org.apache.tomcat.util.buf
Class ByteChunk

java.lang.Object
  extended byorg.apache.tomcat.util.buf.ByteChunk
All Implemented Interfaces:
java.lang.Cloneable, java.io.Serializable

public final class ByteChunk
extends java.lang.Object
implements java.lang.Cloneable, java.io.Serializable

This class is used to represent a chunk of bytes, and utilities to manipulate byte[]. The buffer can be modified and used for both input and output. There are 2 modes: The chunk can be associated with a sink - ByteInputChannel or ByteOutputChannel, which will be used when the buffer is empty ( on input ) or filled ( on output ). For output, it can also grow. This operating mode is selected by calling setLimit() or allocate(initial, limit) with limit != -1. Various search and append method are defined - similar with String and StringBuffer, but operating on bytes. This is important because it allows processing the http headers directly on the received bytes, without converting to chars and Strings until the strings are needed. In addition, the charset is determined later, from headers or user code.

Author:
dac@sun.com, James Todd [gonzo@sun.com], Costin Manolache, Remy Maucherat
See Also:
Serialized Form

Nested Class Summary
static interface ByteChunk.ByteInputChannel
          Input interface, used when the buffer is emptiy Same as java.nio.channel.ReadableByteChannel
static interface ByteChunk.ByteOutputChannel
          Same as java.nio.channel.WrittableByteChannel.
 
Field Summary
static java.nio.charset.Charset DEFAULT_CHARSET
          Default encoding used to convert to strings.
 
Constructor Summary
ByteChunk()
          Creates a new, uninitialized ByteChunk object.
ByteChunk(int initial)
           
 
Method Summary
 void allocate(int initial, int limit)
           
 void append(byte b)
           
 void append(byte[] src, int off, int len)
          Add data to the buffer
 void append(ByteChunk src)
           
 void append(char c)
          Append a char, by casting it to byte.
static byte[] convertToBytes(java.lang.String value)
          Convert specified String to a byte array.
 boolean equals(byte[] b2, int off2, int len2)
           
 boolean equals(ByteChunk bb)
           
 boolean equals(char[] c2, int off2, int len2)
           
 boolean equals(CharChunk cc)
           
 boolean equals(java.lang.String s)
          Compares the message bytes to the specified String object.
 boolean equalsIgnoreCase(java.lang.String s)
          Compares the message bytes to the specified String object.
static int findChar(byte[] buf, int start, int end, char c)
          Find a character, no side effects.
static int findChars(byte[] buf, int start, int end, byte[] c)
          Find a character, no side effects.
static int findNotChars(byte[] buf, int start, int end, byte[] c)
          Find the first character !
 void flushBuffer()
          Send the buffer to the sink.
 byte[] getBuffer()
          Returns the message bytes.
 byte[] getBytes()
          Returns the message bytes.
 java.nio.charset.Charset getCharset()
           
 ByteChunk getClone()
           
 int getEnd()
           
 int getInt()
           
 int getLength()
          Returns the length of the bytes.
 int getLimit()
           
 long getLong()
           
 int getOffset()
           
 int getStart()
          Returns the start offset of the bytes.
 int hash()
           
 int hashIgnoreCase()
           
static int indexOf(byte[] bytes, int off, int end, char qq)
           
 int indexOf(char c, int starting)
          Returns true if the message bytes starts with the specified string.
 int indexOf(java.lang.String src, int srcOff, int srcLen, int myOff)
           
 boolean isNull()
           
 void recycle()
          Resets the message buff to an uninitialized state.
 void reset()
           
 void setByteInputChannel(ByteChunk.ByteInputChannel in)
          When the buffer is empty, read the data from the input channel.
 void setByteOutputChannel(ByteChunk.ByteOutputChannel out)
          When the buffer is full, write the data to the output channel.
 void setBytes(byte[] b, int off, int len)
          Sets the message bytes to the specified subarray of bytes.
 void setCharset(java.nio.charset.Charset charset)
           
 void setEnd(int i)
           
 void setLimit(int limit)
          Maximum amount of data in this buffer.
 void setOffset(int off)
           
 void setOptimizedWrite(boolean optimizedWrite)
           
 boolean startsWith(byte[] b2)
           
 boolean startsWith(java.lang.String s)
          Returns true if the message bytes starts with the specified string.
 boolean startsWithIgnoreCase(java.lang.String s, int pos)
          Returns true if the message bytes starts with the specified string.
 int substract()
           
 int substract(byte[] src, int off, int len)
           
 int substract(ByteChunk src)
           
 java.lang.String toString()
           
 java.lang.String toStringInternal()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

DEFAULT_CHARSET

public static final java.nio.charset.Charset DEFAULT_CHARSET
Default encoding used to convert to strings. It should be UTF8, as most standards seem to converge, but the servlet API requires 8859_1, and this object is used mostly for servlets.

Constructor Detail

ByteChunk

public ByteChunk()
Creates a new, uninitialized ByteChunk object.


ByteChunk

public ByteChunk(int initial)
Method Detail

getClone

public ByteChunk getClone()

isNull

public boolean isNull()

recycle

public void recycle()
Resets the message buff to an uninitialized state.


reset

public void reset()

allocate

public void allocate(int initial,
                     int limit)

setBytes

public void setBytes(byte[] b,
                     int off,
                     int len)
Sets the message bytes to the specified subarray of bytes.

Parameters:
b - the ascii bytes
off - the start offset of the bytes
len - the length of the bytes

setOptimizedWrite

public void setOptimizedWrite(boolean optimizedWrite)

setCharset

public void setCharset(java.nio.charset.Charset charset)

getCharset

public java.nio.charset.Charset getCharset()

getBytes

public byte[] getBytes()
Returns the message bytes.


getBuffer

public byte[] getBuffer()
Returns the message bytes.


getStart

public int getStart()
Returns the start offset of the bytes. For output this is the end of the buffer.


getOffset

public int getOffset()

setOffset

public void setOffset(int off)

getLength

public int getLength()
Returns the length of the bytes. XXX need to clean this up


setLimit

public void setLimit(int limit)
Maximum amount of data in this buffer. If -1 or not set, the buffer will grow undefinitely. Can be smaller than the current buffer size ( which will not shrink ). When the limit is reached, the buffer will be flushed ( if out is set ) or throw exception.


getLimit

public int getLimit()

setByteInputChannel

public void setByteInputChannel(ByteChunk.ByteInputChannel in)
When the buffer is empty, read the data from the input channel.


setByteOutputChannel

public void setByteOutputChannel(ByteChunk.ByteOutputChannel out)
When the buffer is full, write the data to the output channel. Also used when large amount of data is appended. If not set, the buffer will grow to the limit.


getEnd

public int getEnd()

setEnd

public void setEnd(int i)

append

public void append(char c)
            throws java.io.IOException
Append a char, by casting it to byte. This IS NOT intended for unicode.

Parameters:
c -
Throws:
java.io.IOException

append

public void append(byte b)
            throws java.io.IOException
Throws:
java.io.IOException

append

public void append(ByteChunk src)
            throws java.io.IOException
Throws:
java.io.IOException

append

public void append(byte[] src,
                   int off,
                   int len)
            throws java.io.IOException
Add data to the buffer

Throws:
java.io.IOException

substract

public int substract()
              throws java.io.IOException
Throws:
java.io.IOException

substract

public int substract(ByteChunk src)
              throws java.io.IOException
Throws:
java.io.IOException

substract

public int substract(byte[] src,
                     int off,
                     int len)
              throws java.io.IOException
Throws:
java.io.IOException

flushBuffer

public void flushBuffer()
                 throws java.io.IOException
Send the buffer to the sink. Called by append() when the limit is reached. You can also call it explicitely to force the data to be written.

Throws:
java.io.IOException

toString

public java.lang.String toString()

toStringInternal

public java.lang.String toStringInternal()

getInt

public int getInt()

getLong

public long getLong()

equals

public boolean equals(java.lang.String s)
Compares the message bytes to the specified String object.

Parameters:
s - the String to compare
Returns:
true if the comparison succeeded, false otherwise

equalsIgnoreCase

public boolean equalsIgnoreCase(java.lang.String s)
Compares the message bytes to the specified String object.

Parameters:
s - the String to compare
Returns:
true if the comparison succeeded, false otherwise

equals

public boolean equals(ByteChunk bb)

equals

public boolean equals(byte[] b2,
                      int off2,
                      int len2)

equals

public boolean equals(CharChunk cc)

equals

public boolean equals(char[] c2,
                      int off2,
                      int len2)

startsWith

public boolean startsWith(java.lang.String s)
Returns true if the message bytes starts with the specified string.

Parameters:
s - the string

startsWith

public boolean startsWith(byte[] b2)

startsWithIgnoreCase

public boolean startsWithIgnoreCase(java.lang.String s,
                                    int pos)
Returns true if the message bytes starts with the specified string.

Parameters:
s - the string
pos - The position

indexOf

public int indexOf(java.lang.String src,
                   int srcOff,
                   int srcLen,
                   int myOff)

hash

public int hash()

hashIgnoreCase

public int hashIgnoreCase()

indexOf

public int indexOf(char c,
                   int starting)
Returns true if the message bytes starts with the specified string.

Parameters:
c - the character
starting - The start position

indexOf

public static int indexOf(byte[] bytes,
                          int off,
                          int end,
                          char qq)

findChar

public static int findChar(byte[] buf,
                           int start,
                           int end,
                           char c)
Find a character, no side effects.

Returns:
index of char if found, -1 if not

findChars

public static int findChars(byte[] buf,
                            int start,
                            int end,
                            byte[] c)
Find a character, no side effects.

Returns:
index of char if found, -1 if not

findNotChars

public static int findNotChars(byte[] buf,
                               int start,
                               int end,
                               byte[] c)
Find the first character != c

Returns:
index of char if found, -1 if not

convertToBytes

public static final byte[] convertToBytes(java.lang.String value)
Convert specified String to a byte array. This ONLY WORKS for ascii, UTF chars will be truncated.

Parameters:
value - to convert to byte array
Returns:
the byte array value


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