Added support for calling Soroban RPC server.

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

@@ -85,6 +85,15 @@ public Network getNetwork() {
     return mNetwork;
   }
 
+  /**
+   * Gets the {@link AccountConverter} for this transaction.
+   *
+   * @return the {@link AccountConverter} object
+   */
+  public AccountConverter getAccountConverter() {
+    return accountConverter;
+  }
+
   /**
    * Gets read only list(immutable) of the signatures on transaction.
    *

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

@@ -0,0 +1,15 @@
+package org.stellar.sdk;
+
+import lombok.Getter;
+
+/** Exception thrown when trying to load an account that doesn't exist on the Stellar network. */
+@Getter
+public class AccountNotFoundException extends Exception {
+  // The account that was not found.
+  private final String accountId;
+
+  public AccountNotFoundException(String accountId) {
+    super("Account not found, accountId: " + accountId);
+    this.accountId = accountId;
+  }
+}

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

@@ -13,6 +13,10 @@ public class Network {
   public static final Network PUBLIC =
       new Network("Public Global Stellar Network ; September 2015");
   public static final Network TESTNET = new Network("Test SDF Network ; September 2015");
+  public static final Network FUTURENET = new Network("Test SDF Future Network ; October 2022");
+  public static final Network STANDALONE = new Network("Standalone Network ; February 2017");
+  public static final Network SANDBOX =
+      new Network("Local Sandbox Stellar Network ; September 2022");
 
   private final String networkPassphrase;
 

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

@@ -0,0 +1,17 @@
+package org.stellar.sdk;
+
+import lombok.Getter;
+import org.stellar.sdk.responses.sorobanrpc.SimulateTransactionResponse;
+
+/** Exception thrown when preparing a transaction failed. */
+@Getter
+public class PrepareTransactionException extends Exception {
+  // The response returned by the Soroban-RPC instance when simulating the transaction.
+  private final SimulateTransactionResponse simulateTransactionResponse;
+
+  public PrepareTransactionException(
+      String message, SimulateTransactionResponse simulateTransactionResponse) {
+    super(message);
+    this.simulateTransactionResponse = simulateTransactionResponse;
+  }
+}

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

@@ -388,4 +388,20 @@ public Builder(TransactionBuilderAccount sourceAccount, Network network) {
       super(sourceAccount, network);
     }
   }
+
+  /**
+   * Returns true if this transaction is a Soroban transaction.
+   *
+   * @return true if this transaction is a Soroban transaction.
+   */
+  public boolean isSorobanTransaction() {
+    if (mOperations.length != 1) {
+      return false;
+    }
+
+    Operation op = mOperations[0];
+    return op instanceof InvokeHostFunctionOperation
+        || op instanceof BumpSequenceOperation
+        || op instanceof RestoreFootprintOperation;
+  }
 }

src/main/java/org/stellar/sdk/requests/sorobanrpc/EventFilterType.java

@@ -0,0 +1,13 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import com.google.gson.annotations.SerializedName;
+
+/** Represents the type of event. */
+public enum EventFilterType {
+  @SerializedName("system")
+  SYSTEM,
+  @SerializedName("contract")
+  CONTRACT,
+  @SerializedName("diagnostic")
+  DIAGNOSTIC
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/GetEventsRequest.java

@@ -0,0 +1,43 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import java.util.Collection;
+import lombok.Builder;
+import lombok.NonNull;
+import lombok.Singular;
+import lombok.Value;
+
+/**
+ * Request for JSON-RPC method getEvents.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getEvents#parameters"
+ *     target="_blank">getEvents documentation</a>
+ */
+@Value
+@Builder(toBuilder = true)
+public class GetEventsRequest {
+  @NonNull String startLedger;
+
+  @Singular("filter")
+  Collection<EventFilter> filters;
+
+  PaginationOptions pagination;
+
+  @Value
+  @Builder(toBuilder = true)
+  public static class PaginationOptions {
+    Long limit;
+
+    String cursor;
+  }
+
+  @Builder(toBuilder = true)
+  @Value
+  public static class EventFilter {
+    EventFilterType type;
+
+    Collection<String> contractIds;
+
+    @Singular("topic")
+    Collection<Collection<String>> topics;
+  }
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/GetLedgerEntriesRequest.java

@@ -0,0 +1,17 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import java.util.Collection;
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Request for JSON-RPC method getLedgerEntries.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getLedgerEntries#parameters"
+ *     target="_blank">getLedgerEntries documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class GetLedgerEntriesRequest {
+  Collection<String> keys;
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/GetTransactionRequest.java

@@ -0,0 +1,16 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Request for JSON-RPC method getTransaction.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getTransaction#parameters"
+ *     target="_blank">getTransaction documentation</a>
+ */
+@Value
+@AllArgsConstructor
+public class GetTransactionRequest {
+  String hash;
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/SendTransactionRequest.java

@@ -0,0 +1,16 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Request for JSON-RPC method sendTransaction.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/sendTransaction#parameters"
+ *     target="_blank">sendTransaction documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class SendTransactionRequest {
+  String transaction;
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/SimulateTransactionRequest.java

@@ -0,0 +1,16 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Request for JSON-RPC method simulateTransaction.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/simulateTransaction#parameters"
+ *     target="_blank">simulateTransaction documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class SimulateTransactionRequest {
+  String transaction;
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/SorobanRpcErrorResponse.java

@@ -0,0 +1,25 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import lombok.Getter;
+
+/**
+ * Throws when Soroban-RPC instance responds with error.
+ *
+ * @see <a href="https://www.jsonrpc.org/specification#error_object" target="_blank">JSON-RPC 2.0
+ *     Specification - Error object<a>
+ */
+@Getter
+public class SorobanRpcErrorResponse extends Exception {
+  private final Integer code;
+
+  private final String message;
+
+  private final String data;
+
+  public SorobanRpcErrorResponse(Integer code, String message, String data) {
+    super(message);
+    this.code = code;
+    this.message = message;
+    this.data = data;
+  }
+}

src/main/java/org/stellar/sdk/requests/sorobanrpc/SorobanRpcRequest.java

@@ -0,0 +1,24 @@
+package org.stellar.sdk.requests.sorobanrpc;
+
+import com.google.gson.annotations.SerializedName;
+import lombok.RequiredArgsConstructor;
+import lombok.Value;
+
+/**
+ * Represent the request sent to Soroban-RPC.
+ *
+ * @see <a href="https://www.jsonrpc.org/specification#request_object" target="_blank">JSON-RPC 2.0
+ *     Specification - Request object<a>
+ */
+@RequiredArgsConstructor
+@Value
+public class SorobanRpcRequest<T> {
+  @SerializedName("jsonrpc")
+  String jsonRpc = "2.0";
+
+  String id;
+
+  String method;
+
+  T params;
+}

src/main/java/org/stellar/sdk/responses/GsonSingleton.java

@@ -1,5 +1,6 @@
 package org.stellar.sdk.responses;
 
+import com.google.common.collect.ImmutableList;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.reflect.TypeToken;
@@ -68,6 +69,7 @@ public static Gson getInstance() {
               .registerTypeAdapter(
                   claimableBalancePageType.getType(),
                   new PageDeserializer<ClaimableBalanceResponse>(claimableBalancePageType))
+              .registerTypeAdapter(ImmutableList.class, new ImmutableListDeserializer())
               .create();
     }
     return instance;

src/main/java/org/stellar/sdk/responses/sorobanrpc/GetEventsResponse.java

@@ -0,0 +1,48 @@
+package org.stellar.sdk.responses.sorobanrpc;
+
+import com.google.common.collect.ImmutableList;
+import lombok.AllArgsConstructor;
+import lombok.Value;
+import org.stellar.sdk.requests.sorobanrpc.EventFilterType;
+
+/**
+ * Response for JSON-RPC method getEvents.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getEvents#returns"
+ *     target="_blank">getEvents documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class GetEventsResponse {
+  ImmutableList<EventInfo> events;
+
+  Long latestLedger;
+
+  @AllArgsConstructor
+  @Value
+  public static class EventInfo {
+    EventFilterType type;
+
+    Integer ledger;
+
+    String ledgerClosedAt;
+
+    String contractId;
+
+    String id;
+
+    String pagingToken;
+
+    ImmutableList<String> topic;
+
+    EventInfoValue value;
+
+    Boolean inSuccessfulContractCall;
+  }
+
+  @AllArgsConstructor
+  @Value
+  public static class EventInfoValue {
+    String xdr;
+  }
+}

src/main/java/org/stellar/sdk/responses/sorobanrpc/GetHealthResponse.java

@@ -0,0 +1,16 @@
+package org.stellar.sdk.responses.sorobanrpc;
+
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Response for JSON-RPC method getHealth.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getHealth#returns"
+ *     target="_blank">getHealth documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class GetHealthResponse {
+  String status;
+}

src/main/java/org/stellar/sdk/responses/sorobanrpc/GetLatestLedgerResponse.java

@@ -0,0 +1,20 @@
+package org.stellar.sdk.responses.sorobanrpc;
+
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Response for JSON-RPC method getLatestLedger.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getLatestLedger#returns"
+ *     target="_blank">getLatestLedger documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class GetLatestLedgerResponse {
+  String id;
+
+  Integer protocolVersion;
+
+  Integer sequence;
+}

src/main/java/org/stellar/sdk/responses/sorobanrpc/GetLedgerEntriesResponse.java

@@ -0,0 +1,31 @@
+package org.stellar.sdk.responses.sorobanrpc;
+
+import com.google.common.collect.ImmutableList;
+import com.google.gson.annotations.SerializedName;
+import lombok.AllArgsConstructor;
+import lombok.Value;
+
+/**
+ * Response for JSON-RPC method getLedgerEntries.
+ *
+ * @see <a href="https://soroban.stellar.org/api/methods/getLedgerEntries#returns"
+ *     target="_blank">getLedgerEntries documentation</a>
+ */
+@AllArgsConstructor
+@Value
+public class GetLedgerEntriesResponse {
+  ImmutableList<LedgerEntryResult> entries;
+
+  Long latestLedger;
+
+  @AllArgsConstructor
+  @Value
+  public static class LedgerEntryResult {
+    String key;
+
+    String xdr;
+
+    @SerializedName("lastModifiedLedgerSeq")
+    Long lastModifiedLedger;
+  }
+}