMaintainLiabilities;
 
   private AllowTrustOperation(
-      String trustor, String assetCode, boolean authorize, boolean authorizeToMaintainLiabilities) {
-    this.trustor = checkNotNull(trustor, "trustor cannot be null");
-    this.assetCode = checkNotNull(assetCode, "assetCode cannot be null");
+      @NonNull String trustor,
+      @NonNull String assetCode,
+      boolean authorize,
+      boolean authorizeToMaintainLiabilities) {
+    this.trustor = trustor;
+    this.assetCode = assetCode;
     this.authorize = authorize;
     this.authorizeToMaintainLiabilities = authorizeToMaintainLiabilities;
   }
@@ -165,7 +167,7 @@ public AllowTrustOperation build() {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(
+    return Objects.hash(
         this.getSourceAccount(),
         this.assetCode,
         this.authorize,
@@ -180,10 +182,10 @@ public boolean equals(Object object) {
     }
 
     AllowTrustOperation other = (AllowTrustOperation) object;
-    return Objects.equal(this.assetCode, other.assetCode)
-        && Objects.equal(this.authorize, other.authorize)
-        && Objects.equal(this.authorizeToMaintainLiabilities, other.authorizeToMaintainLiabilities)
-        && Objects.equal(this.trustor, other.trustor)
-        && Objects.equal(this.getSourceAccount(), other.getSourceAccount());
+    return Objects.equals(this.assetCode, other.assetCode)
+        && Objects.equals(this.authorize, other.authorize)
+        && Objects.equals(this.authorizeToMaintainLiabilities, other.authorizeToMaintainLiabilities)
+        && Objects.equals(this.trustor, other.trustor)
+        && Objects.equals(this.getSourceAccount(), other.getSourceAccount());
   }
 }

src/main/java/org/stellar/sdk/AssetAmount.java

@@ -1,7 +1,7 @@
 package org.stellar.sdk;
 
-import com.google.common.base.Objects;
 import com.google.gson.annotations.SerializedName;
+import java.util.Objects;
 
 public final class AssetAmount {
   @SerializedName("asset")
@@ -24,7 +24,7 @@ public String getAmount() {
   }
 
   public int hashCode() {
-    return Objects.hashCode(asset, amount);
+    return Objects.hash(asset, amount);
   }
 
   @Override
@@ -34,7 +34,7 @@ public boolean equals(Object object) {
     }
 
     AssetAmount o = (AssetAmount) object;
-    return Objects.equal(this.getAsset(), o.getAsset())
-        && Objects.equal(this.getAmount(), o.getAmount());
+    return Objects.equals(this.getAsset(), o.getAsset())
+        && Objects.equals(this.getAmount(), o.getAmount());
   }
 }

src/main/java/org/stellar/sdk/AssetTypeCreditAlphaNum.java

@@ -1,8 +1,7 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
+import lombok.NonNull;
 
 /**
  * Base class for AssetTypeCreditAlphaNum4 and AssetTypeCreditAlphaNum12 subclasses.
@@ -13,9 +12,7 @@ public abstract class AssetTypeCreditAlphaNum extends Asset {
   protected final String mCode;
   protected final String mIssuer;
 
-  public AssetTypeCreditAlphaNum(String code, String issuer) {
-    checkNotNull(code, "code cannot be null");
-    checkNotNull(issuer, "issuer cannot be null");
+  public AssetTypeCreditAlphaNum(@NonNull String code, @NonNull String issuer) {
     mCode = code;
     mIssuer = issuer;
   }
@@ -37,7 +34,7 @@ public String toString() {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(this.mCode, this.mIssuer);
+    return Objects.hash(this.mCode, this.mIssuer);
   }
 
   @Override

src/main/java/org/stellar/sdk/AssetTypePoolShare.java

@@ -1,6 +1,6 @@
 package org.stellar.sdk;
 
-import com.google.common.base.Objects;
+import java.util.Objects;
 
 /**
  * Represents Stellar liquidity pool share asset - <a
@@ -34,7 +34,7 @@ public boolean equals(Object object) {
       return false;
     }
 
-    return (Objects.equal(((AssetTypePoolShare) object).getPoolId(), poolId));
+    return (Objects.equals(((AssetTypePoolShare) object).getPoolId(), poolId));
   }
 
   @Override

src/main/java/org/stellar/sdk/BeginSponsoringFutureReservesOperation.java

@@ -1,8 +1,7 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
+import lombok.NonNull;
 import org.stellar.sdk.xdr.*;
 
 public class BeginSponsoringFutureReservesOperation extends Operation {
@@ -59,8 +58,9 @@ public Builder(String sponsoredId) {
      * @param sourceAccount The operation's source account.
      * @return Builder object so you can chain methods.
      */
-    public BeginSponsoringFutureReservesOperation.Builder setSourceAccount(String sourceAccount) {
-      mSourceAccount = checkNotNull(sourceAccount, "sourceAccount cannot be null");
+    public BeginSponsoringFutureReservesOperation.Builder setSourceAccount(
+        @NonNull String sourceAccount) {
+      mSourceAccount = sourceAccount;
       return this;
     }
 
@@ -77,7 +77,7 @@ public BeginSponsoringFutureReservesOperation build() {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(this.sponsoredId, this.getSourceAccount());
+    return Objects.hash(this.sponsoredId, this.getSourceAccount());
   }
 
   @Override
@@ -87,7 +87,7 @@ public boolean equals(Object object) {
     }
 
     BeginSponsoringFutureReservesOperation other = (BeginSponsoringFutureReservesOperation) object;
-    return Objects.equal(this.sponsoredId, other.sponsoredId)
-        && Objects.equal(this.getSourceAccount(), other.getSourceAccount());
+    return Objects.equals(this.sponsoredId, other.sponsoredId)
+        && Objects.equals(this.getSourceAccount(), other.getSourceAccount());
   }
 }

src/main/java/org/stellar/sdk/BumpSequenceOperation.java

@@ -1,8 +1,7 @@
 package org.stellar.sdk;
 
-import static com.google.common.base.Preconditions.checkNotNull;
-
-import com.google.common.base.Objects;
+import java.util.Objects;
+import lombok.NonNull;
 import org.stellar.sdk.xdr.BumpSequenceOp;
 import org.stellar.sdk.xdr.Int64;
 import org.stellar.sdk.xdr.OperationType;
@@ -65,8 +64,8 @@ public Builder(long bumpTo) {
      * @param sourceAccount The operation's source account.
      * @return Builder object so you can chain methods.
      */
-    public BumpSequenceOperation.Builder setSourceAccount(String sourceAccount) {
-      mSourceAccount = checkNotNull(sourceAccount, "sourceAccount cannot be null");
+    public BumpSequenceOperation.Builder setSourceAccount(@NonNull String sourceAccount) {
+      mSourceAccount = sourceAccount;
       return this;
     }
 
@@ -82,7 +81,7 @@ public BumpSequenceOperation build() {
 
   @Override
   public int hashCode() {
-    return Objects.hashCode(this.bumpTo, this.getSourceAccount());
+    return Objects.hash(this.bumpTo, this.getSourceAccount());
   }
 
   @Override
@@ -92,7 +91,7 @@ public boolean equals(Object object) {
     }
 
     BumpSequenceOperation other = (BumpSequenceOperation) object;
-    return Objects.equal(this.bumpTo, other.bumpTo)
-        && Objects.equal(this.getSourceAccount(), other.getSourceAccount());
+    return Objects.equals(this.bumpTo, other.bumpTo)
+        && Objects.equals(this.getSourceAccount(), other.getSourceAccount());
   }
 }