org.apache.velocity.tools.view.tools
Class ParameterParser

java.lang.Object
  org.apache.velocity.tools.generic.ValueParser
      org.apache.velocity.tools.view.tools.ParameterParser

All Implemented Interfaces:

ViewTool

public class ParameterParser

extends ValueParser

implements ViewTool

Utility class for easy parsing of ServletRequest parameters.

 Template example(s):
   $params.foo                ->  bar
   $params.getNumber('baz')   ->  12.6
   $params.getInt('baz')      ->  12
   $params.getNumbers('foo')  ->  [12.6]

 Toolbox configuration:
 <tool>
   <key>params</key>
   <scope>request</scope>
   <class>org.apache.velocity.tools.view.tools.ParameterParser</class>
 </tool>
 

When used as a view tool, this should only be used in the request scope. This class is, however, quite useful in your application's controller, filter, or action code as well as in templates.

Version:

$Revision: 326942 $ $Date: 2005-10-20 09:47:19 -0700 (Thu, 20 Oct 2005) $

Author:

Nathan Bubna

Field Summary

private javax.servlet.ServletRequest

request

Fields inherited from class org.apache.velocity.tools.generic.ValueParser

Constructor Summary

ParameterParser()
Constructs a new instance

ParameterParser(javax.servlet.ServletRequest request)
Constructs a new instance using the specified request.

Method Summary

protected javax.servlet.ServletRequest	getRequest() Returns the current ServletRequest for this instance.
protected java.util.Map	getSource() Overrides ValueParser.getSource() to return the result of getRequest().getParameterMap() if Servlet 2.3 or above is being used.
java.lang.String	getString(java.lang.String key) Overrides ValueParser.getString(String key) to retrieve the String from the ServletRequest instead of an arbitrary Map.
java.lang.String[]	getStrings(java.lang.String key) Overrides ValueParser.getString(String key) to retrieve Strings from the ServletRequest instead of an arbitrary Map.
void	init(java.lang.Object obj) Initializes this instance.
protected void	setRequest(javax.servlet.ServletRequest request) Sets the current ServletRequest
protected void	setSource(java.util.Map source) Overrides ValueParser.setSource(Map source) to throw an UnsupportedOperationException, because this class uses a servlet request as its source, not a Map.

Methods inherited from class org.apache.velocity.tools.generic.ValueParser

exists, get, getBoolean, getBoolean, getBoolean, getBooleans, getDouble, getDoubles, getInt, getInts, getNumber, getNumber, getNumbers, getString, parseBoolean, parseNumber

Methods inherited from class java.lang.Object

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

Field Detail

request

private javax.servlet.ServletRequest request

Constructor Detail

ParameterParser

public ParameterParser()

Constructs a new instance

ParameterParser

public ParameterParser(javax.servlet.ServletRequest request)

Constructs a new instance using the specified request.

Parameters:

request - the ServletRequest to be parsed

Method Detail

init

public void init(java.lang.Object obj)

Initializes this instance.

Specified by:

init in interface ViewTool

Parameters:

obj - the current ViewContext or ServletRequest

Throws:

java.lang.IllegalArgumentException - if the param is not a ViewContext or ServletRequest

setRequest

protected void setRequest(javax.servlet.ServletRequest request)

Sets the current ServletRequest

Parameters:

request - the ServletRequest to be parsed

getRequest

protected javax.servlet.ServletRequest getRequest()

Returns the current ServletRequest for this instance.

Returns:

the current ServletRequest

Throws:

java.lang.UnsupportedOperationException - if the request is null

getString

public java.lang.String getString(java.lang.String key)

Overrides ValueParser.getString(String key) to retrieve the String from the ServletRequest instead of an arbitrary Map.

Overrides:

getString in class ValueParser

Parameters:

key - the parameter's key

Returns:

parameter matching the specified key or null if there is no matching parameter

getStrings

public java.lang.String[] getStrings(java.lang.String key)

Overrides ValueParser.getString(String key) to retrieve Strings from the ServletRequest instead of an arbitrary Map.

Overrides:

getStrings in class ValueParser

Parameters:

key - the key for the desired parameter

Returns:

an array of String objects containing all of the values the given request parameter has, or null if the parameter does not exist

setSource

protected void setSource(java.util.Map source)

Overrides ValueParser.setSource(Map source) to throw an UnsupportedOperationException, because this class uses a servlet request as its source, not a Map.

Overrides:

setSource in class ValueParser

getSource

protected java.util.Map getSource()

Overrides ValueParser.getSource() to return the result of getRequest().getParameterMap() if Servlet 2.3 or above is being used. Otherwise, this throws an UnsupportedOperationException, because the class uses a servlet request as its source, not a Map.

Overrides:

getSource in class ValueParser