Files
XPlaneConnectCSP/Java/src/XPlaneConnect.java

601 lines
21 KiB
Java

package gov.nasa.xpc;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.lang.AutoCloseable;
import java.net.*;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.charset.StandardCharsets;
import java.util.Arrays;
/**
* Represents a client that can connect to and interact with the X-Plane Connect plugin.
*
* @author Jason Watkins
* @version 0.1
* @since 2015-03-31
*/
public class XPlaneConnect implements AutoCloseable
{
private static int clientNum;
private DatagramSocket outSocket;
private DatagramSocket inSocket;
private InetAddress xplaneAddr;
private int xplanePort;
/**
* Gets the port on which the client receives data from the plugin.
*
* @return The incoming port number.
*/
public int getRecvPort() { return inSocket.getLocalPort(); }
/**
* Gets the port on which the client sends data to X-Plane.
*
* @return The outgoing port number.
*/
public int getXPlanePort() { return xplanePort; }
/**
* Sets the port on which the client sends data to X-Plane
*
* @param port The new outgoing port number.
* @throws IllegalArgumentException If {@code port} is not a valid port number.
*/
public void setXPlanePort(int port)
{
if(port < 0 || port >= 0xFFFF)
{
throw new IllegalArgumentException("Invalid port (must be non-negative and less than 65536).");
}
xplanePort = port;
}
/**
* Gets the hostname of the X-Plane host.
*
* @return The hostname of the X-Plane host.
*/
public String getXPlaneAddr() { return xplaneAddr.getHostAddress(); }
/**
* Sets the hostname of the X-Plane host.
*
* @param host The new hostname of the X-Plane host machine.
* @throws UnknownHostException {@code host} is not valid.
*/
public void setXplaneAddr(String host) throws UnknownHostException
{
xplaneAddr = InetAddress.getByName(host);
}
/**
* Initializes a new instance of the {@code XPlaneConnect} class using default ports and assuming X-Plane is running on the
* local machine.
*
* @throws SocketException If this instance is unable to bind to the default receive port.
*/
public XPlaneConnect() throws SocketException
{
this(100);
}
/**
* Initializes a new instance of the {@code XPlaneConnect} class with the specified timeout using default ports and
* assuming X-Plane is running on the local machine.
*
* @param timeout The time, in milliseconds, after which read attempts will timeout.
* @throws SocketException If this instance is unable to bind to the default receive port.
*/
public XPlaneConnect(int timeout) throws SocketException
{
this.inSocket = new DatagramSocket(49008);
this.outSocket = new DatagramSocket(50000 + ++clientNum);
this.xplaneAddr = InetAddress.getLoopbackAddress();
this.xplanePort = 49009;
this.inSocket.setSoTimeout(timeout);
}
/**
* Initializes a new instance of the {@code XPlaneConnect} class using the specified ports and X-Plane host.
*
* @param port The port on which the X-Plane Connect plugin is sending data.
* @param xplaneHost The network host on which X-Plane is running.
* @param xplanePort The port on which the X-Plane Connect plugin is listening.
* @throws java.net.SocketException If this instance is unable to bind to the specified port.
* @throws java.net.UnknownHostException If the specified hostname can not be resolved.
*/
public XPlaneConnect(int port, String xplaneHost, int xplanePort)
throws java.net.SocketException, java.net.UnknownHostException
{
this(port, xplaneHost, xplanePort, 100);
}
/**
* Initializes a new instance of the {@code XPlaneConnect} class using the specified ports, hostname, and timeout.
*
* @param port The port on which the X-Plane Connect plugin is sending data.
* @param xplaneHost The network host on which X-Plane is running.
* @param xplanePort The port on which the X-Plane Connect plugin is listening.
* @param timeout The time, in milliseconds, after which read attempts will timeout.
* @throws java.net.SocketException If this instance is unable to bind to the specified port.
* @throws java.net.UnknownHostException If the specified hostname can not be resolved.
*/
public XPlaneConnect(int port, String xplaneHost, int xplanePort, int timeout)
throws java.net.SocketException, java.net.UnknownHostException
{
this.inSocket = new DatagramSocket(port);
this.outSocket = new DatagramSocket(50000 + ++clientNum);
this.xplaneAddr = InetAddress.getByName(xplaneHost);
this.xplanePort = xplanePort;
this.inSocket.setSoTimeout(timeout);
}
/**
* Closes the underlying inSocket.
*/
public void close()
{
if(inSocket != null)
{
inSocket.close();
inSocket = null;
}
if(outSocket != null)
{
outSocket.close();
outSocket = null;
}
}
/**
* Read data from the X-Plane plugin. This method will read whatever data is available and return it.
*
* @return The data send from X-Plane.
* @throws IOException If the read operation fails
*/
private byte[] readUDP() throws IOException //TODO: Store data in a class level buffer to account for partial messages
{
byte[] buffer = new byte[2048];
DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
try
{
inSocket.receive(packet);
return Arrays.copyOf(buffer, buffer[4]);
}
catch (SocketTimeoutException ex)
{
return new byte[0];
}
}
/**
* Send the given data to the X-Plane plugin. This method automatically sets the length byte before sending,
* overwriting any value previously stored in @{code buffer[4]}.
*
* @param buffer The data to send.
* @throws IOException If the send operation fails.
*/
private void sendUDP(byte[] buffer) throws IOException
{
if(buffer.length < 5 || buffer.length > 255)
{
throw new IllegalArgumentException("buffer must be between 5 and 255 bytes long.");
}
buffer[4] = (byte)buffer.length;
DatagramPacket packet = new DatagramPacket(buffer, buffer.length, xplaneAddr, xplanePort);
outSocket.send(packet);
}
/**
* Pauses or unpauses X-Plane.
*
* @param pause {@code true} to pause the simulator; {@code false} to un-pause.
* @throws IOException If the command cannot be sent.
*/
public void pauseSim(boolean pause) throws IOException
{
// S I M U LEN VAL
byte[] msg = {0x53, 0x49, 0x4D, 0x55, 0x00, 0x00};
msg[5] = (byte)(pause ? 0x01 : 0x00);
sendUDP(msg);
}
/**
* Requests a single dref value from X-Plane.
*
* @param dref The name of the dref requested.
* @return A byte array representing data dependent on the dref requested.
* @throws IOException If either the request or the response fails.
*/
public float[] requestDREF(String dref) throws IOException
{
return requestDREFs(new String[]{dref})[0];
}
/**
* Requests several dref values from X-Plane.
*
* @param drefs An array of dref names to request.
* @return A multidimensional array representing the data for each requested dref.
* @throws IOException If either the request or the response fails.
*/
public float[][] requestDREFs(String[] drefs) throws IOException
{
//Preconditions
if(drefs == null || drefs.length == 0)
{
throw new IllegalArgumentException("drefs must be a valid array with at least one dref.");
}
if(drefs.length > 255)
{
throw new IllegalArgumentException("Can not request more than 255 DREFs at once.");
}
//Convert drefs to bytes.
byte[][] drefBytes = new byte[drefs.length][];
for(int i = 0; i < drefs.length; ++i)
{
drefBytes[i] = drefs[i].getBytes(StandardCharsets.UTF_8);
if(drefBytes[i].length == 0)
{
throw new IllegalArgumentException("DREF " + i + " is an empty string!");
}
if(drefBytes[i].length > 255)
{
throw new IllegalArgumentException("DREF " + i + " is too long (must be less than 255 bytes in UTF-8). Are you sure this is a valid DREF?");
}
}
//Build and send message
ByteArrayOutputStream os = new ByteArrayOutputStream();
os.write("GETD".getBytes(StandardCharsets.UTF_8));
os.write(0xFF); //Placeholder for message length
os.write(drefs.length);
for(byte[] dref : drefBytes)
{
os.write(dref.length);
os.write(dref, 0, dref.length);
}
sendUDP(os.toByteArray());
//Read response
for(int i = 0; i < 40; ++i)
{
byte[] data = readUDP();
if(data.length == 0)
{
continue;
}
if(data.length < 6)
{
throw new Error("Response too short"); //TODO: Make custom error type
}
if(data[5] != drefs.length)
{
throw new Error("Unexpected response length"); //TODO: Make custom error type
}
float[][] result = new float[drefs.length][];
ByteBuffer bb = ByteBuffer.wrap(data);
bb.order(ByteOrder.LITTLE_ENDIAN);
int cur = 6;
for(int j = 0; j < result.length; ++j)
{
result[j] = new float[data[cur++]];
for(int k = 0; k < result[j].length; ++k) //TODO: There must be a better way to do this
{
result[j][k] = bb.getFloat(cur);
cur += 4;
}
}
return result;
}
throw new IOException("No response received.");
}
public void sendDREF(String dref, float value) throws IOException
{
sendDREF(dref, new float[] {value});
}
/**
* Sends a command to X-Plane that sets the given DREF.
*
* @param dref The name of the DREF to set.
* @param value An array of floating point values whose structure depends on the dref specified.
* @throws IOException If the command cannot be sent.
*/
public void sendDREF(String dref, float[] value) throws IOException
{
//Preconditions
if(dref == null)
{
throw new IllegalArgumentException("dref must be a valid string.");
}
if(value == null || value.length == 0)
{
throw new IllegalArgumentException("value must be non-null and should contain at least one value.");
}
//Convert drefs to bytes.
byte[] drefBytes = dref.getBytes(StandardCharsets.UTF_8);
if(drefBytes.length == 0)
{
throw new IllegalArgumentException("DREF is an empty string!");
}
if(drefBytes.length > 255)
{
throw new IllegalArgumentException("dref must be less than 255 bytes in UTF-8. Are you sure this is a valid dref?");
}
ByteBuffer bb = ByteBuffer.allocate(4 * value.length);
bb.order(ByteOrder.LITTLE_ENDIAN);
for(int i = 0; i < value.length; ++i)
{
bb.putFloat(i * 4, value[i]);
}
//Build and send message
ByteArrayOutputStream os = new ByteArrayOutputStream();
os.write("DREF".getBytes(StandardCharsets.UTF_8));
os.write(0xFF); //Placeholder for message length
os.write(drefBytes.length);
os.write(drefBytes, 0, drefBytes.length);
os.write(value.length);
os.write(bb.array());
sendUDP(os.toByteArray());
}
/**
* Sends command to X-Plane setting control surfaces on the player aircraft.
*
* @param ctrl <p>An array containing zero to six values representing control surface data as follows:</p>
* <ol>
* <li>Latitudinal Stick [-1,1]</li>
* <li>Longitudinal Stick [-1,1]</li>
* <li>Rudder Pedals [-1, 1]</li>
* <li>Throttle [-1, 1]</li>
* <li>Gear (0=up, 1=down)</li>
* <li>Flaps [0, 1]</li>
* </ol>
* <p>
* If @{code ctrl} is less than 6 elements long, The missing elements will not be changed. To
* change values in the middle of the array without affecting the preceding values, set the
* preceding values to -998.
* </p>
* @throws IOException If the command cannot be sent.
*/
public void sendCTRL(float[] ctrl) throws IOException
{
sendCTRL(ctrl, 0);
}
/**
* Sends command to X-Plane setting control surfaces on the specified aircraft.
*
* @param ctrl <p>An array containing zero to six values representing control surface data as follows:</p>
* <ol>
* <li>Latitudinal Stick [-1,1]</li>
* <li>Longitudinal Stick [-1,1]</li>
* <li>Rudder Pedals [-1, 1]</li>
* <li>Throttle [-1, 1]</li>
* <li>Gear (0=up, 1=down)</li>
* <li>Flaps [0, 1]</li>
* </ol>
* <p>
* If @{code ctrl} is less than 6 elements long, The missing elements will not be changed. To
* change values in the middle of the array without affecting the preceding values, set the
* preceding values to -998.
* </p>
* @param aircraft The aircraft to set. 0 for the player's aircraft.
* @throws IOException If the command cannot be sent.
*/
private void sendCTRL(float[] ctrl, int aircraft) throws IOException
{
//Preconditions
if(ctrl == null)
{
throw new IllegalArgumentException("ctrl must no be null.");
}
if(ctrl.length > 6)
{
throw new IllegalArgumentException("ctrl must have 6 or fewer elements.");
}
if(aircraft < 0)
{
throw new IllegalArgumentException("aircraft must be non-negative.");
}
if(aircraft != 0) //TODO: Implement support for non-player aircraft on plugin side.
{
throw new Error("Non-player aircraft not supported yet.");
}
//Pad command values and convert to bytes
int i;
int cur = 0;
ByteBuffer bb = ByteBuffer.allocate(22);
bb.order(ByteOrder.LITTLE_ENDIAN);
for(i = 0; i < ctrl.length; ++i)
{
if(i == 4)
{
bb.put(cur, (byte) ctrl[i]);
cur += 1;
}
else
{
bb.putFloat(cur, ctrl[i]);
cur += 4;
}
}
for(; i < 6; ++i)
{
if(i == 4)
{
bb.put(cur, (byte) 0);
cur += 1;
}
else
{
bb.putFloat(cur, -998);
cur += 4;
}
}
//Build and send message
ByteArrayOutputStream os = new ByteArrayOutputStream();
os.write("CTRL".getBytes(StandardCharsets.UTF_8));
os.write(0xFF); //Placeholder for message length
os.write(bb.array());
sendUDP(os.toByteArray());
}
/**
* Sets the position of the player aircraft.
*
* @param posi <p>An array containing position elements as follows:</p>
* <ol>
* <li>Latitiude (deg)</li>
* <li>Longitude (deg)</li>
* <li>Altitude (m above MSL)</li>
* <li>Roll (deg)</li>
* <li>Pitch (deg)</li>
* <li>True Heading (deg)</li>
* <li>Gear (0=up, 1=down)</li>
* </ol>
* <p>
* If @{code ctrl} is less than 6 elements long, The missing elements will not be changed. To
* change values in the middle of the array without affecting the preceding values, set the
* preceding values to -998.
* </p>
* @throws IOException If the command can not be sent.
*/
public void sendPOSI(float[] posi) throws IOException
{
sendPOSI(posi, 0);
}
/**
* Sets the position of the specified aircraft.
*
* @param posi <p>An array containing position elements as follows:</p>
* <ol>
* <li>Latitiude (deg)</li>
* <li>Longitude (deg)</li>
* <li>Altitude (m above MSL)</li>
* <li>Roll (deg)</li>
* <li>Pitch (deg)</li>
* <li>True Heading (deg)</li>
* <li>Gear (0=up, 1=down)</li>
* </ol>
* <p>
* If @{code ctrl} is less than 6 elements long, The missing elements will not be changed. To
* change values in the middle of the array without affecting the preceding values, set the
* preceding values to -998.
* </p>
* @param aircraft The aircraft to set. 0 for the player aircraft.
* @throws IOException If the command can not be sent.
*/
public void sendPOSI(float[] posi, int aircraft) throws IOException
{
//Preconditions
if(posi == null)
{
throw new IllegalArgumentException("posi must no be null.");
}
if(posi.length > 7)
{
throw new IllegalArgumentException("posi must have 7 or fewer elements.");
}
if(aircraft < 0 || aircraft > 255)
{
throw new IllegalArgumentException("aircraft must be between 0 and 255.");
}
//Pad command values and convert to bytes
int i;
ByteBuffer bb = ByteBuffer.allocate(28);
bb.order(ByteOrder.LITTLE_ENDIAN);
for(i = 0; i < posi.length; ++i)
{
bb.putFloat(i * 4, posi[i]);
}
for(; i < 7; ++i)
{
bb.putFloat(i * 4, -998);
}
//Build and send message
ByteArrayOutputStream os = new ByteArrayOutputStream();
os.write("POSI".getBytes(StandardCharsets.UTF_8));
os.write(0xFF); //Placeholder for message length
os.write(aircraft);
os.write(bb.array());
sendUDP(os.toByteArray());
}
public void sendDATA(float[][] data) throws IOException
{
//Preconditions
if(data == null || data.length == 0)
{
throw new IllegalArgumentException("data must be a non-null, non-empty array.");
}
//Convert data to bytes
ByteBuffer bb = ByteBuffer.allocate(4 * 9 * data.length);
bb.order(ByteOrder.LITTLE_ENDIAN);
for(int i = 0; i < data.length; ++i)
{
int rowStart = 9 * 4 * i;
float[] row = data[i];
if(row.length != 9)
{
throw new IllegalArgumentException("Rows must contain exactly 9 items. (Row " + i + ")");
}
bb.putInt(rowStart, (int) row[0]);
for(int j = 1; j < row.length; ++j)
{
bb.putFloat(rowStart + 4 * j, row[j]);
}
}
//Build and send message
ByteArrayOutputStream os = new ByteArrayOutputStream();
os.write("DATA".getBytes(StandardCharsets.UTF_8));
os.write(0xFF); //Placeholder for message length
os.write(bb.array());
sendUDP(os.toByteArray());
}
/**
* Sets the port on which the client will receive data from X-Plane.
*
* @param recvPort The new incoming port number.
* @throws IOException If the command cannnot be sent.
*/
public void setCONN(int recvPort) throws IOException
{
if(recvPort < 0 || recvPort >= 0xFFFF)
{
throw new IllegalArgumentException("Invalid port (must be non-negative and less than 65536).");
}
ByteArrayOutputStream os = new ByteArrayOutputStream();
os.write("CONN".getBytes(StandardCharsets.UTF_8));
os.write(0xFF); //Placeholder for message length
os.write((byte) recvPort);
os.write((byte) (recvPort >> 8));
sendUDP(os.toByteArray());
int soTimeout = inSocket.getSoTimeout();
inSocket.close();
inSocket = new DatagramSocket(recvPort);
inSocket.setSoTimeout(soTimeout);
}
}