org.sf.charttaglibs.utils
Class TagUtils

java.lang.Object
  org.sf.charttaglibs.utils.TagUtils

public class TagUtils

extends java.lang.Object

Provides helper methods for JSP tags.

Field Summary

private static TagUtils	instance The Singleton instance.
private static Message	messages The message resources for this package.
private static java.util.Map	scopes Maps lowercase JSP scope names to their PageContext integer constant values.

Constructor Summary

protected

TagUtils() Constructor for TagUtils.

Method Summary

static TagUtils	getInstance() Returns the Singleton instance of TagUtils.
int	getScope(java.lang.String scopeName) Converts the scope name into its corresponding PageContext constant value.
java.lang.Object	lookup(javax.servlet.jsp.PageContext pageContext, java.lang.String name, java.lang.String scopeName) Locate and return the specified bean, from an optionally specified scope, in the specified page context.
java.lang.Object	lookup(javax.servlet.jsp.PageContext pageContext, java.lang.String name, java.lang.String property, java.lang.String scope) Locate and return the specified property of the specified bean, from an optionally specified scope, in the specified page context.
void	write(javax.servlet.jsp.PageContext pageContext, java.lang.String text) Write the specified text as the response to the writer associated with this page.
void	writePrevious(javax.servlet.jsp.PageContext pageContext, java.lang.String text) Write the specified text as the response to the writer associated with the body content for the tag within which we are currently nested.

Methods inherited from class java.lang.Object

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

Field Detail

instance

private static final TagUtils instance

The Singleton instance.

messages

private static final Message messages

The message resources for this package.

scopes

private static final java.util.Map scopes

Maps lowercase JSP scope names to their PageContext integer constant values.

Constructor Detail

TagUtils

protected TagUtils()

Constructor for TagUtils.

Method Detail

getInstance

public static TagUtils getInstance()

Returns the Singleton instance of TagUtils.

getScope

public int getScope(java.lang.String scopeName)
             throws javax.servlet.jsp.JspException

Converts the scope name into its corresponding PageContext constant value.

Parameters:

scopeName - Can be "page", "request", "session", or "application" in any case.

Returns:

The constant representing the scope (ie. PageContext.REQUEST_SCOPE).

Throws:

javax.servlet.jsp.JspException - if the scopeName is not a valid name.

lookup

public java.lang.Object lookup(javax.servlet.jsp.PageContext pageContext,
                               java.lang.String name,
                               java.lang.String scopeName)
                        throws javax.servlet.jsp.JspException

Locate and return the specified bean, from an optionally specified scope, in the specified page context. If no such bean is found, return null instead. If an exception is thrown, it will have already been saved via a call to saveException().

Parameters:

pageContext - Page context to be searched

name - Name of the bean to be retrieved

scopeName - Scope to be searched (page, request, session, application) or null to use findAttribute() instead

Returns:

JavaBean in the specified page context

Throws:

javax.servlet.jsp.JspException - if an invalid scope name is requested

lookup

public java.lang.Object lookup(javax.servlet.jsp.PageContext pageContext,
                               java.lang.String name,
                               java.lang.String property,
                               java.lang.String scope)
                        throws javax.servlet.jsp.JspException

Locate and return the specified property of the specified bean, from an optionally specified scope, in the specified page context. If an exception is thrown, it will have already been saved via a call to saveException().

Parameters:

pageContext - Page context to be searched

name - Name of the bean to be retrieved

property - Name of the property to be retrieved, or null to retrieve the bean itself

scope - Scope to be searched (page, request, session, application) or null to use findAttribute() instead

Returns:

property of specified JavaBean

Throws:

javax.servlet.jsp.JspException - if an invalid scope name is requested

javax.servlet.jsp.JspException - if the specified bean is not found

javax.servlet.jsp.JspException - if accessing this property causes an IllegalAccessException, IllegalArgumentException, InvocationTargetException, or NoSuchMethodException

write

public void write(javax.servlet.jsp.PageContext pageContext,
                  java.lang.String text)
           throws javax.servlet.jsp.JspException

Write the specified text as the response to the writer associated with this page. WARNING - If you are writing body content from the doAfterBody() method of a custom tag class that implements BodyTag, you should be calling writePrevious() instead.

Parameters:

pageContext - The PageContext object for this page

text - The text to be written

Throws:

javax.servlet.jsp.JspException - if an input/output error occurs (already saved)

writePrevious

public void writePrevious(javax.servlet.jsp.PageContext pageContext,
                          java.lang.String text)
                   throws javax.servlet.jsp.JspException

Write the specified text as the response to the writer associated with the body content for the tag within which we are currently nested.

Parameters:

pageContext - The PageContext object for this page

text - The text to be written

Throws:

javax.servlet.jsp.JspException - if an input/output error occurs (already saved)