com.opensymphony.xwork2.util
Class PropertiesReader

java.lang.Object
  java.io.Reader
      java.io.BufferedReader
          java.io.LineNumberReader
              com.opensymphony.xwork2.util.PropertiesReader

All Implemented Interfaces:

Closeable, Readable

public class PropertiesReader
extends LineNumberReader

This class is used to read properties lines. These lines do not terminate with new-line chars but rather when there is no backslash sign a the end of the line. This is used to concatenate multiple lines for readability. This class was pulled out of Jakarta Commons Configuration and Jakarta Commons Lang trunk revision 476093

Field Summary

(package private) static String	COMMENT_CHARS Constant for the supported comment characters.
private List	commentLines Stores the comment lines for the currently processed property.
private char	delimiter Stores the list delimiter character.
private static int	HEX_RADIX Constant for the radix of hex numbers.
private String	propertyName Stores the name of the last read property.
private String	propertyValue Stores the value of the last read property.
private static char[]	SEPARATORS The list of possible key/value separators
private static int	UNICODE_LEN Constant for the length of a unicode literal.
private static char[]	WHITE_SPACE The white space characters used as key/value separators.

Fields inherited from class java.io.Reader

lock

Constructor Summary

PropertiesReader(Reader reader)
Constructor.

PropertiesReader(Reader reader, char listDelimiter)
Creates a new instance of PropertiesReader and sets the underlaying reader and the list delimiter.

Method Summary

private boolean	checkCombineLines(String line) Checks if the passed in line should be combined with the following.
boolean	contains(char[] array, char objectToFind) Checks if the object is in the given array.
List	getCommentLines() Returns the comment lines that have been read for the last property.
String	getPropertyName() Returns the name of the last read property.
String	getPropertyValue() Returns the value of the last read property.
(package private) boolean	isCommentLine(String line) Tests whether a line is a comment, i.e.
boolean	nextProperty() Parses the next property from the input stream and stores the found name and value in internal fields.
private String[]	parseProperty(String line) Parse a property line and return the key and the value in an array.
String	readProperty() Reads a property line.
static String	unescapeJava(String str) Unescapes any Java literals found in the String.
protected static String	unescapeJava(String str, char delimiter) Unescapes any Java literals found in the String to a Writer.
static void	unescapeJava(Writer out, String str) Unescapes any Java literals found in the String to a Writer.

Methods inherited from class java.io.LineNumberReader

getLineNumber, mark, read, read, readLine, reset, setLineNumber, skip

Methods inherited from class java.io.BufferedReader

close, markSupported, ready

Methods inherited from class java.io.Reader

read, read

Methods inherited from class java.lang.Object

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

Field Detail

commentLines

private List commentLines

Stores the comment lines for the currently processed property.

propertyName

private String propertyName

Stores the name of the last read property.

propertyValue

private String propertyValue

Stores the value of the last read property.

delimiter

private char delimiter

Stores the list delimiter character.

COMMENT_CHARS

static final String COMMENT_CHARS

Constant for the supported comment characters.

See Also:

Constant Field Values

HEX_RADIX

private static final int HEX_RADIX

Constant for the radix of hex numbers.

See Also:

Constant Field Values

UNICODE_LEN

private static final int UNICODE_LEN

Constant for the length of a unicode literal.

See Also:

Constant Field Values

SEPARATORS

private static final char[] SEPARATORS

The list of possible key/value separators

WHITE_SPACE

private static final char[] WHITE_SPACE

The white space characters used as key/value separators.

Constructor Detail

PropertiesReader

public PropertiesReader(Reader reader)

Constructor.

Parameters:

reader - A Reader.

PropertiesReader

public PropertiesReader(Reader reader,
                        char listDelimiter)

Creates a new instance of PropertiesReader and sets the underlaying reader and the list delimiter.

Parameters:

reader - the reader

listDelimiter - the list delimiter character

Since:

1.3

Method Detail

isCommentLine

boolean isCommentLine(String line)

Tests whether a line is a comment, i.e. whether it starts with a comment character.

Parameters:

line - the line

Returns:

a flag if this is a comment line

Since:

1.3

readProperty

public String readProperty()
                    throws IOException

Reads a property line. Returns null if Stream is at EOF. Concatenates lines ending with "\". Skips lines beginning with "#" or "!" and empty lines. The return value is a property definition (<name> = <value>)

Returns:

A string containing a property value or null

Throws:

IOException - in case of an I/O error

nextProperty

public boolean nextProperty()
                     throws IOException

Parses the next property from the input stream and stores the found name and value in internal fields. These fields can be obtained using the provided getter methods. The return value indicates whether EOF was reached (false) or whether further properties are available (true).

Returns:

a flag if further properties are available

Throws:

IOException - if an error occurs

Since:

1.3

getCommentLines

public List getCommentLines()

Returns the comment lines that have been read for the last property.

Returns:

the comment lines for the last property returned by readProperty()

Since:

1.3

getPropertyName

public String getPropertyName()

Returns the name of the last read property. This method can be called after nextProperty() was invoked and its return value was true.

Returns:

the name of the last read property

Since:

1.3

getPropertyValue

public String getPropertyValue()

Returns the value of the last read property. This method can be called after nextProperty() was invoked and its return value was true.

Returns:

the value of the last read property

Since:

1.3

checkCombineLines

private boolean checkCombineLines(String line)

Checks if the passed in line should be combined with the following. This is true, if the line ends with an odd number of backslashes.

Parameters:

line - the line

Returns:

a flag if the lines should be combined

parseProperty

private String[] parseProperty(String line)

Parse a property line and return the key and the value in an array.

Parameters:

line - the line to parse

Returns:

an array with the property's key and value

Since:

1.2

unescapeJava

protected static String unescapeJava(String str,
                                     char delimiter)

Unescapes any Java literals found in the String to a Writer.

This is a slightly modified version of the StringEscapeUtils.unescapeJava() function in commons-lang that doesn't drop escaped separators (i.e '\,').

Parameters:

str - the String to unescape, may be null

delimiter - the delimiter for multi-valued properties

Returns:

the processed string

Throws:

IllegalArgumentException - if the Writer is null

contains

public boolean contains(char[] array,
                        char objectToFind)

Checks if the object is in the given array.

The method returns false if a null array is passed in.

Parameters:

array - the array to search through

objectToFind - the object to find

Returns:

true if the array contains the object

unescapeJava

public static String unescapeJava(String str)

Unescapes any Java literals found in the String. For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.

Parameters:

str - the String to unescape, may be null

Returns:

a new unescaped String, null if null string input

unescapeJava

public static void unescapeJava(Writer out,
                                String str)
                         throws IOException

Unescapes any Java literals found in the String to a Writer.

For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.

A null string input has no effect.

Parameters:

out - the Writer used to output unescaped characters

str - the String to unescape, may be null

Throws:

IllegalArgumentException - if the Writer is null

IOException - if error occurs on underlying Writer