Added "X-API-VERSION" header support in POST /transactions/process.

Default is version "1". If version "2" is specified, the API will return the full transaction JSON on success, rather than just "true".

Example usage:

curl -X POST "http://localhost:12391/transactions/process" -H  "X-API-VERSION: 2" -d "signedTransactionBytesHere"

src/main/java/org/qortal/api/ApiRequest.java

@@ -3,6 +3,7 @@ package org.qortal.api;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UnsupportedEncodingException;
+import java.io.Writer;
 import java.net.HttpURLConnection;
 import java.net.InetSocketAddress;
 import java.net.Socket;
@@ -20,14 +21,12 @@ import javax.net.ssl.SNIHostName;
 import javax.net.ssl.SNIServerName;
 import javax.net.ssl.SSLParameters;
 import javax.net.ssl.SSLSocket;
-import javax.xml.bind.JAXBContext;
-import javax.xml.bind.JAXBException;
-import javax.xml.bind.UnmarshalException;
-import javax.xml.bind.Unmarshaller;
+import javax.xml.bind.*;
 import javax.xml.transform.stream.StreamSource;
 
 import org.eclipse.persistence.exceptions.XMLMarshalException;
 import org.eclipse.persistence.jaxb.JAXBContextFactory;
+import org.eclipse.persistence.jaxb.MarshallerProperties;
 import org.eclipse.persistence.jaxb.UnmarshallerProperties;
 
 public class ApiRequest {
@@ -107,6 +106,36 @@ public class ApiRequest {
 		}
 	}
 
+	private static Marshaller createMarshaller(Class<?> objectClass) {
+		try {
+			// Create JAXB context aware of object's class
+			JAXBContext jc = JAXBContextFactory.createContext(new Class[] { objectClass }, null);
+
+			// Create marshaller
+			Marshaller marshaller = jc.createMarshaller();
+
+			// Set the marshaller media type to JSON
+			marshaller.setProperty(MarshallerProperties.MEDIA_TYPE, "application/json");
+
+			// Tell marshaller not to include JSON root element in the output
+			marshaller.setProperty(MarshallerProperties.JSON_INCLUDE_ROOT, false);
+
+			return marshaller;
+		} catch (JAXBException e) {
+			throw new RuntimeException("Unable to create websocket marshaller", e);
+		}
+	}
+
+	public static void marshall(Writer writer, Object object) throws IOException {
+		Marshaller marshaller = createMarshaller(object.getClass());
+
+		try {
+			marshaller.marshal(object, writer);
+		} catch (JAXBException e) {
+			throw new IOException("Unable to create marshall object for websocket", e);
+		}
+	}
+
 	public static String getParamsString(Map<String, String> params) {
 		StringBuilder result = new StringBuilder();
 

src/main/java/org/qortal/api/ApiService.java

@@ -13,6 +13,7 @@ import java.security.SecureRandom;
 
 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
+import javax.servlet.http.HttpServletRequest;
 
 import org.eclipse.jetty.http.HttpVersion;
 import org.eclipse.jetty.rewrite.handler.RedirectPatternRule;
@@ -50,6 +51,8 @@ public class ApiService {
 	private Server server;
 	private ApiKey apiKey;
 
+	public static final String API_VERSION_HEADER = "X-API-VERSION";
+
 	private ApiService() {
 		this.config = new ResourceConfig();
 		this.config.packages("org.qortal.api.resource", "org.qortal.api.restricted.resource");
@@ -229,4 +232,19 @@ public class ApiService {
 		this.server = null;
 	}
 
+	public static int getApiVersion(HttpServletRequest request) {
+		// Get API version
+		String apiVersionString = request.getHeader(API_VERSION_HEADER);
+		if (apiVersionString == null) {
+			// Try query string - this is needed to avoid a CORS preflight. See: https://stackoverflow.com/a/43881141
+			apiVersionString = request.getParameter("apiVersion");
+		}
+
+		int apiVersion = 1;
+		if (apiVersionString != null) {
+			apiVersion = Integer.parseInt(apiVersionString);
+		}
+		return apiVersion;
+	}
+
 }

src/main/java/org/qortal/api/resource/TransactionsResource.java

@@ -9,6 +9,8 @@ import io.swagger.v3.oas.annotations.parameters.RequestBody;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.tags.Tag;
 
+import java.io.IOException;
+import java.io.StringWriter;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
@@ -18,19 +20,12 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.locks.ReentrantLock;
 
 import javax.servlet.http.HttpServletRequest;
-import javax.ws.rs.GET;
-import javax.ws.rs.POST;
-import javax.ws.rs.Path;
-import javax.ws.rs.PathParam;
-import javax.ws.rs.QueryParam;
+import javax.ws.rs.*;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 
 import org.qortal.account.PrivateKeyAccount;
-import org.qortal.api.ApiError;
-import org.qortal.api.ApiErrors;
-import org.qortal.api.ApiException;
-import org.qortal.api.ApiExceptionFactory;
+import org.qortal.api.*;
 import org.qortal.api.model.SimpleTransactionSignRequest;
 import org.qortal.controller.Controller;
 import org.qortal.controller.LiteNode;
@@ -709,7 +704,7 @@ public class TransactionsResource {
 		),
 		responses = {
 			@ApiResponse(
-				description = "true if accepted, false otherwise",
+				description = "For API version 1, this returns true if accepted.\nFor API version 2, the transactionData is returned as a JSON string if accepted.",
 				content = @Content(
 					mediaType = MediaType.TEXT_PLAIN,
 					schema = @Schema(
@@ -722,7 +717,9 @@ public class TransactionsResource {
 	@ApiErrors({
 		ApiError.BLOCKCHAIN_NEEDS_SYNC, ApiError.INVALID_SIGNATURE, ApiError.INVALID_DATA, ApiError.TRANSFORMATION_ERROR, ApiError.REPOSITORY_ISSUE
 	})
-	public String processTransaction(String rawBytes58) {
+	public String processTransaction(String rawBytes58, @HeaderParam(ApiService.API_VERSION_HEADER) String apiVersionHeader) {
+		int apiVersion = ApiService.getApiVersion(request);
+
 		// Only allow a transaction to be processed if our latest block is less than 60 minutes old
 		// If older than this, we should first wait until the blockchain is synced
 		final Long minLatestBlockTimestamp = NTP.getTime() - (60 * 60 * 1000L);
@@ -759,13 +756,27 @@ public class TransactionsResource {
 				blockchainLock.unlock();
 			}
 
-			return "true";
+			switch (apiVersion) {
+				case 1:
+					return "true";
+
+				case 2:
+				default:
+					// Marshall transactionData to string
+					StringWriter stringWriter = new StringWriter();
+					ApiRequest.marshall(stringWriter, transactionData);
+					return stringWriter.toString();
+			}
+
+
 		} catch (NumberFormatException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_DATA, e);
 		} catch (DataException e) {
 			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e);
 		} catch (InterruptedException e) {
 			throw createTransactionInvalidException(request, ValidationResult.NO_BLOCKCHAIN_LOCK);
+		} catch (IOException e) {
+			throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.TRANSFORMATION_ERROR, e);
 		}
 	}