Attributes for Struts logic tags

Attributes for Struts logic tags

This reference material describes the attributes for the Struts logic tag library. By default, each element name has a logic: prefix.

For more information about the Struts tags and tag attributes, refer to the Apache Struts specifications.
Each Struts tag has a number of attributes that you can set by using the Properties view of the tag. Use this table of attributes while working with the Properties view of the tag, to look up attributes for which you want additional detail. Some attributes have the same name but different usage in different elements. The attributes are listed in alphabetical order.

<logic:empty />

<logic:equal />

<logic:forward />

<logic:greaterEqual />

<logic:greaterThan />

<logic:iterate />

<logic:lessEqual />

<logic:lessThan />

<logic:match />

<logic:messageNotPresent />

<logic:messagePresent />

<logic:notEmpty />

<logic:notEqual />

<logic:notMatch />

<logic:notPresent />

<logic:present />

<logic:redirect />

Empty

Table 1. Empty tag attributes
Attribute Description
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.

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Equal

Table 2. Equal tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Forward

Table 3. Forward tag attributes
Attribute Description
name Specifies the logical name of the global ActionForward entry that identifies the destination, and forwarding approach, to be used.

Note: Forwarding to tiles definitions is not supported from this tag. You should forward to them from an action.

Note: This is a required attribute.

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Greater Equal

Table 4. Greater equal tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Greater Than

Table 5. Greater than tag attributes
Properties Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Iterate

Table 6. Iterate tag attributes
Attribute Description
collection Specifies a runtime expression that evaluates to a collection (conforming to particular requirements) to be iterated over.
id Specifies the name of a page scope JavaServer Pages (JSP) bean that will contain the current element of the collection on each iteration, if it is not null.

Note: This is a required attribute.
indexId Specifies the name of a page scope JSP bean that will contain the current index of the collection on each iteration.
length Specifies the maximum number of entries (from the underlying collection) to be iterated through on this page. This can be either an integer that directly expresses the desired value, or the name of a JSP bean (in any scope) of type
java.lang.Integer that defines the desired value. By default, the number of iterations performed is not limited.
name Specifies the name of the JSP bean that contains the collection to be iterated (if you omit
property), or the JSP bean whose property getter returns the collection to be iterated (if you specify
property).
offset Specifies the zero-relative index of the starting point from which entries from the underlying collection will be iterated. This can be either an integer that directly expresses the desired value or the name of a JSP bean (in any scope) of type
java.lang.Integer that defines the desired value. The default value is zero, which means that the collection will be iterated from the beginning.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
type Specifies the fully qualified Java™ class name of the element to be exposed through the JSP bean named from the
id attribute. By default, no type conversions are performed.

Note: The actual elements of the collection must be assignment-compatible with this class, or a request time
ClassCastException error will occur.

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Less Equal

Table 7. Less equal tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Less Than

Table 8. Less than tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Match

Table 9. Match tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
location If not specified, a match between the variable and the value may occur at any position within the variable string. If specified, the match must occur at the specified location (either start or end) of the variable string.
name Specifies the variable to be matched is the JSP bean specified by this attribute, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Message Not Present

Table 10. Message not present tag attributes
Attribute Description
message If set to
true, retrieves the request scope bean from the Globals.MESSAGE_KEY constant string and ignores any value assigned to the
name attribute. By default the tag retrieves from the Globals.ERROR_KEY constant string the request scope bean over which it will iterate.
name Specifies the parameter key to retrieve the message from request scope.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.

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Message Present

Table 11. Message present tag attributes
Attribute Description
message If set to
true, retrieves the request scope bean from the Globals.MESSAGE_KEY constant string and ignores any value assigned to the
name attribute. By default the tag retrieves from the Globals.ERROR_KEY constant string the request scope bean over which it will iterate.
name Specifies the parameter key to retrieve the message from request scope.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.

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Not Empty

Table 12. Not empty tag attributes
Attribute Description
name Checks for the existence of a JSP bean, in any scope, with the specified name. If you also specify
property,
name checks for a non-null property value for the specified property.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.

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Not Equal

Table 13. Not equal tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Not Match

Table 14. Not match tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
location If not specified, a match between the variable and the value may occur at any position within the variable string. If specified, the match must occur at the specified location (either start or end) of the variable string.
name Specifies the variable to be matched is the JSP bean specified by this attribute, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

Note: This is a required attribute.

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Not Present

Table 15. Not present tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Specifies a JSP bean as the variable to be compared, if you omit
property, or the value of the specified property of this bean, if you specify
property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
value Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared.

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Present

Table 16. Present tag attributes
Attribute Description
cookie Specifies the name of a cookie whose value is to be compared with the value of the
value attribute.
header Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name Checks for the existence of a JSP bean, in any scope, with the specified name. If you also specify
property,
name checks for a non-null property value for the specified property.
parameter Specifies the name of the URL request parameter whose value is to be compared with the value of the
value attribute.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
role Checks whether the currently authenticated user (if any) has been associated with any of the specified security roles. To specify multiple roles, separate the role names with commas.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
user Checks whether the currently authenticated user has the specified name.

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Redirect

Table 17. Redirect tag attributes
Attribute Description
action Logical name of a global Action that contains the actual content-relative URI of the destination of this transfer. This hyperlink may be dynamically modified by the inclusion of query parameters, as described in the tag description. You must specify exactly one of the action attribute, the forward attribute, the href attribute, or the page attribute.
anchor Specifies an optional anchor tag (xxx) to be added as #xxx to the generated hyperlink.
forward Specifies the logical name of a global
ActionForward class that contains the actual content-relative URI of the destination of this
redirect element. You can modify the URI modified dynamically by including query parameters, as described in the tag description. You must specify exactly one of the following attributes:
forward,
href,
linkName, or
page.
href Specifies the URL to which this element will transfer control. You can modify the URL dynamically by the including query parameters as described in the tag description. You must specify exactly one of the following attributes:
forward,
href,
linkName, or
page.
name Specifies the name of a JSP bean that contains a
Map class that represents the query parameters (if you omit
property), or a JSP bean whose property getter is called to return a Map (if you specify
property).
page Specifies the context-relative path (beginning with a / character) to which this hyperlink will transfer control if activated. You can modify the hyperlink dynamically by including query parameters as described in the tag description. You must specify exactly one of the following attributes:
forward,
href,
linkName, or
page.
paramId Specifies the name of the request parameter that will be added dynamically to the generated hyperlink. The corresponding value is defined by the
paramName and (optional)
paramProperty attributes and is optionally scoped by the
paramScope attribute.
paramName Specifies the name of a JSP bean that is a String containing the value for the request parameter named by
paramId (if you omit
paramProperty), or a JSP bean whose property getter is called to return a String (if you specify
paramProperty). The JSP bean is constrained to the bean scope specified by the
paramScope property, if it is specified.
paramProperty Specifies the name of a property of the bean specified by the
paramName attribute, whose return value must be a String containing the value of the request parameter (named by the
paramId attribute) that will be added dynamically to this hyperlink.
paramScope Specifies the scope within which to search for the bean specified by the
paramName attribute. By default, all scopes are searched.
property Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope Specifies the bean scope within which to search for the bean named by the
name property. The default is to use any scope.
transaction If set to
true, includes the current transaction control token in the generated URL for this element.
useLocalEncoding If set to true, LocalCharacterEncoding will be used, that is, the characterEncoding set to the HttpServletResponse, as prefered character encoding rather than UTF-8, when URLEncoding is done on parameters of the URL.

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Attribute	Description
name	Specifies a JSP bean as the variable to be compared, if you omit `property`, or the value of the specified property of this bean, if you specify `property`.
property	Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope	Specifies the bean scope within which to search for the bean named by the `name` property. The default is to use any scope.

Attribute	Description
cookie	Specifies the name of a cookie whose value is to be compared with the value of the `value` attribute.
header	Specifies the name of the header whose value is to be compared. The name match is performed in a case-insensitive manner.
name	Specifies a JSP bean as the variable to be compared, if you omit `property`, or the value of the specified property of this bean, if you specify `property`.
parameter	Specifies the name of the URL request parameter whose value is to be compared with the value of the `value` attribute.
property	Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope	Specifies the bean scope within which to search for the bean named by the `name` property. The default is to use any scope.
value	Specifies the constant value to which the variable, specified by other attributes of this tag, will be compared. Note: This is a required attribute.

Attribute	Description
collection	Specifies a runtime expression that evaluates to a collection (conforming to particular requirements) to be iterated over.
id	Specifies the name of a page scope JavaServer Pages (JSP) bean that will contain the current element of the collection on each iteration, if it is not null. Note: This is a required attribute.
indexId	Specifies the name of a page scope JSP bean that will contain the current index of the collection on each iteration.
length	Specifies the maximum number of entries (from the underlying collection) to be iterated through on this page. This can be either an integer that directly expresses the desired value, or the name of a JSP bean (in any scope) of type java.lang.Integer that defines the desired value. By default, the number of iterations performed is not limited.
name	Specifies the name of the JSP bean that contains the collection to be iterated (if you omit `property`), or the JSP bean whose property getter returns the collection to be iterated (if you specify `property`).
offset	Specifies the zero-relative index of the starting point from which entries from the underlying collection will be iterated. This can be either an integer that directly expresses the desired value or the name of a JSP bean (in any scope) of type java.lang.Integer that defines the desired value. The default value is zero, which means that the collection will be iterated from the beginning.
property	Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope	Specifies the bean scope within which to search for the bean named by the `name` property. The default is to use any scope.
type	Specifies the fully qualified Java™ class name of the element to be exposed through the JSP bean named from the `id` attribute. By default, no type conversions are performed. Note: The actual elements of the collection must be assignment-compatible with this class, or a request time `ClassCastException` error will occur.

Attribute	Description
message	If set to `true`, retrieves the request scope bean from the Globals.MESSAGE_KEY constant string and ignores any value assigned to the `name` attribute. By default the tag retrieves from the Globals.ERROR_KEY constant string the request scope bean over which it will iterate.
name	Specifies the parameter key to retrieve the message from request scope.
property	Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.

Attribute	Description
name	Checks for the existence of a JSP bean, in any scope, with the specified name. If you also specify `property`, `name` checks for a non-null property value for the specified property.
property	Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope	Specifies the bean scope within which to search for the bean named by the `name` property. The default is to use any scope.

Attribute	Description
action	Logical name of a global Action that contains the actual content-relative URI of the destination of this transfer. This hyperlink may be dynamically modified by the inclusion of query parameters, as described in the tag description. You must specify exactly one of the action attribute, the forward attribute, the href attribute, or the page attribute.
anchor	Specifies an optional anchor tag (xxx) to be added as #xxx to the generated hyperlink.
forward	Specifies the logical name of a global `ActionForward` class that contains the actual content-relative URI of the destination of this `redirect` element. You can modify the URI modified dynamically by including query parameters, as described in the tag description. You must specify exactly one of the following attributes: `forward`, `href`, `linkName`, or `page`.
href	Specifies the URL to which this element will transfer control. You can modify the URL dynamically by the including query parameters as described in the tag description. You must specify exactly one of the following attributes: `forward`, `href`, `linkName`, or `page`.
name	Specifies the name of a JSP bean that contains a Map class that represents the query parameters (if you omit `property`), or a JSP bean whose property getter is called to return a Map (if you specify `property`).
page	Specifies the context-relative path (beginning with a / character) to which this hyperlink will transfer control if activated. You can modify the hyperlink dynamically by including query parameters as described in the tag description. You must specify exactly one of the following attributes: `forward`, `href`, `linkName`, or `page`.
paramId	Specifies the name of the request parameter that will be added dynamically to the generated hyperlink. The corresponding value is defined by the `paramName` and (optional) `paramProperty` attributes and is optionally scoped by the `paramScope` attribute.
paramName	Specifies the name of a JSP bean that is a String containing the value for the request parameter named by `paramId` (if you omit `paramProperty`), or a JSP bean whose property getter is called to return a String (if you specify `paramProperty`). The JSP bean is constrained to the bean scope specified by the `paramScope` property, if it is specified.
paramProperty	Specifies the name of a property of the bean specified by the `paramName` attribute, whose return value must be a String containing the value of the request parameter (named by the `paramId` attribute) that will be added dynamically to this hyperlink.
paramScope	Specifies the scope within which to search for the bean specified by the `paramName` attribute. By default, all scopes are searched.
property	Specifies the name of the property (of the bean specified by the name attribute) whose value is to be compared. The property reference can be simple, nested, or indexed.
scope	Specifies the bean scope within which to search for the bean named by the `name` property. The default is to use any scope.
transaction	If set to `true`, includes the current transaction control token in the generated URL for this element.
useLocalEncoding	If set to true, LocalCharacterEncoding will be used, that is, the characterEncoding set to the HttpServletResponse, as prefered character encoding rather than UTF-8, when URLEncoding is done on parameters of the URL.