Language Version: | ActionScript 3.0 |
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.
To use the methods of the Socket class, first use the constructor,
new Socket
,
to create a Socket object.
SWF files in the local-with-filesystem sandbox may not use sockets.
Socket policy files
on the target host specify the hosts from which SWF files
can make socket connections, and the ports to which those connections can be made.
The security requirements with regard to socket policy files have become more stringent
in the last several releases of Flash Player.
In all versions of Flash Player, Adobe recommends the use of a socket policy file;
in some circumstances, a socket policy file is required. Therefore, if you
are using XMLSocket objects, make sure that the target host provides a socket policy file
if necessary.
The following list summarizes the requirements for socket policy files
in different versions of Flash Player:
- In Flash Player 9.0.124.0 and later, a socket policy file is required for any Socket connection.
That is, a socket policy file on the target host is required no matter what port
you are connecting to, and is required even if you are connecting
to a port on the same host that is serving the SWF file.
- In Flash Player versions 9.0.115.0 and earlier, if you want to connect to a port number below 1024,
or if you want to connect to a host other than the one serving the SWF file,
a socket policy file on the target host is required.
- In Flash Player 9.0.115.0, even if a socket policy file isn't required,
a warning is displayed when using the Flash Debug Player if the target host
doesn't serve a socket policy file.
For more information related to security, see the following:
-
The
security chapter
in the
Programming ActionScript 3.0
book and the latest comments on LiveDocs
-
The Flash Player Developer Center Topic:
Security
View the examples
bytesAvailable:uint
[read-only]
Language Version: | ActionScript 3.0 |
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
connected:Boolean
[read-only]
Language Version: | ActionScript 3.0 |
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
endian:String
[read-write]
Language Version: | ActionScript 3.0 |
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
objectEncoding:uint
[read-write]
Language Version: | ActionScript 3.0 |
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
timeout:uint
[read-write]
Language Version: | ActionScript 3.0 |
Runtime Versions: | 10, 1.5 |
Indicates the number of milliseconds to wait for a connection.
If the connection doesn't succeed within the specified time, the connection fails.
The default value is 20,000 (twenty seconds).
Implementation public function get timeout():uint
public function set timeout(value:uint):void
public function Socket(host:String = null, port:int = 0)
Language Version: | ActionScript 3.0 |
Creates a new 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.
Note:
It is strongly advised to use the constructor form
without parameters
, then
add any event listeners, then call the
connect
method with
host
and
port
parameters. This sequence guarantees that all event listeners will work
properly.
Parameters | host:String (default = null ) —
A fully qualified DNS domain name or an IP address in the form
111.222.333.444
. In Flash Player 9.0.115.0 and AIR 1.0 and later,
you can specify IPv6 addresses, such as rtmp://[2001:db8:ccc3:ffff:0:444d:555e:666f].
You can also specify
null
to connect to the host server
on which the SWF file resides. If the SWF file issuing this call is running in a web browser,
host
must be in the same domain as the SWF file.
|
|
| port:int (default = 0 ) — The TCP port number on the target host used to establish a connection.
In Flash Player 9.0.124.0 and later, the target host must serve a socket policy file
specifying that socket connections are permitted from the host serving the SWF file
to the specified port. In earlier versions of Flash Player, a socket policy file is required
only if you want to connect to a port number below 1024,
or if you want to connect to a host other than the one serving the SWF file. |
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 that doesn't serve a socket policy file,
or to a server whose policy file doesn't grant the calling host access to the specified port.
For more information about socket policy files, 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.
|
public function close():void
Language Version: | ActionScript 3.0 |
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. |
public function connect(host:String, port:int):void
Language Version: | ActionScript 3.0 |
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.
Parameters
| host:String — The name or IP address 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
either to a server that doesn't serve a socket policy file,
or to a server whose policy file doesn't grant the calling host access to the specified port.
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 limitation by reclassifying this
SWF file as local-with-networking or as trusted.
- You cannot specify a socket port higher than 65535.
-
In the HTML page that contains the SWF content, the
allowNetworking
parameter of the
object
and
embed
tags is set to
"none"
.
|
See also
public function flush():void
Language Version: | ActionScript 3.0 |
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. |
public function readBoolean():Boolean
Language Version: | ActionScript 3.0 |
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. |
public function readByte():int
Language Version: | ActionScript 3.0 |
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. |
public function readBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void
Language Version: | ActionScript 3.0 |
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. |
public function readDouble():Number
Language Version: | ActionScript 3.0 |
Reads an IEEE 754 double-precision floating-point number from the socket.
Returns | Number — An IEEE 754 double-precision floating-point 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. |
public function readFloat():Number
Language Version: | ActionScript 3.0 |
Reads an IEEE 754 single-precision floating-point number from the socket.
Returns | Number — An IEEE 754 single-precision floating-point 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. |
public function readInt():int
Language Version: | ActionScript 3.0 |
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. |
public function readMultiByte(length:uint, charSet:String):String
Language Version: | ActionScript 3.0 |
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
.
Note:
If the value for the
charSet
parameter is not recognized
by the current system, then Flash Player uses the system's default code page as the character set.
For example, a value for the
charSet
parameter, as in
myTest.readMultiByte(22, "iso-8859-01")
that uses
01
instead of
1
might work on your development machine, but not on another machine.
On the other machine, Flash Player will use the system's default code page.
|
Returns | String — A UTF-8 encoded string. |
Throws | EOFError — There is insufficient data available to read. |
public function readObject():*
Language Version: | ActionScript 3.0 |
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
public function readShort():int
Language Version: | ActionScript 3.0 |
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. |
public function readUnsignedByte():uint
Language Version: | ActionScript 3.0 |
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. |
public function readUnsignedInt():uint
Language Version: | ActionScript 3.0 |
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. |
public function readUnsignedShort():uint
Language Version: | ActionScript 3.0 |
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. |
public function readUTF():String
Language Version: | ActionScript 3.0 |
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.
ReturnsThrows | EOFError — There is insufficient data available to read. |
|
| IOError — An I/O error occurred on the socket, or the socket is not open. |
public function readUTFBytes(length:uint):String
Language Version: | ActionScript 3.0 |
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. |
ReturnsThrows | EOFError — There is insufficient data available to read. |
|
| IOError — An I/O error occurred on the socket, or the socket is not open. |
public function writeBoolean(value:Boolean):void
Language Version: | ActionScript 3.0 |
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
public function writeByte(value:int):void
Language Version: | ActionScript 3.0 |
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
public function writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void
Language Version: | ActionScript 3.0 |
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
public function writeDouble(value:Number):void
Language Version: | ActionScript 3.0 |
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
public function writeFloat(value:Number):void
Language Version: | ActionScript 3.0 |
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
public function writeInt(value:int):void
Language Version: | ActionScript 3.0 |
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
public function writeMultiByte(value:String, charSet:String):void
Language Version: | ActionScript 3.0 |
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
public function writeObject(object:*):void
Language Version: | ActionScript 3.0 |
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
public function writeShort(value:int):void
Language Version: | ActionScript 3.0 |
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
public function writeUnsignedInt(value:uint):void
Language Version: | ActionScript 3.0 |
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
public function writeUTF(value:String):void
Language Version: | ActionScript 3.0 |
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
that are 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
public function writeUTFBytes(value:String):void
Language Version: | ActionScript 3.0 |
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 Object Type: flash.events.Event
property Event.type = flash.events.Event.CLOSE
Language Version: | ActionScript 3.0 |
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:
Property | Value |
---|
bubbles
|
false
|
cancelable
|
false
; there is no default behavior to cancel.
|
currentTarget
| The object that is actively processing the Event
object with an event listener. |
target
| The object whose connection has been closed. |
Event Object Type: flash.events.Event
property Event.type = flash.events.Event.CONNECT
Language Version: | ActionScript 3.0 |
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:
Property | Value |
---|
bubbles
|
false
|
cancelable
|
false
; there is no default behavior to cancel.
|
currentTarget
| The object that is actively processing the Event
object with an event listener. |
target
| The Socket or XMLSocket object that has established a network connection. |
Event Object Type: flash.events.IOErrorEvent
property IOErrorEvent.type = flash.events.IOErrorEvent.IO_ERROR
Language Version: | ActionScript 3.0 |
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:
Property | Value |
---|
bubbles
|
false
|
cancelable
|
false
; there is no default behavior to cancel.
|
currentTarget
| The object that is actively processing the Event
object with an event listener. |
target
| The network object experiencing the input/output error. |
text
| Text to be displayed as an error message. |
Event Object Type: flash.events.SecurityErrorEvent
property SecurityErrorEvent.type = flash.events.SecurityErrorEvent.SECURITY_ERROR
Language Version: | ActionScript 3.0 |
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:
Property | Value |
---|
bubbles
|
false
|
cancelable
|
false
; there is no default behavior to cancel.
|
currentTarget
| The object that is actively processing the Event
object with an event listener. |
target
| The network object reporting the security error. |
text
| Text to be displayed as an error message. |
See also
Event Object Type: flash.events.ProgressEvent
property ProgressEvent.type = flash.events.ProgressEvent.SOCKET_DATA
Language Version: | ActionScript 3.0 |
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:
Property | Value |
---|
bubbles
|
false
|
cancelable
|
false
; there is no default behavior to cancel.
|
currentTarget
| The object that is actively processing the Event. |
bytesLoaded
| The number of items or bytes loaded at the time the listener processes the event. |
bytesTotal
|
0; this property is not used by
socketData
event objects.
|
target
| The Socket object reporting progress. |
The following example reads from and writes to a socket and outputs information
transmitted during socket events. Highlights of the example follow:
-
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.
-
The example then calls the
configureListeners()
method, which adds listeners for
Socket events.
-
Finally, the socket
connect()
method is called with
localhost
as the
host name and 80 as the port number.
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();
configureListeners();
if (host && port) {
super.connect(host, port);
}
}
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();
}
}
© 2004-2008 Adobe Systems Incorporated. All rights reserved.
Sun Oct 19 2008, 07:03 PM -07:00