Package 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:

  • Field Details

    • 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 Details

  • Method Details

    • 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)