feat: implement automatic chunking for FileCreate and FileUpdate

sdk/src/main/java/com/hedera/hashgraph/sdk/ChunkedTransaction.java

@@ -118,6 +118,51 @@ T setData(String text) {
         // noinspection unchecked
         return (T) this;
     }
+
+    /**
+	 * Checks whether {@code innerSignedTransactions} is not empty.
+	 *
+	 * @return {@code true} if {@code innerSignedTransactions} is not empty; otherwise {@code false}
+	 */
+    boolean hasInnerSignedTransactions(){
+    	return (!innerSignedTransactions.isEmpty());
+    }
+
+    /**
+	 * Assigns the data via {@code innerSignedTransactions}.
+	 *
+	 * @return {@code this}
+	 * @throws IllegalArgumentException if {@code innerSignedTransactions} is empty
+	 */
+    T setDataFromInnerSignedTransactions() {
+        if (!innerSignedTransactions.isEmpty()) {
+            try {
+                for (var i = 0; i < innerSignedTransactions.size(); i += nodeAccountIds.isEmpty() ? 1 : nodeAccountIds.size()) {
+                    ByteString content = extractContents(TransactionBody.parseFrom(innerSignedTransactions.get(i).getBodyBytes()));
+                    data = data.concat(content);
+                }
+                return (T) this;
+            } catch (InvalidProtocolBufferException exc) {
+                throw new IllegalArgumentException(exc.getMessage());
+            }
+        }
+        return (T) this;
+    }
+
+	/**
+	 * Extracts the content bytes from a {@link TransactionBody}.
+	 * <p>
+	 * This is a template method used by
+	 * {@link #setDataFromInnerSignedTransactions()} to consolidate content from
+	 * multiple inner signed transactions. Because different transaction types
+	 * (e.g., FileCreate, FileUpdate, FileAppend) store their content in different
+	 * fields of the protobuf body, child classes must implement this method to
+	 * specify the correct field to extract.
+	 *
+	 * @param body The protobuf transaction body to extract data from.
+	 * @return The {@link ByteString} representing the content of the transaction.
+	 */
+     protected abstract ByteString extractContents(TransactionBody body);
 
     /**
      * Retrieve the maximum number of chunks.

sdk/src/main/java/com/hedera/hashgraph/sdk/FileAppendTransaction.java

@@ -186,23 +186,17 @@ void initFromTransactionBody() {
             fileId = FileId.fromProtobuf(body.getFileID());
         }
 
-        if (!innerSignedTransactions.isEmpty()) {
-            try {
-                for (var i = 0;
-                        i < innerSignedTransactions.size();
-                        i += nodeAccountIds.isEmpty() ? 1 : nodeAccountIds.size()) {
-                    data = data.concat(TransactionBody.parseFrom(
-                                    innerSignedTransactions.get(i).getBodyBytes())
-                            .getFileAppend()
-                            .getContents());
-                }
-            } catch (InvalidProtocolBufferException exc) {
-                throw new IllegalArgumentException(exc.getMessage());
-            }
+        if (hasInnerSignedTransactions()) {
+           setDataFromInnerSignedTransactions();
         } else {
-            data = body.getContents();
+        	setData(body.getContents().toByteArray());
         }
     }
+
+    @Override
+    protected ByteString extractContents(TransactionBody body) {
+        return body.getFileAppend().getContents();
+    }
 
     /**
      * Build the transaction body.
@@ -214,7 +208,7 @@ FileAppendTransactionBody.Builder build() {
         if (fileId != null) {
             builder.setFileID(fileId.toProtobuf());
         }
-        builder.setContents(data);
+        builder.setContents(getData());
 
         return builder;
     }

sdk/src/main/java/com/hedera/hashgraph/sdk/FileCreateTransaction.java

@@ -7,12 +7,11 @@
 import com.hedera.hashgraph.sdk.proto.FileServiceGrpc;
 import com.hedera.hashgraph.sdk.proto.SchedulableTransactionBody;
 import com.hedera.hashgraph.sdk.proto.TransactionBody;
+import com.hedera.hashgraph.sdk.proto.TransactionID;
 import com.hedera.hashgraph.sdk.proto.TransactionResponse;
 import io.grpc.MethodDescriptor;
-import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.time.Instant;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -23,7 +22,7 @@
  * Create a new file.
  *
  * If successful, the new file SHALL contain the (possibly empty) content
- * provided in the `contents` field.<br/>
+ * provided in the `data` field in {@link ChunkedTransaction}.<br/>
  * When the current consensus time exceeds the `expirationTime` value, the
  * network SHALL expire the file, and MAY archive the state entry.
  *
@@ -60,7 +59,7 @@
  * After the file is created, the FileID for it SHALL be returned in the
  * transaction receipt, and SHALL be recorded in the transaction record.
  */
-public final class FileCreateTransaction extends Transaction<FileCreateTransaction> {
+public final class FileCreateTransaction extends ChunkedTransaction<FileCreateTransaction> {
 
     @Nullable
     private Instant expirationTime = null;
@@ -70,7 +69,6 @@ public final class FileCreateTransaction extends Transaction<FileCreateTransacti
     @Nullable
     private KeyList keys = null;
 
-    private byte[] contents = {};
     private String fileMemo = "";
 
     /**
@@ -175,61 +173,51 @@ public FileCreateTransaction setKeys(Key... keys) {
     }
 
     /**
-     * Create the byte string.
-     *
-     * @return                          byte string representation
-     */
-    public ByteString getContents() {
-        return ByteString.copyFrom(contents);
-    }
+	 * Extract the files contents as a byte string.
+	 *
+	 * @return the files contents as a byte string
+	 */
+	public ByteString getContents() {
+		return getData();
+	}
 
     /**
-     * <p>Set the given byte array as the file's contents.
-     *
-     * <p>This may be omitted to create an empty file.
-     *
-     * <p>Note that total size for a given transaction is limited to 6KiB (as of March 2020) by the
-     * network; if you exceed this you may receive a {@link PrecheckStatusException}
-     * with {@link com.hedera.hashgraph.sdk.Status#TRANSACTION_OVERSIZE}.
-     *
-     * <p>In this case, you can use {@link FileAppendTransaction}, which automatically breaks the contents
-     * into chunks for you, to append contents of arbitrary size.
-     *
-     * @param bytes the contents of the file.
-     * @return {@code this}
-     */
-    public FileCreateTransaction setContents(byte[] bytes) {
-        requireNotFrozen();
-        Objects.requireNonNull(bytes);
-        contents = Arrays.copyOf(bytes, bytes.length);
-        return this;
-    }
+	 * <p>
+	 * Set the given byte array as the file's contents.
+	 *
+	 * <p>
+	 * This may be omitted to create an empty file.
+	 *
+	 * @param bytes the contents of the file.
+	 * @return {@code this}
+	 */
+	public FileCreateTransaction setContents(byte[] bytes) {
+		requireNotFrozen();
+		Objects.requireNonNull(bytes);
+		return setData(bytes);
+	}
 
     /**
-     * <p>Encode the given {@link String} as UTF-8 and set it as the file's contents.
-     *
-     * <p>This may be omitted to create an empty file.
-     *
-     * <p>The string can later be recovered from {@link FileContentsQuery#execute(Client)}
-     * via {@link String#String(byte[], java.nio.charset.Charset)} using
-     * {@link java.nio.charset.StandardCharsets#UTF_8}.
-     *
-     * <p>Note that total size for a given transaction is limited to 6KiB (as of March 2020) by the
-     * network; if you exceed this you may receive a {@link PrecheckStatusException}
-     * with {@link com.hedera.hashgraph.sdk.Status#TRANSACTION_OVERSIZE}.
-     *
-     * <p>In this case, you can use {@link FileAppendTransaction}, which automatically breaks the contents
-     * into chunks for you, to append contents of arbitrary size.
-     *
-     * @param text the contents of the file.
-     * @return {@code this}
-     */
-    public FileCreateTransaction setContents(String text) {
-        requireNotFrozen();
-        Objects.requireNonNull(text);
-        contents = text.getBytes(StandardCharsets.UTF_8);
-        return this;
-    }
+	 * <p>
+	 * Encode the given {@link String} as UTF-8 and set it as the file's contents.
+	 *
+	 * <p>
+	 * This may be omitted to create an empty file.
+	 *
+	 * <p>
+	 * The string can later be recovered from
+	 * {@link FileContentsQuery#execute(Client)} via
+	 * {@link String#String(byte[], java.nio.charset.Charset)} using
+	 * {@link java.nio.charset.StandardCharsets#UTF_8}.
+	 *
+	 * @param text the contents of the file.
+	 * @return {@code this}
+	 */
+	public FileCreateTransaction setContents(String text) {
+		requireNotFrozen();
+		Objects.requireNonNull(text);
+		return setData(text);
+	}
 
     /**
      * Extract the file's memo field.
@@ -274,8 +262,18 @@ void initFromTransactionBody() {
         if (body.hasKeys()) {
             keys = KeyList.fromProtobuf(body.getKeys(), null);
         }
-        contents = body.getContents().toByteArray();
         fileMemo = body.getMemo();
+
+        if (hasInnerSignedTransactions()) {
+           setDataFromInnerSignedTransactions();
+        } else {
+        	setData(body.getContents().toByteArray());
+        }
+    }
+
+    @Override
+    protected ByteString extractContents(TransactionBody body) {
+        return body.getFileCreate().getContents();
     }
 
     /**
@@ -295,11 +293,22 @@ FileCreateTransactionBody.Builder build() {
         if (keys != null) {
             builder.setKeys(keys.toProtobuf());
         }
-        builder.setContents(ByteString.copyFrom(contents));
+        builder.setContents(getData());
         builder.setMemo(fileMemo);
 
         return builder;
     }
+
+    @Override
+    void onFreezeChunk(
+            TransactionBody.Builder body,
+            @Nullable TransactionID initialTransactionId,
+            int startIndex,
+            int endIndex,
+            int chunk,
+            int total) {
+        body.setFileCreate(build().setContents(data.substring(startIndex, endIndex)));
+    }
 
     @Override
     void onFreeze(TransactionBody.Builder bodyBuilder) {