org.apache.struts.tiles.taglib.util

Class TagUtils

java.lang.Object

org.apache.struts.tiles.taglib.util.TagUtils

public class TagUtils
extends java.lang.Object

Collection of utilities. This class also serves as an interface between Components and Struts. If you want to rip away Struts, simply reimplement some methods in this class. You can copy them from Struts.

Field Summary

Fields

Modifier and Type	Field and Description
static boolean	debug Debug flag

Constructor Summary

Constructors

Constructor and Description
TagUtils()

Method Summary

Modifier and Type	Method and Description
static java.lang.Object	findAttribute(java.lang.String beanName, javax.servlet.jsp.PageContext pageContext) Search attribute in different contexts.
static java.lang.Object	getAttribute(java.lang.String beanName, int scope, javax.servlet.jsp.PageContext pageContext) Get object from requested context.
static ComponentDefinition	getComponentDefinition(java.lang.String name, javax.servlet.jsp.PageContext pageContext) Get component definition by its name.
static java.lang.Object	getRealValueFromBean(java.lang.String beanName, java.lang.String beanProperty, java.lang.String beanScope, javax.servlet.jsp.PageContext pageContext) Locate and return the specified property of the specified bean, from an optionally specified scope, in the specified page context.
static int	getScope(java.lang.String scopeName) Converts the scope name into its corresponding PageContext constant value.
static int	getScope(java.lang.String scopeName, int defaultValue) Get scope value from string value
static java.lang.Object	retrieveBean(java.lang.String beanName, java.lang.String scopeName, javax.servlet.jsp.PageContext pageContext) Retrieve bean from page context, using specified scope.
static void	saveException(javax.servlet.jsp.PageContext pageContext, java.lang.Throwable exception) Save the specified exception as a request attribute for later use.
static void	setAttribute(javax.servlet.jsp.PageContext pageContext, java.lang.String name, java.lang.Object beanValue) Store bean in REQUEST_SCOPE context.
static void	setAttribute(javax.servlet.jsp.PageContext pageContext, java.lang.String name, java.lang.Object value, java.lang.String scope) Store bean in requested context.

Methods inherited from class java.lang.Object

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

Field Detail

debug

public static final boolean debug

Debug flag

See Also:

Constant Field Values

Constructor Detail

TagUtils

public TagUtils()

Method Detail

getScope

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

Get scope value from string value

Parameters:

scopeName - Scope as a String.

defaultValue - Returned default value, if not found.

Returns:

Scope as an int, or defaultValue if scope is null.

Throws:

javax.servlet.jsp.JspException - Scope name is not recognized as a valid scope.

getScope

public static 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.

retrieveBean

public static java.lang.Object retrieveBean(java.lang.String beanName,
                                            java.lang.String scopeName,
                                            javax.servlet.jsp.PageContext pageContext)
                                     throws javax.servlet.jsp.JspException

Retrieve bean from page context, using specified scope. If scope is not set, use findAttribute().

Parameters:

beanName - Name of bean to retrieve.

scopeName - Scope or null. If null, bean is searched using findAttribute().

pageContext - Current pageContext.

Returns:

Requested bean or null if not found.

Throws:

javax.servlet.jsp.JspException - Scope name is not recognized as a valid scope.

findAttribute

public static java.lang.Object findAttribute(java.lang.String beanName,
                                             javax.servlet.jsp.PageContext pageContext)

Search attribute in different contexts. First, check in component context, then use pageContext.findAttribute().

Parameters:

beanName - Name of bean to retrieve.

pageContext - Current pageContext.

Returns:

Requested bean or null if not found.

getAttribute

public static java.lang.Object getAttribute(java.lang.String beanName,
                                            int scope,
                                            javax.servlet.jsp.PageContext pageContext)

Get object from requested context. Return null if not found. Context can be "component" or normal JSP contexts.

Parameters:

beanName - Name of bean to retrieve.

scope - Scope from which bean must be retrieved.

pageContext - Current pageContext.

Returns:

Requested bean or null if not found.

getRealValueFromBean

public static java.lang.Object getRealValueFromBean(java.lang.String beanName,
                                                    java.lang.String beanProperty,
                                                    java.lang.String beanScope,
                                                    javax.servlet.jsp.PageContext pageContext)
                                             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.

Parameters:

pageContext - Page context to be searched.

beanName - Name of the bean to be retrieved.

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

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

Throws:

javax.servlet.jsp.JspException - Scope name is not recognized as a valid scope

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

setAttribute

public static void setAttribute(javax.servlet.jsp.PageContext pageContext,
                                java.lang.String name,
                                java.lang.Object value,
                                java.lang.String scope)
                         throws javax.servlet.jsp.JspException

Store bean in requested context. If scope is null, save it in REQUEST_SCOPE context.

Parameters:

pageContext - Current pageContext.

name - Name of the bean.

scope - Scope under which bean is saved (page, request, session, application) or null to store in request() instead.

value - Bean value to store.

Throws:

javax.servlet.jsp.JspException - Scope name is not recognized as a valid scope

setAttribute

public static void setAttribute(javax.servlet.jsp.PageContext pageContext,
                                java.lang.String name,
                                java.lang.Object beanValue)
                         throws javax.servlet.jsp.JspException

Store bean in REQUEST_SCOPE context.

Parameters:

pageContext - Current pageContext.

name - Name of the bean.

beanValue - Bean value to store.

Throws:

javax.servlet.jsp.JspException - Scope name is not recognized as a valid scope

saveException

public static void saveException(javax.servlet.jsp.PageContext pageContext,
                                 java.lang.Throwable exception)

Save the specified exception as a request attribute for later use.

Parameters:

pageContext - The PageContext for the current page.

exception - The exception to be saved.

getComponentDefinition

public static ComponentDefinition getComponentDefinition(java.lang.String name,
                                                         javax.servlet.jsp.PageContext pageContext)
                                                  throws javax.servlet.jsp.JspException

Get component definition by its name.

Parameters:

name - Definition name.

pageContext - The PageContext for the current page.

Throws:

javax.servlet.jsp.JspException - -