org.apache.struts2.components

Class Bean

java.lang.Object

org.apache.struts2.components.Component

org.apache.struts2.components.ContextBean

org.apache.struts2.components.Bean

public class Bean
extends ContextBean

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

• var - the stack's context name (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" var="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" var="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 call 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

Fields

Modifier and Type	Field and Description
protected Object	bean
protected static org.apache.logging.log4j.Logger	LOG
protected String	name
protected ObjectFactory	objectFactory
protected ReflectionProvider	reflectionProvider

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

var

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

actionMapper, COMPONENT_STACK, devMode, parameters, stack, standardAttributesMap, throwExceptionOnELFailure

Constructor Summary

Constructors

Constructor and Description
Bean(ValueStack stack)

Method Summary

Methods

Modifier and Type	Method and Description
void	addParameter(String key, Object value) Adds the given key and value to this component's own parameter.
boolean	end(Writer writer, String body) Callback for the end tag of this component.
void	setName(String name)
void	setObjectFactory(ObjectFactory objectFactory)
void	setReflectionProvider(ReflectionProvider prov)
boolean	start(Writer writer) Callback for the start tag of this component.

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

getVar, putInContext, setVar

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

addAllParameters, altSyntax, completeExpressionIfAltSyntax, copyParams, determineActionURL, determineNamespace, end, fieldError, findAncestor, findString, findString, findStringIfAltSyntax, findValue, findValue, findValue, getComponentStack, getParameters, getStack, getStandardAttributes, isValidTagAttribute, popComponentStack, setActionMapper, setDevMode, setThrowExceptionsOnELFailure, setUrlHelper, stripExpressionIfAltSyntax, 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 final org.apache.logging.log4j.Logger LOG

bean

protected Object bean

name

protected String name

objectFactory

protected ObjectFactory objectFactory

reflectionProvider

protected ReflectionProvider reflectionProvider

Constructor Detail

Bean

public Bean(ValueStack stack)

Method Detail

setObjectFactory

public void setObjectFactory(ObjectFactory objectFactory)

setReflectionProvider

public void setReflectionProvider(ReflectionProvider prov)

start

public boolean start(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(Writer writer,
          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(String key,
                Object value)

Description copied from class: Component

Adds the given key and value to this component's own parameter.
If the provided key is null nothing happens. 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 associated with the key.

setName

public void setName(String name)