Servoy 2020 Documentation
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Property Summary
Number index
Returns the current position in the byte array of the packet.

Method Summary
byte[] getByteArray()
Returns the content of the package into a byte array.
String getHost()
Returns the name of the host that sent the packet.
Number getLength()
Returns the length of the packet in bytes.
Number getPort()
Returns the port where the packet originated from.
Number readByte()
Reads an 8 bits byte value from the packet, starting from the current index.
Number readInt()
Reads a 32 bits int value from the packet, starting from the current index.
Number readShort()
Reads a 32 bits short value from the packet, starting from the current index.
String readUTF()
Reads a UTF-8 string from the packet, starting from the current index.
String readUTF(length)
Reads a UTF-8 string from the packet, starting from the current index.
void writeByte(number)
Writes one byte into the packet, at the current index.
void writeBytes(bytes)
Writes an array of bytes into the packet, at the current index.
void writeInt(number)
Writes a 32 bits int into the packet, at the current index.
void writeShort(number)
Writes a 16 bits short value into the packet, at the current index.
Number writeUTF(string)
Writes an UTF-8 encoded string into the packet, at the current index.

Property Details
index
Returns the current position in the byte array of the packet. The next read/write operation will occur at this position.
This is a 0 based index.
Returns
Number
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('an int is: ' + packet.readInt());
		application.output('moved to index: ' + packet.index);
		application.output('a short is: ' + packet.readShort());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
	}
	else {
		application.output('end of communication.');
		break;
	}
}

Method Details
getByteArray
byte[] getByteArray ()
Returns the content of the package into a byte array.
Returns
byte[]
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		var bytes = packet.getByteArray();
		application.output('received a packet of length: ' + bytes.length);
		for (var i=0; i<bytes.length; i++)
			application.output(bytes[i]);
		}
	else {
		application.output('end of communication.');
		break;
	}
}
getHost
String getHost ()
Returns the name of the host that sent the packet.
Returns
String
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('message is: ' + packet.readUTF());
	}
	else {
		application.output('end of communication.');
		break;
	}
}
getLength
Number getLength ()
Returns the length of the packet in bytes.
Returns
Number
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('message is: ' + packet.readUTF());
	}
	else {
		application.output('end of communication.');
		break;
	}
}
getPort
Number getPort ()
Returns the port where the packet originated from.
Returns
Number
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('message is: ' + packet.readUTF());
	}
	else {
		application.output('end of communication.');
		break;
	}
}
readByte
Number readByte ()
Reads an 8 bits byte value from the packet, starting from the current index. Advances the index with one position.
Returns
Number
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('an int is: ' + packet.readInt());
		application.output('moved to index: ' + packet.index);
		application.output('a short is: ' + packet.readShort());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
	}
	else {
		application.output('end of communication.');
		break;
	}
}
readInt
Number readInt ()
Reads a 32 bits int value from the packet, starting from the current index. Advances the index with 4 positions.
Returns
Number
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('an int is: ' + packet.readInt());
		application.output('moved to index: ' + packet.index);
		application.output('a short is: ' + packet.readShort());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
	}
	else {
		application.output('end of communication.');
		break;
	}
}
readShort
Number readShort ()
Reads a 32 bits short value from the packet, starting from the current index. Advances the index with 2 positions.
Returns
Number
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('an int is: ' + packet.readInt());
		application.output('moved to index: ' + packet.index);
		application.output('a short is: ' + packet.readShort());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
		application.output('a byte is: ' + packet.readByte());
		application.output('moved to index: ' + packet.index);
	}
	else {
		application.output('end of communication.');
		break;
	}
}
readUTF
String readUTF ()
Reads a UTF-8 string from the packet, starting from the current index. If an argument is specified, then it represents the length (in UTF-8 encoded bytes, not characters) of the string to read. If no argument is specified, then first a 32 bits (4 byte) int is read from the packet and that will be the byte length of the string. Advances the index with a number of positions that depends on the length of the read string.
Returns
String
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('message is: ' + packet.readUTF());
	}
	else {
		application.output('end of communication.');
		break;
	}
}
readUTF
String readUTF (length)
Reads a UTF-8 string from the packet, starting from the current index. If an argument is specified, then it represents the length (in UTF-8 encoded bytes, not characters) of the string to read. If no argument is specified, then first a 32 bits (4 byte) int is read from the packet and that will be the byte length of the string. Advances the index with a number of positions that depends on the length of the read string.
Parameters
{Number} length
Returns
String
Sample
var packet;
while (packet = plugins.udp.getReceivedPacket()) {
	application.output('packet received from ' + packet.getHost() + ':' + packet.getPort());
	if (packet.getLength() > 0) {
		application.output('message is: ' + packet.readUTF());
	}
	else {
		application.output('end of communication.');
		break;
	}
}
writeByte
void writeByte (number)
Writes one byte into the packet, at the current index. The index is advanced with one position.
Parameters
{Number} number
Returns
void
Sample
if (!plugins.udp.startSocket('5555', packetReceived)) {
	application.output('Failed to start socket.');
} else {
	var packet = plugins.udp.createNewPacket();
	packet.writeUTF('hello world!');
	plugins.udp.sendPacket('localhost', packet, 1234);
	packet = plugins.udp.createNewPacket();
	packet.writeByte(0xFF);
	packet.writeShort(10001);
	packet.writeInt(2000000001);
	plugins.udp.sendPacket('localhost', packet, 1234);
	var imgBytes = plugins.file.readFile('logo.jpg', 1024);
	packet = plugins.udp.createNewPacket();
	packet.writeBytes(imgBytes);
	plugins.udp.sendPacket('localhost', packet, 1234);
	plugins.udp.stopSocket();
}
writeBytes
void writeBytes (bytes)
Writes an array of bytes into the packet, at the current index. The index is advanced with a number of positions equal to the length of the written array.
Parameters
{byte[]} bytes
Returns
void
Sample
if (!plugins.udp.startSocket('5555', packetReceived)) {
	application.output('Failed to start socket.');
} else {
	var packet = plugins.udp.createNewPacket();
	packet.writeUTF('hello world!');
	plugins.udp.sendPacket('localhost', packet, 1234);
	packet = plugins.udp.createNewPacket();
	packet.writeByte(0xFF);
	packet.writeShort(10001);
	packet.writeInt(2000000001);
	plugins.udp.sendPacket('localhost', packet, 1234);
	var imgBytes = plugins.file.readFile('logo.jpg', 1024);
	packet = plugins.udp.createNewPacket();
	packet.writeBytes(imgBytes);
	plugins.udp.sendPacket('localhost', packet, 1234);
	plugins.udp.stopSocket();
}
writeInt
void writeInt (number)
Writes a 32 bits int into the packet, at the current index. The index is advances with 4 positions.
Parameters
{Number} number
Returns
void
Sample
if (!plugins.udp.startSocket('5555', packetReceived)) {
	application.output('Failed to start socket.');
} else {
	var packet = plugins.udp.createNewPacket();
	packet.writeUTF('hello world!');
	plugins.udp.sendPacket('localhost', packet, 1234);
	packet = plugins.udp.createNewPacket();
	packet.writeByte(0xFF);
	packet.writeShort(10001);
	packet.writeInt(2000000001);
	plugins.udp.sendPacket('localhost', packet, 1234);
	var imgBytes = plugins.file.readFile('logo.jpg', 1024);
	packet = plugins.udp.createNewPacket();
	packet.writeBytes(imgBytes);
	plugins.udp.sendPacket('localhost', packet, 1234);
	plugins.udp.stopSocket();
}
writeShort
void writeShort (number)
Writes a 16 bits short value into the packet, at the current index. The index is advances with 2 positions.
Parameters
{Number} number
Returns
void
Sample
if (!plugins.udp.startSocket('5555', packetReceived)) {
	application.output('Failed to start socket.');
} else {
	var packet = plugins.udp.createNewPacket();
	packet.writeUTF('hello world!');
	plugins.udp.sendPacket('localhost', packet, 1234);
	packet = plugins.udp.createNewPacket();
	packet.writeByte(0xFF);
	packet.writeShort(10001);
	packet.writeInt(2000000001);
	plugins.udp.sendPacket('localhost', packet, 1234);
	var imgBytes = plugins.file.readFile('logo.jpg', 1024);
	packet = plugins.udp.createNewPacket();
	packet.writeBytes(imgBytes);
	plugins.udp.sendPacket('localhost', packet, 1234);
	plugins.udp.stopSocket();
}
writeUTF
Number writeUTF (string)
Writes an UTF-8 encoded string into the packet, at the current index. First the length of the string is written on 4 bytes, then the string is written. The index is advanced with a number of positions equal to the length of the string plus 4.
Parameters
{String} string
Returns
Number
Sample
if (!plugins.udp.startSocket('5555', packetReceived)) {
	application.output('Failed to start socket.');
} else {
	var packet = plugins.udp.createNewPacket();
	packet.writeUTF('hello world!');
	plugins.udp.sendPacket('localhost', packet, 1234);
	packet = plugins.udp.createNewPacket();
	packet.writeByte(0xFF);
	packet.writeShort(10001);
	packet.writeInt(2000000001);
	plugins.udp.sendPacket('localhost', packet, 1234);
	var imgBytes = plugins.file.readFile('logo.jpg', 1024);
	packet = plugins.udp.createNewPacket();
	packet.writeBytes(imgBytes);
	plugins.udp.sendPacket('localhost', packet, 1234);
	plugins.udp.stopSocket();
}

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