Package freemarker.ext.beans

Class BeanModel

java.lang.Object
freemarker.ext.beans.BeanModel
All Implemented Interfaces:
WrapperTemplateModel, AdapterTemplateModel, TemplateHashModel, TemplateHashModelEx, TemplateModel, TemplateModelWithAPISupport
Direct Known Subclasses:
ArrayModel, BooleanModel, DateModel, EnumerationModel, IteratorModel, NumberModel, ResourceBundleModel, StringModel
public class BeanModel extends Object implements TemplateHashModelEx, AdapterTemplateModel, WrapperTemplateModel, TemplateModelWithAPISupport
A class that will wrap an arbitrary object into TemplateHashModel interface allowing calls to arbitrary property getters and invocation of accessible methods on the object from a template using the object.foo to access properties and object.bar(arg1, arg2) to invoke methods on it. You can also use the object.foo[index] syntax to access indexed properties. It uses Beans Introspector to dynamically discover the properties and methods.

  • Field Details

  • Constructor Details

    • BeanModel

      public BeanModel(Object object, BeansWrapper wrapper)
      Creates a new model that wraps the specified object. Note that there are specialized subclasses of this class for wrapping arrays, collections, enumeration, iterators, and maps. Note also that the superclass can be used to wrap String objects if only scalar functionality is needed. You can also choose to delegate the choice over which model class is used for wrapping to BeansWrapper.wrap(Object).
      Parameters:
      object - the object to wrap into a model.
      wrapper - the BeansWrapper associated with this model. Every model has to have an associated BeansWrapper instance. The model gains many attributes from its wrapper, including the caching behavior, method exposure level, method-over-item shadowing policy etc.

  • Method Details

    • get

      public TemplateModel get(String key) throws TemplateModelException
      Uses Beans introspection to locate a property or method with name matching the key name. If a method or property is found, it's wrapped into TemplateMethodModelEx (for a method or indexed property), or evaluated on-the-fly and the return value wrapped into appropriate model (for a non-indexed property). Models for various properties and methods are cached on a per-class basis, so the costly introspection is performed only once per property or method of a class. (Side-note: this also implies that any class whose method has been called will be strongly referred to by the framework and will not become unloadable until this class has been unloaded first. Normally this is not an issue, but can be in a rare scenario where you create many classes on- the-fly. Also, as the cache grows with new classes and methods introduced to the framework, it may appear as if it were leaking memory. The framework does, however detect class reloads (if you happen to be in an environment that does this kind of things--servlet containers do it when they reload a web application) and flushes the cache. If no method or property matching the key is found, the framework will try to invoke methods with signature non-void-return-type get(java.lang.String), then non-void-return-type get(java.lang.Object), or alternatively (if the wrapped object is a resource bundle) Object getObject(java.lang.String).
      Specified by:
      get in interface TemplateHashModel
      Parameters:
      key - the name by which the TemplateModel is identified in the template.
      Returns:
      the TemplateModel referred to by the key, or null if not found.
      Throws:
      TemplateModelException - if there was no property nor method nor a generic get method to invoke.

    • hasPlainGetMethod

      protected boolean hasPlainGetMethod()
      Whether the model has a plain get(String) or get(Object) method

    • invokeGenericGet

      protected TemplateModel invokeGenericGet(Map classInfo, Class<?> clazz, String key) throws IllegalAccessException, InvocationTargetException, TemplateModelException
      Throws:
      IllegalAccessException
      InvocationTargetException
      TemplateModelException

    • wrap

      protected TemplateModel wrap(Object obj) throws TemplateModelException
      Throws:
      TemplateModelException

    • unwrap

      protected Object unwrap(TemplateModel model) throws TemplateModelException
      Throws:
      TemplateModelException

    • isEmpty

      public boolean isEmpty()
      Tells whether the model is empty. It is empty if either the wrapped object is null, or it's a Boolean with false value.
      Specified by:
      isEmpty in interface TemplateHashModel

    • getAdaptedObject

      public Object getAdaptedObject(Class<?> hint)
      Returns the same as getWrappedObject(); to ensure that, this method will be final starting from 2.4. This behavior of BeanModel is assumed by some FreeMarker code.
      Specified by:
      getAdaptedObject in interface AdapterTemplateModel
      Parameters:
      hint - the desired class of the returned value. An implementation should make reasonable effort to retrieve an object of the requested class, but if that is impossible, it must at least return the underlying object as-is. As a minimal requirement, an implementation must always return the exact underlying object when hint.isInstance(underlyingObject) holds. When called with java.lang.Object.class, it should return a generic Java object (i.e. if the model is wrapping a scripting language object that is further wrapping a Java object, the deepest underlying Java object should be returned).
      Returns:
      the underlying object, or its value accommodated for the hint class.

    • getWrappedObject

      public Object getWrappedObject()
      Description copied from interface: WrapperTemplateModel
      Retrieves the original object wrapped by this model.
      Specified by:
      getWrappedObject in interface WrapperTemplateModel

    • size

      public int size()
      Specified by:
      size in interface TemplateHashModelEx
      Returns:
      the number of key/value mappings in the hash.

    • keys

      public TemplateCollectionModel keys()
      Specified by:
      keys in interface TemplateHashModelEx
      Returns:
      a collection containing the keys in the hash. Every element of the returned collection must implement the TemplateScalarModel (as the keys of hashes are always strings).

    • values

      public TemplateCollectionModel values() throws TemplateModelException
      Specified by:
      values in interface TemplateHashModelEx
      Returns:
      a collection containing the values in the hash. The elements of the returned collection can be any kind of TemplateModel-s.
      Throws:
      TemplateModelException

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • keySet

      protected Set keySet()
      Helper method to support TemplateHashModelEx. Returns the Set of Strings which are available via the TemplateHashModel interface. Subclasses that override invokeGenericGet to provide additional hash keys should also override this method.

    • getAPI

      public TemplateModel getAPI() throws TemplateModelException
      Description copied from interface: TemplateModelWithAPISupport
      Returns the model that exposes the (Java) API of the value. This is usually implemented by delegating to ObjectWrapperWithAPISupport.wrapAsAPI(Object).
      Specified by:
      getAPI in interface TemplateModelWithAPISupport
      Throws:
      TemplateModelException