com.liferay.portal.kernel.util

Class StringParser

Object

com.liferay.portal.kernel.util.StringParser

public class StringParser
extends Object

Parses strings into parameter maps and vice versa.

Author:

Connor McKay, Brian Wing Shun Chan

See Also:

Route, Pattern

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	StringParser(String pattern) Constructs a new string parser from the pattern.

Method Summary

Modifier and Type	Method and Description
String	build(Map<String,String> parameters) Builds a string from the parameter map if this parser is appropriate.
static StringParser	create(String chunk)
static String	escapeRegex(String s) Escapes the special characters in the string so that they will have no special meaning in a regular expression.
boolean	parse(String s, Map<String,String> parameters) Populates the parameter map with values parsed from the string if this parser matches.
void	setStringEncoder(StringEncoder stringEncoder) Sets the string encoder to use for parsing or building a string.

Methods inherited from class Object

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

Constructor Detail

StringParser

protected StringParser(String pattern)

Constructs a new string parser from the pattern.

The pattern can be any string containing named fragments in brackets. The following is a valid pattern for greeting:

 
 Hi {name}! How are you?
 
 

This pattern would match the string "Hi Tom! How are you?". The format of a fragment may optionally be specified by inserting a colon followed by a regular expression after the fragment name. For instance, name could be set to match only lower case letters with the following:

 
 Hi {name:[a-z]+}! How are you?
 
 

By default, a fragment will match anything except a forward slash or a period.

If a string parser is set to encode fragments using a StringEncoder, an individual fragment can be specified as raw by prefixing its name with a percent sign, as shown below:

 
 /view_page/{%path:.*}
 
 

The format of the path fragment has also been specified to match anything using the pattern ".*". This pattern could be used to parse the string:

 
 /view_page/root/home/mysite/pages/index.htm
 
 

path would be set to "root/home/mysite/pages/index.htm", even if URLStringEncoder had been set as the string encoder.

Do not include capturing subgroups in the pattern.

Parameters:

pattern - the pattern string

Method Detail

create

public static StringParser create(String chunk)

escapeRegex

public static String escapeRegex(String s)

Escapes the special characters in the string so that they will have no special meaning in a regular expression.

This method differs from Pattern.quote(String) by escaping each special character with a backslash, rather than enclosing the entire string in special quote tags. This allows the escaped string to be manipulated or have sections replaced with non-literal sequences.

Parameters:

s - the string to escape

Returns:

the escaped string

build

public String build(Map<String,String> parameters)

Builds a string from the parameter map if this parser is appropriate.

A parser is appropriate if each parameter matches the format of its accompanying fragment.

If this parser is appropriate, all the parameters used in the pattern will be removed from the parameter map. If this parser is not appropriate, the parameter map will not be modified.

Parameters:

parameters - the parameter map to build the string from

Returns:

the string, or null if this parser is not appropriate

parse

public boolean parse(String s,
                     Map<String,String> parameters)

Populates the parameter map with values parsed from the string if this parser matches.

Parameters:

s - the string to parse

parameters - the parameter map to populate if this parser matches the string

Returns:

true if this parser matches; false otherwise

setStringEncoder

public void setStringEncoder(StringEncoder stringEncoder)

Sets the string encoder to use for parsing or building a string.

The string encoder will not be used for fragments marked as raw. A fragment can be marked as raw by prefixing its name with a percent sign.

Parameters:

stringEncoder - the string encoder to use for parsing or building a string

See Also:

StringEncoder