org.apache.ajp
Class Ajp13Packet

java.lang.Object
  org.apache.ajp.Ajp13Packet

public class Ajp13Packet

extends java.lang.Object

A single packet for communication between the web server and the container. Designed to be reused many times with no creation of garbage. Understands the format of data types for these packets. Can be used (somewhat confusingly) for both incoming and outgoing packets.

Author:

Henri Gomez [hgomez@apache.org], Dan Milstein [danmil@shore.net], Keith Wannamaker [Keith@Wannamaker.org], Kevin Seguin, Costin Manolache

See Also:

Ajp14/Ajp13Packet

Field Summary

static int	AJP13_SW_HEADER
static int	AJP13_WS_HEADER
static java.lang.String	DEFAULT_CHAR_ENCODING

Constructor Summary

Ajp13Packet(byte[] b)
Create a new packet with given bytes

Ajp13Packet(int size)
Create a new packet with an internal buffer of given size.

Method Summary

MessageBytes	addHeader(MimeHeaders headers)
void	appendBool(boolean val)
void	appendByte(byte val)
void	appendBytes(byte[] b, int off, int numBytes) Copy a chunk of bytes into the packet, starting at the current write position.
void	appendInt(int val)
void	appendLongInt(int val)
void	appendString(java.lang.String str) Write a String out at the current write position.
void	appendXBytes(byte[] b, int off, int numBytes) Copy a chunk of bytes into the packet, starting at the current write position.
int	checkIn() Parse the packet header for a packet sent from the web server to the container.
void	dump(java.lang.String msg)
void	end() For a packet to be sent to the web server, finish the process of accumulating data and write the length of the data payload into the header.
boolean	getBool()
byte[]	getBuff() Get the internal buffer
byte	getByte()
int	getByteOff() Get offset into internal buffer.
int	getBytes(byte[] dest) Copy a chunk of bytes from the packet into an array and advance the read position past the chunk.
java.lang.String	getEncoding() Get the encoding used for byte[] <-> string conversions.
int	getInt() Read an integer from packet, and advance the read position past it.
int	getLen() Get length.
int	getLongInt() Read a 32 bits integer from packet, and advance the read position past it.
void	getMessageBytes(MessageBytes mb)
java.lang.String	getString() Read a String from the packet, and advance the read position past it.
int	getXBytes(byte[] dest, int length) Copy a chunk of bytes from the packet into an array and advance the read position past the chunk.
byte	peekByte()
int	peekInt() Read an integer from the packet, but don't advance the read position past it.
int	peekLongInt() Read a 32 bits integer from the packet, but don't advance the read position past it.
void	reset() Prepare this packet for accumulating a message from the container to the web server.
void	setByteOff(int c) Set offset into internal buffer.
void	setEncoding(java.lang.String encoding) Set the encoding to use for byte[] <-> string conversions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_CHAR_ENCODING

public static final java.lang.String DEFAULT_CHAR_ENCODING

See Also:

Constant Field Values

AJP13_WS_HEADER

public static final int AJP13_WS_HEADER

See Also:

Constant Field Values

AJP13_SW_HEADER

public static final int AJP13_SW_HEADER

See Also:

Constant Field Values

Constructor Detail

Ajp13Packet

public Ajp13Packet(int size)

Create a new packet with an internal buffer of given size.

Parameters:

size - packet size

Ajp13Packet

public Ajp13Packet(byte[] b)

Create a new packet with given bytes

Parameters:

b - this packet's bytes.

Method Detail

setEncoding

public void setEncoding(java.lang.String encoding)

Set the encoding to use for byte[] <-> string conversions.

Parameters:

encoding - the encoding to use.

getEncoding

public java.lang.String getEncoding()

Get the encoding used for byte[] <-> string conversions.

Returns:

the encoding used.

getBuff

public byte[] getBuff()

Get the internal buffer

Returns:

internal buffer

getLen

public int getLen()

Get length.

Returns:

length -- This actually means different things depending on whether the packet is read or write. For read, it's the length of the payload (excluding the header). For write, it's the length of the packet as a whole (counting the header). Oh, well.

getByteOff

public int getByteOff()

Get offset into internal buffer.

Returns:

offset

setByteOff

public void setByteOff(int c)

Set offset into internal buffer.

Parameters:

c - new offset

checkIn

public int checkIn()

Parse the packet header for a packet sent from the web server to the container. Set the read position to immediately after the header.

Returns:

The length of the packet payload, as encoded in the header, or -1 if the packet doesn't have a valid header.

reset

public void reset()

Prepare this packet for accumulating a message from the container to the web server. Set the write position to just after the header (but leave the length unwritten, because it is as yet unknown).

end

public void end()

For a packet to be sent to the web server, finish the process of accumulating data and write the length of the data payload into the header.

appendInt

public void appendInt(int val)

appendByte

public void appendByte(byte val)

appendBool

public void appendBool(boolean val)

appendString

public void appendString(java.lang.String str)
                  throws java.io.UnsupportedEncodingException

Write a String out at the current write position. Strings are encoded with the length in two bytes first, then the string, and then a terminating \0 (which is not included in the encoded length). The terminator is for the convenience of the C code, where it saves a round of copying. A null string is encoded as a string with length 0.

Throws:

java.io.UnsupportedEncodingException

appendBytes

public void appendBytes(byte[] b,
                        int off,
                        int numBytes)

Copy a chunk of bytes into the packet, starting at the current write position. The chunk of bytes is encoded with the length in two bytes first, then the data itself, and finally a terminating \0 (which is not included in the encoded length).

Parameters:

b - The array from which to copy bytes.

off - The offset into the array at which to start copying

appendLongInt

public void appendLongInt(int val)

appendXBytes

public void appendXBytes(byte[] b,
                         int off,
                         int numBytes)

Copy a chunk of bytes into the packet, starting at the current write position. The chunk of bytes IS NOT ENCODED with ANY length header.

Parameters:

b - The array from which to copy bytes.

off - The offset into the array at which to start copying

getInt

public int getInt()

Read an integer from packet, and advance the read position past it. Integers are encoded as two unsigned bytes with the high-order byte first, and, as far as I can tell, in little-endian order within each byte.

peekInt

public int peekInt()

Read an integer from the packet, but don't advance the read position past it.

getByte

public byte getByte()

peekByte

public byte peekByte()

getBool

public boolean getBool()

getMessageBytes

public void getMessageBytes(MessageBytes mb)

addHeader

public MessageBytes addHeader(MimeHeaders headers)

getString

public java.lang.String getString()
                           throws java.io.UnsupportedEncodingException

Read a String from the packet, and advance the read position past it. See appendString for details on string encoding.

Throws:

java.io.UnsupportedEncodingException

getBytes

public int getBytes(byte[] dest)

Copy a chunk of bytes from the packet into an array and advance the read position past the chunk. See appendBytes() for details on the encoding.

Returns:

The number of bytes copied.

getLongInt

public int getLongInt()

Read a 32 bits integer from packet, and advance the read position past it. Integers are encoded as four unsigned bytes with the high-order byte first, and, as far as I can tell, in little-endian order within each byte.

getXBytes

public int getXBytes(byte[] dest,
                     int length)

Copy a chunk of bytes from the packet into an array and advance the read position past the chunk. See appendXBytes() for details on the encoding.

Returns:

The number of bytes copied.

peekLongInt

public int peekLongInt()

Read a 32 bits integer from the packet, but don't advance the read position past it.

dump

public void dump(java.lang.String msg)