Package org.apache.coyote.ajp

Class AjpMessage

  • public class AjpMessage
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, Dan Milstein, Keith Wannamaker, Kevin Seguin, Costin Manolache

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected byte[] buf
      Fixed size buffer.
      protected int len
      This actually means different things depending on whether the packet is read or write.
      protected int pos
      The current read or write position in the buffer.
      protected static StringManager sm
      The string manager for this package.

    • Constructor Summary

      Constructors 
      Constructor Description
      AjpMessage​(int packetSize)  

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void appendByte​(int val)
      Append a byte (1 byte) to the message.
      void appendByteChunk​(ByteChunk bc)
      Write a ByteChunk out at the current write position.
      void appendBytes​(byte[] b, int off, int numBytes)
      Copy a chunk of bytes into the packet, starting at the current write position.
      void appendBytes​(java.nio.ByteBuffer b)
      Copy a chunk of bytes into the packet, starting at the current write position.
      void appendBytes​(MessageBytes mb)
      Write a MessageBytes out at the current write position.
      void appendInt​(int val)
      Add a short integer (2 bytes) to the message.
      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.
      void getBodyBytes​(MessageBytes mb)  
      byte[] getBuffer()
      Return the underlying byte buffer.
      byte getByte()  
      void getBytes​(MessageBytes mb)  
      int getInt()
      Read an integer from packet, and advance the read position past it.
      int getLen()
      Return the current message length.
      int getLongInt()
      Read a 32 bits integer from packet, and advance the read position past it.
      protected static java.lang.String hex​(int x)  
      protected static java.lang.String hexLine​(byte[] buf, int start, int len)  
      int peekInt()  
      int processHeader​(boolean toContainer)  
      void reset()
      Prepare this packet for accumulating a message from the container to the web server.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • sm

        protected static final StringManager sm
        The string manager for this package.

      • buf

        protected final byte[] buf
        Fixed size buffer.

      • pos

        protected int pos
        The current read or write position in the buffer.

      • len

        protected int len
        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.

    • Constructor Detail

      • AjpMessage

        public AjpMessage​(int packetSize)

    • Method Detail

      • 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.

      • getBuffer

        public byte[] getBuffer()
        Return the underlying byte buffer.
        Returns:
        The buffer

      • getLen

        public int getLen()
        Return the current message length.
        Returns:
        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).

      • appendInt

        public void appendInt​(int val)
        Add a short integer (2 bytes) to the message.
        Parameters:
        val - The integer to append

      • appendByte

        public void appendByte​(int val)
        Append a byte (1 byte) to the message.
        Parameters:
        val - The byte value to append

      • appendBytes

        public void appendBytes​(MessageBytes mb)
        Write a MessageBytes out at the current write position. A null MessageBytes is encoded as a string with length 0.
        Parameters:
        mb - The data to write

      • appendByteChunk

        public void appendByteChunk​(ByteChunk bc)
        Write a ByteChunk out at the current write position. A null ByteChunk is encoded as a string with length 0.
        Parameters:
        bc - The data to write

      • 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
        numBytes - The number of bytes to copy.

      • appendBytes

        public void appendBytes​(java.nio.ByteBuffer b)
        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 ByteBuffer from which to copy bytes.

      • 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.
        Returns:
        The integer value read from the message

      • peekInt

        public int peekInt()

      • getByte

        public byte getByte()

      • getBodyBytes

        public void getBodyBytes​(MessageBytes mb)

      • 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.
        Returns:
        The long value read from the message

      • processHeader

        public int processHeader​(boolean toContainer)

      • hexLine

        protected static java.lang.String hexLine​(byte[] buf,
                                          int start,
                                          int len)

      • hex

        protected static java.lang.String hex​(int x)