public class CommandInfo extends ObjectThe CommandInfo class is used by CommandMap implementations to describe the results of command requests. It provides the requestor with both the verb requested, as well as an instance of the bean. There is also a method that will return the name of the class that implements the command but it is not guaranteed to return a valid value. The reason for this is to allow CommandMap implmentations that subclass CommandInfo to provide special behavior. For example a CommandMap could dynamically generate JavaBeans. In this case, it might not be possible to create an object with all the correct state information solely from the class name.
All Methods Instance Methods Concrete Methods Modifier and Type Method Description
getCommandClass()Return the command's class name.
getCommandName()Return the command verb.
getCommandObject(DataHandler dh, ClassLoader loader)Return the instantiated JavaBean component.
public String getCommandName()Return the command verb.
- the command verb.
public String getCommandClass()Return the command's class name. This method MAY return null in cases where a CommandMap subclassed CommandInfo for its own purposes. In other words, it might not be possible to create the correct state in the command by merely knowing its class name. DO NOT DEPEND ON THIS METHOD RETURNING A VALID VALUE!
- The class name of the command, or null
public Object getCommandObject(DataHandler dh, ClassLoader loader) throws IOException, ClassNotFoundExceptionReturn the instantiated JavaBean component.
java.beans.Beansis visible then it's
java.beans.Beans#instantiatemethod is invoked to instantiate the component as a JavaBeans component. When
java.beans.Beansis not visible (when
java.desktopmodule is not readable or when the runtime image does not contain the
java.desktopmodule) then the command's class is loaded and instantiated with its public no-args constructor.
The component class needs to be public.
If the bean implements the
javax.activation.CommandObjectinterface, call its
If the DataHandler parameter is null, then the bean is instantiated with no data. NOTE: this may be useful if for some reason the DataHandler that is passed in throws IOExceptions when this method attempts to access its InputStream. It will allow the caller to retrieve a reference to the bean if it can be instantiated.
If the bean does NOT implement the CommandObject interface, this method will check if it implements the java.io.Externalizable interface. If it does, the bean's readExternal method will be called if an InputStream can be acquired from the DataHandler.
dh- The DataHandler that describes the data to be passed to the command.
loader- The ClassLoader to be used to instantiate the bean.
- The bean
IOException- for failures reading data
ClassNotFoundException- if command object class can't be found
- See Also: