donaldp 01/04/24 22:25:03
Modified: src/java/org/apache/avalon/atlantis
AbstractSystemManager.java
Log:
Implement some functionality into AbstractSystemManager
This does all the standard checking/exporting and has template methods that
subclasses should implement.
Revision Changes Path
1.2 +149 -9
jakarta-avalon-phoenix/src/java/org/apache/avalon/atlantis/AbstractSystemManager.java
Index: AbstractSystemManager.java
===================================================================
RCS file:
/home/cvs/jakarta-avalon-phoenix/src/java/org/apache/avalon/atlantis/AbstractSystemManager.java,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- AbstractSystemManager.java 2001/04/25 03:17:48 1.1
+++ AbstractSystemManager.java 2001/04/25 05:25:03 1.2
@@ -7,6 +7,7 @@
*/
package org.apache.avalon.atlantis;
+import java.util.HashMap;
import org.apache.avalon.logger.AbstractLoggable;
/**
@@ -18,6 +19,20 @@
extends AbstractLoggable
implements SystemManager
{
+ protected final static class ManagedEntry
+ {
+ ///Object passed in for management
+ protected Object m_object;
+
+ ///Interfaces object wants to be managed through (can be null)
+ protected Class[] m_interfaces;
+
+ ///Object representation when exported (usually a proxy)
+ protected Object m_exportedObject;
+ }
+
+ private HashMap m_entrys = new HashMap();
+
/**
* Register an object for management.
* The object is exported through some management scheme
@@ -27,13 +42,28 @@
* @param name the name to register object under
* @param object the object
* @param interfaces the interfaces to register the component under
- * @exception Exception if an error occurs. An error could occur if the object
doesn't
+ * @exception ManagerException if an error occurs. An error could occur if the
object doesn't
* implement the interfaces, the interfaces parameter contain
non-instance
* classes, the name is already registered etc.
+ * @exception IllegalArgumentException if object or interfaces is null
*/
- public void register( final String name, final Object object, final Class[]
interfaces )
- throws Exception
+ public synchronized void register( final String name, final Object object,
final Class[] interfaces )
+ throws ManagerException, IllegalArgumentException
{
+ checkRegister( name, object );
+ if( null == interfaces )
+ {
+ throw new IllegalArgumentException( "Null interfaces parameter" );
+ }
+
+ verifyInterfaces( object, interfaces );
+
+ final ManagedEntry entry = new ManagedEntry();
+ entry.m_object = object;
+ entry.m_interfaces = interfaces;
+ entry.m_exportedObject = export( name, entry.m_object, interfaces );
+
+ m_entrys.put( name, entry );
}
/**
@@ -43,21 +73,131 @@
*
* @param name the name to register object under
* @param object the object
- * @exception Exception if an error occurs such as name being already
registered.
+ * @exception ManagerException if an error occurs such as name already
registered.
+ * @exception IllegalArgumentException if object is null
*/
- public void register( final String name, final Object object )
- throws Exception
+ public synchronized void register( final String name, final Object object )
+ throws ManagerException, IllegalArgumentException
{
+ checkRegister( name, object );
+
+ final ManagedEntry entry = new ManagedEntry();
+ entry.m_object = object;
+ entry.m_interfaces = null;
+ entry.m_exportedObject = export( name, entry.m_object, null );
+
+ m_entrys.put( name, entry );
}
/**
* Unregister named object.
*
* @param name the name of object to unregister
- * @exception Exception if an error occurs such as when no such object
registered.
+ * @exception ManagerException if an error occurs such as when no such object
registered.
*/
- public void unregister( final String name )
- throws Exception
+ public synchronized void unregister( final String name )
+ throws ManagerException
{
+ final ManagedEntry entry = (ManagedEntry)m_entrys.remove( name );
+
+ if( null == entry )
+ {
+ throw new ManagerException( "No such entry" );
+ }
+
+ unexport( name, entry.m_exportedObject );
+ }
+
+ /**
+ * Export the object to the particular management medium using
+ * the supplied object and interfaces.
+ * This needs to be implemented by subclasses.
+ *
+ * @param name the name of object
+ * @param object the object
+ * @param interfaces the interfaces
+ * @return the exported object
+ * @exception ManagerException if an error occurs
+ */
+ protected abstract Object export( String name, Object object, Class[]
interfaces )
+ throws ManagerException;
+
+ /**
+ * Stop the exported object from being managed.
+ *
+ * @param name the name of object
+ * @param exportedObject the object return by export
+ * @exception ManagerException if an error occurs
+ */
+ protected abstract void unexport( String name, Object exportedObject )
+ throws ManagerException;
+
+ /**
+ * Verify that an interface conforms to the requirements of management medium.
+ *
+ * @param clazz the interface class
+ * @exception ManagerException if verification fails
+ */
+ protected abstract void verifyInterface( Class clazz )
+ throws ManagerException;
+
+ /**
+ * Verify that object implements interfaces and interfaces are of "acceptable
form".
+ * "Acceptable form" is determined by specific management policy.
+ *
+ * @param object the object
+ * @param interfaces the array of interfaces to check
+ * @exception ManagerException if an error occurs
+ */
+ private void verifyInterfaces( final Object object, final Class[] interfaces )
+ throws ManagerException
+ {
+ for( int i = 0; i < interfaces.length; i++ )
+ {
+ final Class clazz = interfaces[ i ];
+
+ if( !clazz.isInterface() )
+ {
+ throw new ManagerException( "Can not export " + clazz.getName() +
+ " for management as it is not an
interface" );
+ }
+
+ if( !clazz.isInstance( object ) )
+ {
+ throw new ManagerException( "Can not export " + clazz.getName() +
+ " for management as object does not " +
+ "implement interface" );
+ }
+
+ verifyInterface( clazz );
+ }
+ }
+
+ /**
+ * Helper method to help check before an objects registration.
+ * Verifies name and object are not null and verifies no entry exists using
name.
+ *
+ * @param name the name of object
+ * @param object the object to be registered
+ * @exception ManagerException if name already exists
+ * @exception IllegalArgumentException if name or object is null
+ */
+ private void checkRegister( final String name, final Object object )
+ throws ManagerException, IllegalArgumentException
+ {
+ if( null == object )
+ {
+ throw new IllegalArgumentException( "Null object parameter" );
+ }
+
+ if( null == name )
+ {
+ throw new IllegalArgumentException( "Null name parameter" );
+ }
+
+ if( null != m_entrys.get( name ) )
+ {
+ throw new ManagerException( "Entry already exisits" );
+ }
}
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
