sdks/java/basys.sdk/src/main/java/org/eclipse/basyx/vab/protocol/basyx/connector/BaSyxConnector.java - basyx/basyx - Git at Google

 /*******************************************************************************
  * Copyright (C) 2021 the Eclipse BaSyx Authors
  *
  * This program and the accompanying materials are made
  * available under the terms of the Eclipse Public License 2.0
  * which is available at https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  ******************************************************************************/
 package org.eclipse.basyx.vab.protocol.basyx.connector;

 import java.io.IOException;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.nio.ByteBuffer;
 import java.nio.channels.SocketChannel;

 import org.eclipse.basyx.vab.exception.provider.ProviderException;
 import org.eclipse.basyx.vab.protocol.api.IBaSyxConnector;
 import org.eclipse.basyx.vab.protocol.basyx.CoderTools;
 import org.eclipse.basyx.vab.protocol.basyx.server.VABBaSyxTCPInterface;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;


 /**
  * BaSyx connector class
  *
  * @author kuhn, pschorn, schnicke
  *
  */
 public class BaSyxConnector implements IBaSyxConnector {

 	private Logger logger = LoggerFactory.getLogger(BaSyxConnector.class);
 	private InetSocketAddress serverSocketAddress;
 	private SocketChannel channelToProvider;


 	/**
 	 * Constructor that creates a connection.
 	 *
 	 * This constructor connects to port at name.
 	 */
 	public BaSyxConnector(String hostName, int port) {
 		// Base constructor
 		super();

 		// Exception handling
 		try {
 			// Resolve address
 			InetAddress       serverIPAddress     = InetAddress.getByName(hostName);
 			serverSocketAddress = new InetSocketAddress(serverIPAddress, port);
 		} catch (IOException e) {
 			// Print stack trace
 			logger.error("Exception in BaSyxConnector", e);
 		}
 	}

 	/**
 	 * Close connection
 	 */
 	private void closeConnection() {
 		// Try to close connection
 		try {
 			channelToProvider.close();
 		} catch (IOException e) {
 			// Print stack trace
 			logger.error("Exception in closeConnection", e);
 		}
 	}

 	/**
 	 * Invoke a BaSyx operation in a remote provider
 	 */
 	protected synchronized String invokeBaSyx(byte[] call) {
 		// Catch exceptions
 		try {
 			// Send byte array (BaSyx operation) via channel to provider
 			ByteBuffer txBuffer = ByteBuffer.wrap(call);

 			// Channel to provider
 			channelToProvider = SocketChannel.open();
 			// - Setup channel: set to blocking and connect to provider
 			channelToProvider.configureBlocking(true);
 			channelToProvider.connect(serverSocketAddress);

 			channelToProvider.write(txBuffer);

 			// Read response
 			// - Wait for leading 4 byte header that contains frame length
 			ByteBuffer rxBuffer1 = ByteBuffer.allocate(4);
 			// System.out.println("RX1");
 			readBytes(rxBuffer1, 4);
 			// System.out.println("RX1-d");
 			int frameSize = CoderTools.getInt32(rxBuffer1.array(), 0);

 			// Wait for frame to arrive
 			ByteBuffer rxBuffer2 = ByteBuffer.allocate(frameSize);
 			// System.out.println("RX2");
 			readBytes(rxBuffer2, frameSize);
 			// System.out.println("RX2-d");
 			byte[] rxFrame = rxBuffer2.array();

 			// Return received data

 			// Result check
 			if ((rxFrame == null) || (rxFrame.length < 2)) return null;

 			// - FIXME: Check result on position 0

 			// Extract response
 			int jsonResultLen = CoderTools.getInt32(rxFrame, 1);
 			String jsonResult = new String(rxFrame, 1 + 4, jsonResultLen);

 			// Close connection to prevent unused open channels
 			closeConnection();

 			// Return result
 			return jsonResult.toString();
 		} catch (IOException e) {
 			// Print stack trace
 			logger.error("Exception in invokeBaSyx", e);
 		}

 		// Indicate error
 		return null;
 	}


 	/**
 	 * Read a number of bytes
 	 */
 	protected void readBytes(ByteBuffer bytes, int expectedBytes) {
 		// Exception handling
 		try {
 			// System.out.println("-Reading:"+expectedBytes);
 			// Read bytes until buffer is full
 			while (bytes.position() < expectedBytes) {
 				// System.out.println("-Pos:"+bytes.position());
 				channelToProvider.read(bytes);
 			}
 			// System.out.println("-Read:"+expectedBytes);
 		} catch (IOException e) {
 			// Output exception
 			logger.error("Exception in readBytes", e);
 		}
 	}


 	/**
 	 * Invoke a BaSys get operation via HTTP
 	 */
 	@Override
 	public String getModelPropertyValue(String servicePath) {

 		byte[] call = createCall(servicePath, VABBaSyxTCPInterface.BASYX_GET);

 		// Invoke BaSyx call and return result
 		return invokeBaSyx(call);
 	}


 	/**
 	 * Invoke a Basys Set operation. Sets or overrides existing property, operation
 	 * or event.
 	 *
 	 * @throws ProviderException
 	 *             that carries the Exceptions thrown on the server
 	 */
 	@Override
 	public String setModelPropertyValue(String servicePath, String newValue) {

 		byte[] call = createCall(servicePath, newValue, VABBaSyxTCPInterface.BASYX_SET);

 		// Invoke BaSyx call and return result
 		return invokeBaSyx(call);
 	}


 	/**
 	 * Invoke a BaSys Create operation
 	 */
 	@Override
 	public String createValue(String servicePath, String newValue) throws ProviderException {

 		byte[] call = createCall(servicePath, newValue, VABBaSyxTCPInterface.BASYX_CREATE);

 		// Invoke BaSyx call and return result
 		return invokeBaSyx(call);
 	}


 	/**
 	 * Invoke a Basys invoke operation.
 	 */
 	@Override
 	public String invokeOperation(String servicePath, String parameters) throws ProviderException {

 		byte[] call = createCall(servicePath, parameters, VABBaSyxTCPInterface.BASYX_INVOKE);

 		// Invoke BaSyx call and return result
 		return invokeBaSyx(call);

 	}


 	/**
 	 * Invoke a Basys delete operation. Deletes any resource under the given path
 	 *
 	 * @throws ProviderException
 	 *             that carries the Exceptions thrown on the server
 	 */
 	@Override
 	public String deleteValue(String servicePath) throws ProviderException {

 		byte[] call = createCall(servicePath, VABBaSyxTCPInterface.BASYX_DELETE);

 		// Invoke BaSyx call and return result
 		return invokeBaSyx(call);
 	}


 	/**
 	 * Invoke a Basys delete operation. Deletes an entry from a map or collection by
 	 * the given key
 	 *
 	 * @throws ProviderException
 	 *             that carries the Exceptions thrown on the server
 	 */
 	@Override
 	public String deleteValue(String servicePath, String jsonObject) throws ProviderException {

 		byte[] call = createCall(servicePath, jsonObject, VABBaSyxTCPInterface.BASYX_DELETE);

 		// Invoke BaSyx call and return result
 		return invokeBaSyx(call);
 	}


 	/**
 	 * Create non-parameterized call that can be used as an argument to the
 	 * invokeBaSyx function
 	 *
 	 * @param servicePath
 	 * @param jsonObject
 	 * @return
 	 */
 	private byte[] createCall(String servicePath, byte callType) {
 		// Create call
 		byte[] call = new byte[4 + 1 + 4 + servicePath.length()];
 		// - Encode size does not include leading four bytes
 		CoderTools.setInt32(call, 0, call.length - 4);
 		// - Encode operation GET
 		CoderTools.setInt8(call, 4, callType);
 		// - Encode path length and path
 		CoderTools.setInt32(call, 5, servicePath.length());
 		CoderTools.setString(call, 9, servicePath);

 		return call;
 	}


 	/**
 	 * Create parameterized byte call that can be used as an argument to the
 	 * invokeBaSyx function
 	 *
 	 * @param servicePath
 	 * @param newValue
 	 * @param callType
 	 * @return
 	 */
 	private byte[] createCall(String servicePath, String newValue, byte callType) {

 		// Create call
 		byte[] call = new byte[4 + 1 + 4 + servicePath.length() + 4 + newValue.length()];
 		// - Encode size does not include leading four bytes
 		CoderTools.setInt32(call, 0, call.length - 4);
 		// - Encode operation SET
 		CoderTools.setInt8(call, 4, callType);
 		// - Encode path
 		CoderTools.setInt32(call, 5, servicePath.length());
 		CoderTools.setString(call, 9, servicePath);
 		// - Encode value
 		CoderTools.setInt32(call, 9 + servicePath.length(), newValue.length());
 		CoderTools.setString(call, 9 + servicePath.length() + 4, newValue);

 		return call;
 	}

 	/**
 	 * Get string representation of endpoint for given path for debugging.
 	 * @param path Requested path
 	 * @return String representing requested endpoint
 	 */
 	@Override
 	public String getEndpointRepresentation(String path) {
 		return "basyx://" + serverSocketAddress.getHostString() + ":" + serverSocketAddress.getPort() + "/" + path;
 	}
 }
	/*******************************************************************************
	* Copyright (C) 2021 the Eclipse BaSyx Authors
	*
	* This program and the accompanying materials are made
	* available under the terms of the Eclipse Public License 2.0
	* which is available at https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	******************************************************************************/
	package org.eclipse.basyx.vab.protocol.basyx.connector;

	import java.io.IOException;
	import java.net.InetAddress;
	import java.net.InetSocketAddress;
	import java.nio.ByteBuffer;
	import java.nio.channels.SocketChannel;

	import org.eclipse.basyx.vab.exception.provider.ProviderException;
	import org.eclipse.basyx.vab.protocol.api.IBaSyxConnector;
	import org.eclipse.basyx.vab.protocol.basyx.CoderTools;
	import org.eclipse.basyx.vab.protocol.basyx.server.VABBaSyxTCPInterface;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;



	/**
	* BaSyx connector class
	*
	* @author kuhn, pschorn, schnicke
	*
	*/
	public class BaSyxConnector implements IBaSyxConnector {

	private Logger logger = LoggerFactory.getLogger(BaSyxConnector.class);
	private InetSocketAddress serverSocketAddress;
	private SocketChannel channelToProvider;


	/**
	* Constructor that creates a connection.
	*
	* This constructor connects to port at name.
	*/
	public BaSyxConnector(String hostName, int port) {
	// Base constructor
	super();

	// Exception handling
	try {
	// Resolve address
	InetAddress serverIPAddress = InetAddress.getByName(hostName);
	serverSocketAddress = new InetSocketAddress(serverIPAddress, port);
	} catch (IOException e) {
	// Print stack trace
	logger.error("Exception in BaSyxConnector", e);
	}
	}

	/**
	* Close connection
	*/
	private void closeConnection() {
	// Try to close connection
	try {
	channelToProvider.close();
	} catch (IOException e) {
	// Print stack trace
	logger.error("Exception in closeConnection", e);
	}
	}

	/**
	* Invoke a BaSyx operation in a remote provider
	*/
	protected synchronized String invokeBaSyx(byte[] call) {
	// Catch exceptions
	try {
	// Send byte array (BaSyx operation) via channel to provider
	ByteBuffer txBuffer = ByteBuffer.wrap(call);

	// Channel to provider
	channelToProvider = SocketChannel.open();
	// - Setup channel: set to blocking and connect to provider
	channelToProvider.configureBlocking(true);
	channelToProvider.connect(serverSocketAddress);

	channelToProvider.write(txBuffer);

	// Read response
	// - Wait for leading 4 byte header that contains frame length
	ByteBuffer rxBuffer1 = ByteBuffer.allocate(4);
	// System.out.println("RX1");
	readBytes(rxBuffer1, 4);
	// System.out.println("RX1-d");
	int frameSize = CoderTools.getInt32(rxBuffer1.array(), 0);

	// Wait for frame to arrive
	ByteBuffer rxBuffer2 = ByteBuffer.allocate(frameSize);
	// System.out.println("RX2");
	readBytes(rxBuffer2, frameSize);
	// System.out.println("RX2-d");
	byte[] rxFrame = rxBuffer2.array();

	// Return received data

	// Result check
	if ((rxFrame == null) \|\| (rxFrame.length < 2)) return null;

	// - FIXME: Check result on position 0

	// Extract response
	int jsonResultLen = CoderTools.getInt32(rxFrame, 1);
	String jsonResult = new String(rxFrame, 1 + 4, jsonResultLen);

	// Close connection to prevent unused open channels
	closeConnection();

	// Return result
	return jsonResult.toString();
	} catch (IOException e) {
	// Print stack trace
	logger.error("Exception in invokeBaSyx", e);
	}

	// Indicate error
	return null;
	}


	/**
	* Read a number of bytes
	*/
	protected void readBytes(ByteBuffer bytes, int expectedBytes) {
	// Exception handling
	try {
	// System.out.println("-Reading:"+expectedBytes);
	// Read bytes until buffer is full
	while (bytes.position() < expectedBytes) {
	// System.out.println("-Pos:"+bytes.position());
	channelToProvider.read(bytes);
	}
	// System.out.println("-Read:"+expectedBytes);
	} catch (IOException e) {
	// Output exception
	logger.error("Exception in readBytes", e);
	}
	}


	/**
	* Invoke a BaSys get operation via HTTP
	*/
	@Override
	public String getModelPropertyValue(String servicePath) {

	byte[] call = createCall(servicePath, VABBaSyxTCPInterface.BASYX_GET);

	// Invoke BaSyx call and return result
	return invokeBaSyx(call);
	}


	/**
	* Invoke a Basys Set operation. Sets or overrides existing property, operation
	* or event.
	*
	* @throws ProviderException
	* that carries the Exceptions thrown on the server
	*/
	@Override
	public String setModelPropertyValue(String servicePath, String newValue) {

	byte[] call = createCall(servicePath, newValue, VABBaSyxTCPInterface.BASYX_SET);

	// Invoke BaSyx call and return result
	return invokeBaSyx(call);
	}


	/**
	* Invoke a BaSys Create operation
	*/
	@Override
	public String createValue(String servicePath, String newValue) throws ProviderException {

	byte[] call = createCall(servicePath, newValue, VABBaSyxTCPInterface.BASYX_CREATE);

	// Invoke BaSyx call and return result
	return invokeBaSyx(call);
	}


	/**
	* Invoke a Basys invoke operation.
	*/
	@Override
	public String invokeOperation(String servicePath, String parameters) throws ProviderException {

	byte[] call = createCall(servicePath, parameters, VABBaSyxTCPInterface.BASYX_INVOKE);

	// Invoke BaSyx call and return result
	return invokeBaSyx(call);

	}


	/**
	* Invoke a Basys delete operation. Deletes any resource under the given path
	*
	* @throws ProviderException
	* that carries the Exceptions thrown on the server
	*/
	@Override
	public String deleteValue(String servicePath) throws ProviderException {

	byte[] call = createCall(servicePath, VABBaSyxTCPInterface.BASYX_DELETE);

	// Invoke BaSyx call and return result
	return invokeBaSyx(call);
	}


	/**
	* Invoke a Basys delete operation. Deletes an entry from a map or collection by
	* the given key
	*
	* @throws ProviderException
	* that carries the Exceptions thrown on the server
	*/
	@Override
	public String deleteValue(String servicePath, String jsonObject) throws ProviderException {

	byte[] call = createCall(servicePath, jsonObject, VABBaSyxTCPInterface.BASYX_DELETE);

	// Invoke BaSyx call and return result
	return invokeBaSyx(call);
	}


	/**
	* Create non-parameterized call that can be used as an argument to the
	* invokeBaSyx function
	*
	* @param servicePath
	* @param jsonObject
	* @return
	*/
	private byte[] createCall(String servicePath, byte callType) {
	// Create call
	byte[] call = new byte[4 + 1 + 4 + servicePath.length()];
	// - Encode size does not include leading four bytes
	CoderTools.setInt32(call, 0, call.length - 4);
	// - Encode operation GET
	CoderTools.setInt8(call, 4, callType);
	// - Encode path length and path
	CoderTools.setInt32(call, 5, servicePath.length());
	CoderTools.setString(call, 9, servicePath);

	return call;
	}


	/**
	* Create parameterized byte call that can be used as an argument to the
	* invokeBaSyx function
	*
	* @param servicePath
	* @param newValue
	* @param callType
	* @return
	*/
	private byte[] createCall(String servicePath, String newValue, byte callType) {

	// Create call
	byte[] call = new byte[4 + 1 + 4 + servicePath.length() + 4 + newValue.length()];
	// - Encode size does not include leading four bytes
	CoderTools.setInt32(call, 0, call.length - 4);
	// - Encode operation SET
	CoderTools.setInt8(call, 4, callType);
	// - Encode path
	CoderTools.setInt32(call, 5, servicePath.length());
	CoderTools.setString(call, 9, servicePath);
	// - Encode value
	CoderTools.setInt32(call, 9 + servicePath.length(), newValue.length());
	CoderTools.setString(call, 9 + servicePath.length() + 4, newValue);

	return call;
	}

	/**
	* Get string representation of endpoint for given path for debugging.
	* @param path Requested path
	* @return String representing requested endpoint
	*/
	@Override
	public String getEndpointRepresentation(String path) {
	return "basyx://" + serverSocketAddress.getHostString() + ":" + serverSocketAddress.getPort() + "/" + path;
	}
	}