Class Beans

public Beans()

Once again, we have a java.beans class with only static methods that can be instantiated. When will the madness end? :)

public static Object getInstanceOf(Object bean,
                                   Class newClass)

Returns the Bean as a different class type. This should be used instead of casting to get a new type view of a Bean, because in the future there may be new types of Bean, even Beans spanning multiple Objects.

Parameters:

bean - the Bean to cast.

newClass - the Class to cast it to.

Returns:

the Bean as a new view, or if the operation could not be performed, the Bean itself.

public static Object instantiate(ClassLoader cl,
                                 String beanName)
            throws IOException,
                   ClassNotFoundException

Creates a bean.

This is a convenience method that calls instantiate(cl, beanName, null, null).

Parameters:

cl - ClassLoader to be used or null for the system classloader.

beanName - Name of a serialized bean or class name.

Returns:

A newly created bean.

Throws:

IOException - If access of an IO resource failed.

ClassNotFoundException - If the class name is not known or does not lead to a proper bean class.

See Also:

instantiate(ClassLoader, String, BeanContext, AppletInitializer)

public static Object instantiate(ClassLoader cl,
                                 String beanName,
                                 BeanContext beanContext)
            throws IOException,
                   ClassNotFoundException

Creates a bean.

This is a convenience method that calls instantiate(cl, beanName, beanContext, null).

Parameters:

cl - ClassLoader to be used or null for the system classloader.

beanName - Name of a serialized bean or class name.

beanContext - Context to which the newly created Bean should be added.

Returns:

A newly created bean.

Throws:

IOException - If access of an IO resource failed.

ClassNotFoundException - If the class name is not known or does not lead to a proper bean class.

See Also:

instantiate(ClassLoader, String, BeanContext, AppletInitializer)

public static Object instantiate(ClassLoader cl,
                                 String beanName,
                                 BeanContext beanContext,
                                 AppletInitializer initializer)
            throws IOException,
                   ClassNotFoundException

Instantiates a bean according to Beans 1.0.

In Beans 1.0 the instantiation scheme is as follows:

The name should be dot-separated (e.g "place.for.beans.myBean") and indicate either a serialized object or a class name. In the first case all dots in the name are replaced with slashes ('/') and ".ser" is appended ("place.for.beans.myBean" becomes "place/for/beans/myBean.ser"). The bean is then loaded as an application or system resource depending on whether a ClassLoader was provided.

If no such resource exists or if it contains no bean the name is interpreted as a class name of which an instance is then created.

If a BeanContext instance is available the created bean is added to it.

If the created Bean is an Applet or subclass and an AppletInitializer instance is available the applet is initialized and afterwards activated using the initializer. Additionally every instantiated Applet bean is initialized using the Applet.init method. Furthermore every applet gets a default AppletStub. The Applet's document base is the location of the ".ser" file if it was deserialized or the location of its class file if it was instantiated.

A ClassNotFoundException is not only thrown when a class name was unknown but even when the class has public no-argument constructor (IllegalAccessException is wrapped) or an exception is thrown while invoking such a constructor (causing exception is wrapped).

Parameters:

cl - ClassLoader to be used or null for the system classloader.

beanName - Name of a serialized bean or class name.

beanContext - Context to which the newly created Bean should be added.

initializer - The AppletInitializer which is used for initializing Applet beans.

Returns:

A newly created bean.

Throws:

IOException - If access of an IO resource failed.

ClassNotFoundException - If the class name is not known or does not lead to a proper bean class.

public static boolean isDesignTime()

Returns whether it is design time. Design time means we are in a RAD tool.

Defaults to false.

Returns:

whether it is design time.

public static boolean isGuiAvailable()

Returns whether the GUI is available to use.

Defaults to true.

Returns:

whether the GUI is available to use.

public static boolean isInstanceOf(Object bean,
                                   Class newBeanClass)

Determines whether the Bean can be cast to a different class type. This should be used instead of instanceof to determine a Bean's castability, because in the future there may be new types of Bean, even Beans spanning multiple Objects.

Parameters:

bean - the Bean to cast.

Returns:

whether the Bean can be cast to the class type in question.

public static void setDesignTime(boolean designTime)
            throws SecurityException

Sets whether it is design time. Design time means we are in a RAD tool.

Parameters:

designTime - whether it is design time.

public static void setGuiAvailable(boolean guiAvailable)
            throws SecurityException

Sets whether the GUI is available to use.

Parameters:

guiAvailable - whether the GUI is available to use.