HeaderLineReader (JWAT common 1.2.1 API)

java.lang.Object
- org.jwat.common.HeaderLineReader

```
public class HeaderLineReader
extends java.lang.Object
```
Advanced header/line reader which can be configured into difference modes. The reader can either read normal lines or header lines. Supported encodings are raw, US-ASCII, ISO-8859-1 and UTF-8. Furthermore header lines can employ linear white space (LWS), quoted text and encoded words. After calling the readLine method additional information is available from public fields on the reader.

Author:

nicl

Field Summary

Fields
Modifier and Type	Field and Description
`protected boolean`	`bCr` True if the previous character was a CR.
`boolean`	`bEncodedWords` Support encoded words.
`boolean`	`bEof` Boolean indicating whether or not EOF has been reached on stream.
`int`	`bfErrors` Bit field of errors encountered while attempting to read a line.
`boolean`	`bLWS` Support LWS.
`boolean`	`bNameValue` Parses a headerline if true and a normal line if false.
`boolean`	`bQuotedText` Support quoted text.
`protected boolean`	`bValidChar` Used by decode method to indicated valid or non valid character.
`protected ByteArrayOutputStreamWithUnread`	`bytesOut` Stream used to record the raw characters read by the parser.
`protected static int`	`CC_CONTROL` Control character characteristic.
`protected static int`	`CC_SEPARATOR_WS` Separator character characteristic.
`static byte[]`	`charCharacteristicsTab` Table of separator characters.
`static int`	`E_BIT_EOF` Bit denoting unexpected EOF.
`static int`	`E_BIT_INVALID_CHARSET` Bit denoting an invalid encoding.
`static int`	`E_BIT_INVALID_CONTROL_CHAR` Bit denoting an invalid control character.
`static int`	`E_BIT_INVALID_QUOTED_PAIR_CHAR` Bit denoting an invalid quoted pair character.
`static int`	`E_BIT_INVALID_SEPARATOR_CHAR` Bit denoting an invalid separator character.
`static int`	`E_BIT_INVALID_US_ASCII_CHAR` Bit denoting an invalid US-ASCII character.
`static int`	`E_BIT_INVALID_UTF8_ENCODING` Bit denoting an invalid UTF-8 encoded character.
`static int`	`E_BIT_MISPLACED_CR` Bit denoting a misplaced CR.
`static int`	`E_BIT_MISSING_CR` Bit denoting a missing CR.
`static int`	`E_BIT_MISSING_QUOTE` Bit denoting a missing quote character.
`static int`	`E_BIT_MISSING_QUOTED_PAIR_CHAR` Bit denoting a missing quoted pair character.
`static int`	`E_BIT_UNEXPECTED_CR` Bit denoting an unexpected CR.
`static int`	`ENC_ISO8859_1` ISO-8859-1 encoding identifier.
`static int`	`ENC_RAW` Raw encoding identifier.
`static int`	`ENC_US_ASCII` US-ASCII encoding identifier.
`static int`	`ENC_UTF8` UTF-8 encoding identifier.
`int`	`encoding` Identifier for the expected character encoding.
`int`	`eol` Identifier for the Expected end of line character sequence.
`static int`	`EOL_CRLF` CRLF end of line identifier.
`static int`	`EOL_LF` LF end of line identifier.
`protected java.lang.StringBuffer`	`lineSb` Reusable `StringBuffer` for lines.
`protected java.lang.StringBuffer`	`nvSb` Reusable `StringBuffer` for name/value strings.
`protected static int`	`S_LINE` Initial state for reading a normal line.
`protected static int`	`S_LWS` State for reading a LWS character sequence.
`protected static int`	`S_NAME` Initial state for reading a header line.
`protected static int`	`S_QUOTED_LWS` State for reading a quoted LWS character sequence.
`protected static int`	`S_QUOTED_PAIR` State for reading a quoted pair character.
`protected static int`	`S_QUOTED_TEXT` State for reading a quoted string.
`protected static int`	`S_VALUE` State for reading a header value.
`static java.lang.String`	`separatorsWs` rfc2616 separator characters.
`protected UTF8`	`utf8` Reusable UTF-8 validation object instance.

Constructor Summary

Constructors
Modifier Constructor and Description

protected HeaderLineReader()
Prohibit public construction.

Constructors
Modifier	Constructor and Description
`protected`	`HeaderLineReader()` Prohibit public construction.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`check_eol()` Check and report whether the line ended as expected.
`protected int`	`decode(int c, java.io.InputStream in)` Decode a character according to the expected encoding.
`static HeaderLineReader`	`getHeaderLineReader()` Returns a reader initialized to read header lines.
`static HeaderLineReader`	`getLineReader()` Returns a reader initialized to read normal lines.
`static HeaderLineReader`	`getReader()` Returns a reader with default configuration values.
`HeaderLine`	`readLine(java.io.PushbackInputStream in)` Reads a header/line according to the configuration.
`static void`	`report_error(int bfErrors, Diagnostics diagnostics)` Report bit field errors as diagnoses.
`static java.lang.String`	`trim(java.lang.StringBuffer sb)` Trims the whitespace characters found in the beginning and end of a string.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - S_LINE
```
protected static final int S_LINE
```
    Initial state for reading a normal line.
    
    See Also:
    
    Constant Field Values
  - S_NAME
```
protected static final int S_NAME
```
    Initial state for reading a header line.
    
    See Also:
    
    Constant Field Values
  - S_VALUE
```
protected static final int S_VALUE
```
    State for reading a header value.
    
    See Also:
    
    Constant Field Values
  - S_LWS
```
protected static final int S_LWS
```
    State for reading a LWS character sequence.
    
    See Also:
    
    Constant Field Values
  - S_QUOTED_TEXT
```
protected static final int S_QUOTED_TEXT
```
    State for reading a quoted string.
    
    See Also:
    
    Constant Field Values
  - S_QUOTED_PAIR
```
protected static final int S_QUOTED_PAIR
```
    State for reading a quoted pair character.
    
    See Also:
    
    Constant Field Values
  - S_QUOTED_LWS
```
protected static final int S_QUOTED_LWS
```
    State for reading a quoted LWS character sequence.
    
    See Also:
    
    Constant Field Values
  - CC_CONTROL
```
protected static final int CC_CONTROL
```
    Control character characteristic.
    
    See Also:
    
    Constant Field Values
  - CC_SEPARATOR_WS
```
protected static final int CC_SEPARATOR_WS
```
    Separator character characteristic.
    
    See Also:
    
    Constant Field Values
  - separatorsWs
```
public static final java.lang.String separatorsWs
```
    rfc2616 separator characters.
    
    See Also:
    
    Constant Field Values
  - charCharacteristicsTab
```
public static final byte[] charCharacteristicsTab
```
    Table of separator characters.
  - ENC_RAW
```
public static final int ENC_RAW
```
    Raw encoding identifier.
    
    See Also:
    
    Constant Field Values
  - ENC_US_ASCII
```
public static final int ENC_US_ASCII
```
    US-ASCII encoding identifier.
    
    See Also:
    
    Constant Field Values
  - ENC_ISO8859_1
```
public static final int ENC_ISO8859_1
```
    ISO-8859-1 encoding identifier.
    
    See Also:
    
    Constant Field Values
  - ENC_UTF8
```
public static final int ENC_UTF8
```
    UTF-8 encoding identifier.
    
    See Also:
    
    Constant Field Values
  - utf8
```
protected final UTF8 utf8
```
    Reusable UTF-8 validation object instance.
  - EOL_LF
```
public static final int EOL_LF
```
    LF end of line identifier.
    
    See Also:
    
    Constant Field Values
  - EOL_CRLF
```
public static final int EOL_CRLF
```
    CRLF end of line identifier.
    
    See Also:
    
    Constant Field Values
  - bNameValue
```
public boolean bNameValue
```
    Parses a headerline if true and a normal line if false.
  - encoding
```
public int encoding
```
    Identifier for the expected character encoding.
  - eol
```
public int eol
```
    Identifier for the Expected end of line character sequence.
  - bLWS
```
public boolean bLWS
```
    Support LWS.
  - bQuotedText
```
public boolean bQuotedText
```
    Support quoted text.
  - bEncodedWords
```
public boolean bEncodedWords
```
    Support encoded words.
  - lineSb
```
protected final java.lang.StringBuffer lineSb
```
    Reusable StringBuffer for lines.
  - nvSb
```
protected final java.lang.StringBuffer nvSb
```
    Reusable StringBuffer for name/value strings.
  - bytesOut
```
protected ByteArrayOutputStreamWithUnread bytesOut
```
    Stream used to record the raw characters read by the parser.
  - E_BIT_EOF
```
public static final int E_BIT_EOF
```
    Bit denoting unexpected EOF.
    
    See Also:
    
    Constant Field Values
  - E_BIT_MISPLACED_CR
```
public static final int E_BIT_MISPLACED_CR
```
    Bit denoting a misplaced CR.
    
    See Also:
    
    Constant Field Values
  - E_BIT_MISSING_CR
```
public static final int E_BIT_MISSING_CR
```
    Bit denoting a missing CR.
    
    See Also:
    
    Constant Field Values
  - E_BIT_UNEXPECTED_CR
```
public static final int E_BIT_UNEXPECTED_CR
```
    Bit denoting an unexpected CR.
    
    See Also:
    
    Constant Field Values
  - E_BIT_INVALID_UTF8_ENCODING
```
public static final int E_BIT_INVALID_UTF8_ENCODING
```
    Bit denoting an invalid UTF-8 encoded character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_INVALID_US_ASCII_CHAR
```
public static final int E_BIT_INVALID_US_ASCII_CHAR
```
    Bit denoting an invalid US-ASCII character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_INVALID_CONTROL_CHAR
```
public static final int E_BIT_INVALID_CONTROL_CHAR
```
    Bit denoting an invalid control character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_INVALID_SEPARATOR_CHAR
```
public static final int E_BIT_INVALID_SEPARATOR_CHAR
```
    Bit denoting an invalid separator character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_MISSING_QUOTE
```
public static final int E_BIT_MISSING_QUOTE
```
    Bit denoting a missing quote character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_MISSING_QUOTED_PAIR_CHAR
```
public static final int E_BIT_MISSING_QUOTED_PAIR_CHAR
```
    Bit denoting a missing quoted pair character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_INVALID_QUOTED_PAIR_CHAR
```
public static final int E_BIT_INVALID_QUOTED_PAIR_CHAR
```
    Bit denoting an invalid quoted pair character.
    
    See Also:
    
    Constant Field Values
  - E_BIT_INVALID_CHARSET
```
public static final int E_BIT_INVALID_CHARSET
```
    Bit denoting an invalid encoding.
    
    See Also:
    
    Constant Field Values
  - bCr
```
protected boolean bCr
```
    True if the previous character was a CR.
  - bValidChar
```
protected boolean bValidChar
```
    Used by decode method to indicated valid or non valid character.
  - bEof
```
public boolean bEof
```
    Boolean indicating whether or not EOF has been reached on stream.
  - bfErrors
```
public int bfErrors
```
    Bit field of errors encountered while attempting to read a line.
- Constructor Detail
  - HeaderLineReader
```
protected HeaderLineReader()
```
    Prohibit public construction.
- Method Detail
  - getReader
```
public static HeaderLineReader getReader()
```
    Returns a reader with default configuration values.
    
    Returns:
    
    a reader with default configuration values
  - getLineReader
```
public static HeaderLineReader getLineReader()
```
    Returns a reader initialized to read normal lines. Normal lines being lines with no LWS or key:value headers. The reader is configured to expect US-ASCII characters.
    
    Returns:
    
    a reader to read normal lines
  - getHeaderLineReader
```
public static HeaderLineReader getHeaderLineReader()
```
    Returns a reader initialized to read header lines. The reader is configured to expect ISO-8859-1 encoding, LWS, quoted text and encoded words. Besides reading key:value headers it will also read and return normal lines as defined in the method above.
    
    Returns:
    
    a reader to read header lines
  - readLine
```
public HeaderLine readLine(java.io.PushbackInputStream in)
                    throws java.io.IOException
```
    Reads a header/line according to the configuration. After calling the readLine method additional information is available from public fields on the reader.
    
    Parameters:
    
    in - InputStream with characters
    
    Returns:
    
    result wrapped in a HeaderLine object
    
    Throws:
    
    java.io.IOException - if an I/O error occurs in the underlying input stream
  - decode
```
protected int decode(int c,
                     java.io.InputStream in)
              throws java.io.IOException
```
    Decode a character according to the expected encoding.
    
    Parameters:
    
    c - first character of the possibly encoded character sequence
    
    in - InputStream with possible extra encoded characters.
    
    Returns:
    
    decoded character
    
    Throws:
    
    java.io.IOException - if an I/O error occurs in the underlying input stream
  - check_eol
```
protected void check_eol()
```
    Check and report whether the line ended as expected.
  - trim
```
public static java.lang.String trim(java.lang.StringBuffer sb)
```
    Trims the whitespace characters found in the beginning and end of a string. Differs from the String method in that it leaves control characters.
    
    Parameters:
    
    sb - StringBuffer to be trimmed
    
    Returns:
    
    trimmed string
  - report_error
```
public static void report_error(int bfErrors,
                                Diagnostics diagnostics)
```
    Report bit field errors as diagnoses.
    
    Parameters:
    
    bfErrors - bit field with indicated errors
    
    diagnostics - diagnostics object used to report diagnoses

Class HeaderLineReader

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

S_LINE

S_NAME

S_VALUE

S_LWS

S_QUOTED_TEXT

S_QUOTED_PAIR

S_QUOTED_LWS

CC_CONTROL

CC_SEPARATOR_WS

separatorsWs

charCharacteristicsTab

ENC_RAW

ENC_US_ASCII

ENC_ISO8859_1

ENC_UTF8

utf8

EOL_LF

EOL_CRLF

bNameValue

encoding

eol

bLWS

bQuotedText

bEncodedWords

lineSb

nvSb

bytesOut

E_BIT_EOF

E_BIT_MISPLACED_CR

E_BIT_MISSING_CR

E_BIT_UNEXPECTED_CR

E_BIT_INVALID_UTF8_ENCODING

E_BIT_INVALID_US_ASCII_CHAR

E_BIT_INVALID_CONTROL_CHAR

E_BIT_INVALID_SEPARATOR_CHAR

E_BIT_MISSING_QUOTE

E_BIT_MISSING_QUOTED_PAIR_CHAR

E_BIT_INVALID_QUOTED_PAIR_CHAR

E_BIT_INVALID_CHARSET

bCr

bValidChar

bEof

bfErrors

Constructor Detail

HeaderLineReader

Method Detail

getReader

getLineReader

getHeaderLineReader

readLine

decode

check_eol

trim

report_error