org.unix4j.line

Interface Line

All Superinterfaces:

CharSequence

All Known Implementing Classes:

SimpleLine, SingleCharSequenceLine

public interface Line
extends CharSequence

A line is a line string including the line ending character(s). The getContent() method returns the line without line ending characters; getLineEnding() returns the only the line ending.

Note that line ending characters are not necessarily line separator characters for the current operating system as defined by the "line.separator" system property. The concrete encoding of line endings depends on the source of the line, which could for instance be an existing Windows or Unix file.

It is illegal for the content part of a line to contain any character of the line ending part. A line source must ensure that this constraint is fulfilled. Algorithms and programs may return undefined results or behave unpredictably for lines not following this rule.

Field Summary

Fields

Modifier and Type	Field and Description
static char	CR The carriage return (CR) character '\r' used to encode line endings in WINDOWS together with LF.
static Line	EMPTY_LINE Line with empty content string and a default operating system dependent line ending as defined by LINE_ENDING.
static char	LF The line feed (LF) character '\n' used to encode line endings in UNIX.
static String	LINE_ENDING Operating system dependent line ending taken from the system property "line.separator".
static char	ZERO The zero character '\0' used to encode line endings for special purpose use, such as find --print0 | xargs --delimiter0.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj) Compares this line with obj and returns true if obj is a Line (any subclass) and both lines are identical.
String	getContent() Returns the contents making up this line, but without the line ending characters.
int	getContentLength() Returns the length of the content string returned by getContent(), which is zero for a line without content and positive otherwise.
String	getLineEnding() Returns the line ending characters, usually one or two characters such as "\n" or "\r\n".
int	getLineEndingLength() Returns the length of the line ending string returned by getLineEnding(), which is usually one or two and sometimes zero the last line in a file is not terminated with a new line character.
int	hashCode() The hash code for this line, based on the complete line with line ending.
String	toString() Returns this line including the line ending characters as a string.

Methods inherited from interface java.lang.CharSequence

charAt, length, subSequence

Field Detail

LINE_ENDING

static final String LINE_ENDING

Operating system dependent line ending taken from the system property "line.separator". This is usually "\n" on UNIX systems and "\r\n" on WINDOWS.

EMPTY_LINE

static final Line EMPTY_LINE

Line with empty content string and a default operating system dependent line ending as defined by LINE_ENDING.

LF

static final char LF

The line feed (LF) character '\n' used to encode line endings in UNIX.

See Also:

Constant Field Values

CR

static final char CR

The carriage return (CR) character '\r' used to encode line endings in WINDOWS together with LF.

See Also:

Constant Field Values

ZERO

static final char ZERO

The zero character '\0' used to encode line endings for special purpose use, such as find --print0 | xargs --delimiter0.

See Also:

Constant Field Values

Method Detail

getContent

String getContent()

Returns the contents making up this line, but without the line ending characters. Returns an empty string if the line consists only of line ending characters.

Returns:

the line contents without line ending characters; can be an empty string but never null

getContentLength

int getContentLength()

Returns the length of the content string returned by getContent(), which is zero for a line without content and positive otherwise.

Returns:

the non-negative length of the content string returned by getContent()

getLineEnding

String getLineEnding()

Returns the line ending characters, usually one or two characters such as "\n" or "\r\n". If the last line in a file is not terminated with a new line character, the returned string can have zero length.

The encoding of line endings depends on the source of this line object. It is a single line feed character (LF="\n") if the source is a Unix type file, and carriage return followed by line feed (CR+LF= "\r\n") for lines from a Windows file.

Returns:

the line ending characters, usually a one or two character string and sometimes empty for the last line

getLineEndingLength

int getLineEndingLength()

Returns the length of the line ending string returned by getLineEnding(), which is usually one or two and sometimes zero the last line in a file is not terminated with a new line character.

Returns:

the length of the line ending string, usually one or two and sometimes zero for the last line

toString

String toString()

Returns this line including the line ending characters as a string.

Specified by:

toString in interface CharSequence

Overrides:

toString in class Object

Returns:

the line with line ending

equals

boolean equals(Object obj)

Compares this line with obj and returns true if obj is a Line (any subclass) and both lines are identical. The line comparison considers both the content and the line ending.

Overrides:

equals in class Object

Parameters:

obj - the object to be compared with

Returns:

true if obj is a Line identical to this Line also considering the line ending when comparing the lines

hashCode

int hashCode()

The hash code for this line, based on the complete line with line ending.

Overrides:

hashCode in class Object

Returns:

the hash code based on content and line ending