com.opensymphony.xwork2.util
Class PropertiesReader

java.lang.Object
  extended by java.io.Reader
      extended by java.io.BufferedReader
          extended by java.io.LineNumberReader
              extended by 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. whether it starts with a comment character.
 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


Copyright © 2000-2008 Apache Software Foundation. All Rights Reserved.