Packageflash.net
Classpublic class Socket
InheritanceSocket Inheritance EventDispatcher Inheritance Object
ImplementsIDataInput, IDataOutput

The Socket class enables ActionScript code to make socket connections and to read and write raw binary data. It is similar to XMLSocket but does not dictate the format of the received or transmitted data.

The Socket class is useful for working with servers that use binary protocols.

When you use this class, consider the Flash Player security model:

However, in the Apollo runtime, content in the application security sandbox (content installed with the Apollo application) are not restricted by these security limitations.

For more information, see the following:

View the examples.



Public Properties
 PropertyDefined by
  bytesAvailable : uint
[read-only] The number of bytes of data available for reading in the input buffer.
Socket
  connected : Boolean
[read-only] Indicates whether this Socket object is currently connected.
Socket
 Inheritedconstructor : Object
A reference to the class object or constructor function for a given object instance.
Object
  endian : String
Indicates the byte order for the data; possible values are constants from the flash.utils.Endian class, Endian.BIG_ENDIAN or Endian.LITTLE_ENDIAN.
Socket
  objectEncoding : uint
Controls the version of AMF used when writing or reading an object.
Socket
 Inheritedprototype : Object
[static] A reference to the prototype object of a class or function object.
Object
Public Methods
 MethodDefined by
  
Socket(host:String = null, port:int = 0)
Creates a Socket object.
Socket
 Inherited
addEventListener(type:String, listener:Function, useCapture:Boolean = false, priority:int = 0, useWeakReference:Boolean = false):void
Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event.
EventDispatcher
  
close():void
Closes the socket.
Socket
  
connect(host:String, port:int):void
Connects the socket to the specified host and port.
Socket
 Inherited
Dispatches an event into the event flow.
EventDispatcher
  
flush():void
Flushes any accumulated data in the socket's output buffer.
Socket
 Inherited
Checks whether the EventDispatcher object has any listeners registered for a specific type of event.
EventDispatcher
  
Reads a Boolean value from the socket.
Socket
  
Reads a signed byte from the socket.
Socket
  
readBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void
Reads the number of data bytes specified by the length parameter from the socket.
Socket
  
Reads an IEEE 754 double-precision floating-point number from the socket.
Socket
  
Reads an IEEE 754 single-precision floating-point number from the socket.
Socket
  
Reads a signed 32-bit integer from the socket.
Socket
  
readMultiByte(length:uint, charSet:String):String
Reads a multibyte string from the byte stream, using the specified character set.
Socket
  
Reads an object from the socket, encoded in AMF serialized format.
Socket
  
Reads a signed 16-bit integer from the socket.
Socket
  
Reads an unsigned byte from the socket.
Socket
  
Reads an unsigned 32-bit integer from the socket.
Socket
  
Reads an unsigned 16-bit integer from the socket.
Socket
  
Reads a UTF-8 string from the socket.
Socket
  
Reads the number of UTF-8 data bytes specified by the length parameter from the socket, and returns a string.
Socket
 Inherited
removeEventListener(type:String, listener:Function, useCapture:Boolean = false):void
Removes a listener from the EventDispatcher object.
EventDispatcher
 Inherited
setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void
Sets the availability of a dynamic property for loop operations.
Object
 Inherited
Returns the string representation of the specified object.
Object
 Inherited
Returns the primitive value of the specified object.
Object
 Inherited
Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type.
EventDispatcher
  
writeBoolean(value:Boolean):void
Writes a Boolean value to the socket.
Socket
  
writeByte(value:int):void
Writes a byte to the socket.
Socket
  
writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void
Writes a sequence of bytes from the specified byte array.
Socket
  
writeDouble(value:Number):void
Writes an IEEE 754 double-precision floating-point number to the socket.
Socket
  
writeFloat(value:Number):void
Writes an IEEE 754 single-precision floating-point number to the socket.
Socket
  
writeInt(value:int):void
Writes a 32-bit signed integer to the socket.
Socket
  
writeMultiByte(value:String, charSet:String):void
Writes a multibyte string from the byte stream, using the specified character set.
Socket
  
writeObject(object:*):void
Write an object to the socket in AMF serialized format.
Socket
  
writeShort(value:int):void
Writes a 16-bit integer to the socket.
Socket
  
writeUnsignedInt(value:uint):void
Writes a 32-bit unsigned integer to the socket.
Socket
  
writeUTF(value:String):void
Writes the following data to the socket: a 16-bit unsigned integer, which indicates the length of the specified UTF-8 string in bytes, followed by the string itself.
Socket
  
writeUTFBytes(value:String):void
Writes a UTF-8 string to the socket.
Socket
Events
 EventSummaryDefined by
 Inherited Dispatched when Flash Player gains operating system focus and becomes active.EventDispatcher
   Dispatched when the server closes the socket connection.Socket
   Dispatched when a network connection has been established.Socket
 Inherited Dispatched when Flash Player loses operating system focus and is becoming inactive.EventDispatcher
   Dispatched when an input/output error occurs that causes a send or load operation to fail.Socket
   Dispatched if a call to Socket.connect() attempts to connect either to a server outside the caller's security sandbox or to a port lower than 1024.Socket
   Dispatched when a socket has received data.Socket
Property detail
bytesAvailableproperty
bytesAvailable:uint  [read-only]

The number of bytes of data available for reading in the input buffer.

Your code must access bytesAvailable to ensure that sufficient data is available before trying to read it with one of the read methods.

Implementation
    public function get bytesAvailable():uint
connectedproperty 
connected:Boolean  [read-only]

Indicates whether this Socket object is currently connected. A call to this property returns a value of true if the socket is currently connected, or false otherwise.

Implementation
    public function get connected():Boolean
endianproperty 
endian:String  [read-write]

Indicates the byte order for the data; possible values are constants from the flash.utils.Endian class, Endian.BIG_ENDIAN or Endian.LITTLE_ENDIAN.

The default value is Endian.BIG_ENDIAN.

Implementation
    public function get endian():String
    public function set endian(value:String):void

See also

objectEncodingproperty 
objectEncoding:uint  [read-write]

Controls the version of AMF used when writing or reading an object.

Implementation
    public function get objectEncoding():uint
    public function set objectEncoding(value:uint):void

See also

Constructor detail
Socket()constructor
public function Socket(host:String = null, port:int = 0)

Creates a Socket object. If no parameters are specified, an initially disconnected socket is created. If parameters are specified, a connection is attempted to the specified host and port.

Parameters
host:String (default = null) — The name of the host to connect to. If this parameter is not specified, an initially disconnected socket is created.
 
port:int (default = 0) — The port number to connect to. If this parameter is not specified, an initially disconnected socket is created.

Events
connect:Event — Dispatched when a network connection has been established.
 
ioError:IOErrorEvent — Dispatched when an input/output error occurs that causes the connection to fail.
 
securityError:SecurityErrorEvent — Dispatched if a call to Socket.connect() attempts to connect either to a server outside the caller's security sandbox or to a port lower than 1024. You can work around either problem by using a cross-domain policy file on the server. For more information about policy files for sockets, see the "Flash Player Security" chapter in Programming ActionScript 3.0.

Throws
SecurityError — This error occurs for the following reasons:
  • Local untrusted SWF files cannot communicate with the Internet. You can work around this problem by reclassifying this SWF file as local-with-networking or trusted.
  • You cannot specify a socket port higher than 65535.
Method detail
close()method
public function close():void

Closes the socket. You cannot read or write any data after the close() method has been called.

The close event is dispatched only when the server closes the connection; it is not dispatched when you call the close() method.

You can reuse the Socket object by calling the connect() method on it again.


Throws
IOError — The socket could not be closed, or the socket was not open.
connect()method 
public function connect(host:String, port:int):void

Connects the socket to the specified host and port. If the connection fails immediately, either an event is dispatched or an exception is thrown: an error event is dispatched if a host was specified, and an exception is thrown if no host was specified. Otherwise, the status of the connection is reported by an event. If the socket is already connected, the existing connection is closed first.

By default, the value you pass for host must be in the same domain and the value you pass for port must be 1024 or higher. For example, a SWF file at adobe.com can connect only to a server daemon running at adobe.com. If you want to connect to a socket on a different host than the one from which the connecting SWF file was served, or if you want to connect to a port lower than 1024 on any host, you must obtain an xmlsocket: policy file from the host to which you are connecting. For more information, see the "Flash Player Security" chapter in Programming ActionScript 3.0.

Parameters
host:String — The name of the host to connect to. If no host is specified, the host that is contacted is the host where the calling SWF file resides. If you do not specify a host, use an event listener to determine whether the connection was successful.
 
port:int — The port number to connect to.

Events
connect:Event — Dispatched when a network connection has been established.
 
ioError:IOErrorEvent — Dispatched if a host is specified and an input/output error occurs that causes the connection to fail.
 
securityError:SecurityErrorEvent — Dispatched if a call to Socket.connect() attempts to connect to either a server outside the caller's security sandbox or to a port lower than 1024. You can work around either problem by using a cross-domain policy file on the server. For more information, see the "Flash Player Security" chapter in Programming ActionScript 3.0.

Throws
IOError — No host was specified and the connection failed.
 
SecurityError — This error occurs for the following reasons:
  • Local untrusted SWF files may not communicate with the Internet. You can work around this by reclassifying this SWF file as local-with-networking or trusted.
  • You cannot specify a socket port higher than 65535.
  • In the HTML page that contains the SWF content, the allowNetworking parameter of the the object and embed tags is set to "none".
flush()method 
public function flush():void

Flushes any accumulated data in the socket's output buffer. Data written by the write methods is not immediately transmitted; it is queued until the flush() method is called.


Throws
IOError — An I/O error occurred on the socket, or the socket is not open.
readBoolean()method 
public function readBoolean():Boolean

Reads a Boolean value from the socket. After reading a single byte, the method returns true if the byte is nonzero, and false otherwise.

Returns
Boolean — A value of true if the byte read is nonzero, otherwise false.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readByte()method 
public function readByte():int

Reads a signed byte from the socket.

Returns
int — A value from -128 to 127.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readBytes()method 
public function readBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void

Reads the number of data bytes specified by the length parameter from the socket. The bytes are read into the specified byte array, starting at the position indicated by offset.

Parameters
bytes:ByteArray — The ByteArray object to read data into.
 
offset:uint (default = 0) — The offset at which data reading should begin in the byte array.
 
length:uint (default = 0) — The number of bytes to read. The default value of 0 causes all available data to be read.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readDouble()method 
public function readDouble():Number

Reads an IEEE 754 double-precision floating-point number from the socket.

Returns
Number

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readFloat()method 
public function readFloat():Number

Reads an IEEE 754 single-precision floating-point number from the socket.

Returns
Number

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readInt()method 
public function readInt():int

Reads a signed 32-bit integer from the socket.

Returns
int — A value from -2147483648 to 2147483647.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readMultiByte()method 
public function readMultiByte(length:uint, charSet:String):String

Reads a multibyte string from the byte stream, using the specified character set.

Parameters
length:uint — The number of bytes from the byte stream to read.
 
charSet:String — The string denoting the character set to use to interpret the bytes. Possible character set strings include "shift_jis", "CN-GB", and "iso-8859-1". For a complete list, see Supported Character Sets.

Returns
String — A UTF-8 encoded string.

Throws
EOFError — There is insufficient data available to read.
readObject()method 
public function readObject():*

Reads an object from the socket, encoded in AMF serialized format.

Returns
* — The deserialized object

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

readShort()method 
public function readShort():int

Reads a signed 16-bit integer from the socket.

Returns
int — A value from -32768 to 32767.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readUnsignedByte()method 
public function readUnsignedByte():uint

Reads an unsigned byte from the socket.

Returns
uint — A value from 0 to 255.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readUnsignedInt()method 
public function readUnsignedInt():uint

Reads an unsigned 32-bit integer from the socket.

Returns
uint — A value from 0 to 4294967295.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readUnsignedShort()method 
public function readUnsignedShort():uint

Reads an unsigned 16-bit integer from the socket.

Returns
uint — A value from 0 to 65535.

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readUTF()method 
public function readUTF():String

Reads a UTF-8 string from the socket. The string is assumed to be prefixed with an unsigned short integer that indicates the length in bytes.

Returns
String

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
readUTFBytes()method 
public function readUTFBytes(length:uint):String

Reads the number of UTF-8 data bytes specified by the length parameter from the socket, and returns a string.

Parameters
length:uint — The number of bytes to read.

Returns
String

Throws
EOFError — There is insufficient data available to read.
 
IOError — An I/O error occurred on the socket, or the socket is not open.
writeBoolean()method 
public function writeBoolean(value:Boolean):void

Writes a Boolean value to the socket. This method writes a single byte, with either a value of 1 (true) or 0 (false).

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:Boolean — The value to write to the socket: 1 (true) or 0 (false).

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeByte()method 
public function writeByte(value:int):void

Writes a byte to the socket.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:int — The value to write to the socket. The low 8 bits of the value are used; the high 24 bits are ignored.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeBytes()method 
public function writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void

Writes a sequence of bytes from the specified byte array. The write operation starts at the position specified by offset.

If you omit the length parameter the default length of 0 causes the method to write the entire buffer starting at offset.

If you also omit the offset parameter, the entire buffer is written.

If offset or length is out of range, they are adjusted to match the beginning and end of the bytes array.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
bytes:ByteArray — The ByteArray object to write data from.
 
offset:uint (default = 0) — The zero-based offset into the bytes ByteArray object at which data writing should begin.
 
length:uint (default = 0) — The number of bytes to write. The default value of 0 causes the entire buffer to be written, starting at the value specified by the offset parameter.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeDouble()method 
public function writeDouble(value:Number):void

Writes an IEEE 754 double-precision floating-point number to the socket.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:Number — The value to write to the socket.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeFloat()method 
public function writeFloat(value:Number):void

Writes an IEEE 754 single-precision floating-point number to the socket.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:Number — The value to write to the socket.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeInt()method 
public function writeInt(value:int):void

Writes a 32-bit signed integer to the socket.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:int — The value to write to the socket.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeMultiByte()method 
public function writeMultiByte(value:String, charSet:String):void

Writes a multibyte string from the byte stream, using the specified character set.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:String — The string value to be written.
 
charSet:String — The string denoting the character set to use to interpret the bytes. Possible character set strings include "shift_jis", "CN-GB", and "iso-8859-1". For a complete list, see Supported Character Sets.

See also

writeObject()method 
public function writeObject(object:*):void

Write an object to the socket in AMF serialized format.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
object:* — The object to be serialized.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeShort()method 
public function writeShort(value:int):void

Writes a 16-bit integer to the socket. The bytes written are as follows:

(v >> 8) & 0xff v & 0xff

The low 16 bits of the parameter are used; the high 16 bits are ignored.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:int — The value to write to the socket.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeUnsignedInt()method 
public function writeUnsignedInt(value:uint):void

Writes a 32-bit unsigned integer to the socket.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:uint — The value to write to the socket.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeUTF()method 
public function writeUTF(value:String):void

Writes the following data to the socket: a 16-bit unsigned integer, which indicates the length of the specified UTF-8 string in bytes, followed by the string itself.

Before writing the string, the method calculates the number of bytes needed to represent all characters of the string.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:String — The string to write to the socket.

Throws
RangeError — The length is larger than 65535.
 
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

writeUTFBytes()method 
public function writeUTFBytes(value:String):void

Writes a UTF-8 string to the socket.

Note: Data written by this method is not immediately transmitted; it is queued until the flush() method is called.

Parameters
value:String — The string to write to the socket.

Throws
IOError — An I/O error occurred on the socket, or the socket is not open.

See also

Event detail
closeevent 
Event object type: flash.events.Event
Event.type property = flash.events.Event.CLOSE

Dispatched when the server closes the socket connection. The close event is dispatched only when the server closes the connection; it is not dispatched when you call the Socket.close() method.

Defines the value of the type property of a close event object.

This event has the following properties:

PropertyValue
bubblesfalse
cancelablefalse; there is no default behavior to cancel.
currentTargetThe object that is actively processing the Event object with an event listener.
targetThe object whose connection has been closed.
connectevent  
Event object type: flash.events.Event
Event.type property = flash.events.Event.CONNECT

Dispatched when a network connection has been established.

Defines the value of the type property of a connect event object.

This event has the following properties:

PropertyValue
bubblesfalse
cancelablefalse; there is no default behavior to cancel.
currentTargetThe object that is actively processing the Event object with an event listener.
targetThe Socket or XMLSocket object that has established a network connection.
ioErrorevent  
Event object type: flash.events.IOErrorEvent
IOErrorEvent.type property = flash.events.IOErrorEvent.IO_ERROR

Dispatched when an input/output error occurs that causes a send or load operation to fail.

Defines the value of the type property of an ioError event object.

This event has the following properties:

PropertyValue
bubblesfalse
cancelablefalse; there is no default behavior to cancel.
currentTargetThe object that is actively processing the Event object with an event listener.
errorIDA reference number associated with the specific error.
targetThe network object experiencing the input/output error.
textText to be displayed as an error message.
securityErrorevent  
Event object type: flash.events.SecurityErrorEvent
SecurityErrorEvent.type property = flash.events.SecurityErrorEvent.SECURITY_ERROR

Dispatched if a call to Socket.connect() attempts to connect either to a server outside the caller's security sandbox or to a port lower than 1024.

The SecurityErrorEvent.SECURITY_ERROR constant defines the value of the type property of a securityError event object.

This event has the following properties:

PropertyValue
bubblesfalse
cancelablefalse; there is no default behavior to cancel.
currentTargetThe object that is actively processing the Event object with an event listener.
targetThe network object reporting the security error.
textText to be displayed as an error message.

See also

socketDataevent  
Event object type: flash.events.ProgressEvent
ProgressEvent.type property = flash.events.ProgressEvent.SOCKET_DATA

Dispatched when a socket has received data. Events of type socketData do not use the ProgressEvent.bytesTotal property.

Defines the value of the type property of a socketData event object.

This event has the following properties:

PropertyValue
bubblesfalse
cancelablefalse; there is no default behavior to cancel.
currentTargetThe object that is actively processing the Event.
bytesLoadedThe number of items or bytes loaded at the time the listener processes the event.
bytesTotal0; this property is not used by socketData event objects.
targetThe Socket object reporting progress.
Examples

The following example reads from and writes to a socket and outputs information transmitted during socket events. Highlights of the example follow:
  1. The constructor creates a CustomSocket instance named socket and passes the host name localhost and port 80 as arguments. Since CustomSocket extends Socket, a call to super() calls Socket's constructor with localhost as the host name and 80 as the port number.
  2. The example then calls the configureListeners() method, which adds listeners for Socket events.

Note: To run the example, you need a server running on the same domain where the SWF resides (in the example, localhost) and listening on port 80.


package {
    import flash.display.Sprite;

    public class SocketExample extends Sprite {

        public function SocketExample() {
            var socket:CustomSocket = new CustomSocket("localhost", 80);
        }
    }
}

import flash.errors.*;
import flash.events.*;
import flash.net.Socket;

class CustomSocket extends Socket {
    private var response:String;

    public function CustomSocket(host:String = null, port:uint = 0) {
        super(host, port);
        configureListeners();
    }

    private function configureListeners():void {
        addEventListener(Event.CLOSE, closeHandler);
        addEventListener(Event.CONNECT, connectHandler);
        addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
        addEventListener(SecurityErrorEvent.SECURITY_ERROR, securityErrorHandler);
        addEventListener(ProgressEvent.SOCKET_DATA, socketDataHandler);
    }

    private function writeln(str:String):void {
        str += "\n";
        try {
            writeUTFBytes(str);
        }
        catch(e:IOError) {
            trace(e);
        }
    }

    private function sendRequest():void {
        trace("sendRequest");
        response = "";
        writeln("GET /");
        flush();
    }

    private function readResponse():void {
        var str:String = readUTFBytes(bytesAvailable);
        response += str;
    }

    private function closeHandler(event:Event):void {
        trace("closeHandler: " + event);
        trace(response.toString());
    }

    private function connectHandler(event:Event):void {
        trace("connectHandler: " + event);
        sendRequest();
    }

    private function ioErrorHandler(event:IOErrorEvent):void {
        trace("ioErrorHandler: " + event);
    }

    private function securityErrorHandler(event:SecurityErrorEvent):void {
        trace("securityErrorHandler: " + event);
    }

    private function socketDataHandler(event:ProgressEvent):void {
        trace("socketDataHandler: " + event);
        readResponse();
    }
}




 

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