org.apache.struts2.components
Class Bean

java.lang.Object
  org.apache.struts2.components.Component
      org.apache.struts2.components.Bean

public class Bean
extends Component

Instantiates a class that conforms to the JavaBeans specification. This tag has a body which can contain a number of Param elements to set any mutator methods on that class.

If the id attribute is set on the BeanTag, it will place the instantiated bean into the stack's Context.

• id - the stack's context id (if supplied) that the created bean will be store under
• name* - the class name of the bean to be instantiated (must respect JavaBean specification)

Examples:

 
 <-- in freemarker form -->
 [@s.bean name="org.apache.struts2.example.counter.SimpleCounter" id="counter"]
   [s:param name="foo" value="BAR"/]
   The value of foo is : [s:property value="foo"/], when inside the bean tag.

 [/s:bean]

 <-- in jsp form -->
 <s:bean name="org.apache.struts2.example.counter.SimpleCounter" id="counter">
         <s:param name="foo" value="BAR" />
   The value of foot is : <s:property value="foo"/>, when inside the bean tag <br />
 </s:bean>
 
 

This example instantiates a bean called SimpleCounter and sets the foo property (setFoo('BAR')). The SimpleCounter object is then pushed onto the Valuestack, which means that we can called its accessor methods (getFoo()) with the Property tag and get their values.

In the above example, the id has been set to a value of counter. This means that the SimpleCounter class will be placed into the stack's context. You can access the SimpleCounter class using a Struts tag:

 <-- jsp form -->
 <s:property value="#counter" />

 <-- freemarker form -->
 [s:property value="#counter.foo"/]
 

In the property tag example, the # tells Ognl to search the context for the SimpleCounter class which has an id(key) of counter

See Also:

Param

Field Summary

protected java.lang.Object	bean
protected static org.apache.commons.logging.Log	log
protected java.lang.String	name

Fields inherited from class org.apache.struts2.components.Component

COMPONENT_STACK, id, parameters, stack

Constructor Summary

Bean(com.opensymphony.xwork2.util.OgnlValueStack stack)

Method Summary

void	addParameter(java.lang.String key, java.lang.Object value) Add's the given key and value to this components own parameter.
boolean	end(java.io.Writer writer, java.lang.String body) Callback for the end tag of this component.
void	setName(java.lang.String name) the class name of the bean to be instantiated (must respect JavaBean specification)
boolean	start(java.io.Writer writer) Callback for the start tag of this component.

Methods inherited from class org.apache.struts2.components.Component

addAllParameters, altSyntax, copyParams, determineActionURL, determineNamespace, end, fieldError, findAncestor, findString, findString, findValue, findValue, findValue, getComponentStack, getId, getParameters, getStack, popComponentStack, setId, toString, usesBody

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static org.apache.commons.logging.Log log

bean

protected java.lang.Object bean

name

protected java.lang.String name

Constructor Detail

Bean

public Bean(com.opensymphony.xwork2.util.OgnlValueStack stack)

Method Detail

start

public boolean start(java.io.Writer writer)

Description copied from class: Component

Callback for the start tag of this component. Should the body be evaluated?

Overrides:

start in class Component

Parameters:

writer - the output writer.

Returns:

true if the body should be evaluated

end

public boolean end(java.io.Writer writer,
                   java.lang.String body)

Description copied from class: Component

Callback for the end tag of this component. Should the body be evaluated again?

NOTE: will pop component stack.

Overrides:

end in class Component

Parameters:

writer - the output writer.

body - the rendered body.

Returns:

true if the body should be evaluated again

addParameter

public void addParameter(java.lang.String key,
                         java.lang.Object value)

Description copied from class: Component

Add's the given key and value to this components own parameter.

If the provided key is null nothing happends. If the provided value is null any existing parameter with the given key name is removed.

Overrides:

addParameter in class Component

Parameters:

key - the key of the new parameter to add.

value - the value assoicated with the key.

setName

public void setName(java.lang.String name)

the class name of the bean to be instantiated (must respect JavaBean specification)