package org.apache.beehive.controls.runtime.assembly;
/*
* Copyright 2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* $Header:$
*/
import org.apache.beehive.controls.api.bean.ControlImplementation;
import org.apache.beehive.controls.api.assembly.ControlAssemblyContext;
import org.apache.beehive.controls.api.assembly.ControlAssemblyException;
import org.apache.beehive.controls.api.assembly.ControlAssembler;
import org.apache.beehive.controls.api.assembly.DefaultControlAssembler;
import java.io.File;
import java.io.IOException;
import java.util.Map;
import java.util.Set;
/**
* Helper class to execute assembly logic.
*/
public class Assembler
{
/**
* Executes basic assembly algorithm. For each control type & impl specified, query each impl for the presence
* of an assembler -- for each assembler present, build the specified ControlAssemblyContext implementation,
* create an instance of the assembler and execute it.
*
* @param moduleRoot dir root of the module
* @param moduleName name of the module
* @param srcOutputRoot dir where assemblers can output source files
* @param factoryName name of the ControlAssemblyContext factory to use
* @param controlTypeToImpl map of control type name to control impl for all control types to be assembled in this module
* @param controlTypeToClients map of control type name to a set of control clients (in this module) that use this type
* @param cl classloader used to load factories and assemblers
* @throws ControlAssemblyException
* @throws IOException
*/
public static void assemble( File moduleRoot,
String moduleName,
File srcOutputRoot,
String factoryName,
Map<String,String> controlTypeToImpl,
Map<String,Set<String>> controlTypeToClients,
ClassLoader cl )
throws ControlAssemblyException, IOException
{
if ( !moduleRoot.exists() || !srcOutputRoot.exists() )
throw new IOException( "Directories " + moduleRoot + " or " + srcOutputRoot + " don't exist!");
if ( factoryName == null )
throw new ControlAssemblyException( "Missing context factory names" );
if ( cl == null )
throw new ControlAssemblyException( "Must specify a classloader" );
ClassLoader origCL = Thread.currentThread().getContextClassLoader();
Thread.currentThread().setContextClassLoader( cl );
try
{
// Create the requested ControlAssemblyContext.Factory
Class factoryClass = cl.loadClass( factoryName );
ControlAssemblyContext.Factory factory = (ControlAssemblyContext.Factory)factoryClass.newInstance();
// Iterate over control types
Set<String> controlTypes = controlTypeToImpl.keySet();
for ( String ct : controlTypes )
{
// Search for applicable ControlAssemblers as specified on the control impls
String cImpl = controlTypeToImpl.get( ct );
Class cImplClass = cl.loadClass( cImpl );
ControlImplementation a = (ControlImplementation)cImplClass.getAnnotation(ControlImplementation.class);
if ( a == null )
throw new ControlAssemblyException( "Control implementation class=" + cImpl + " missing ControlImplementation annotation" );
// For each non-default ControlAssembler, create one and call it.
Class<? extends ControlAssembler> assemblerClass = a.assembler();
if ( !assemblerClass.equals(DefaultControlAssembler.class) )
{
ControlAssembler assembler = assemblerClass.newInstance();
Set<String> clients = controlTypeToClients.get( ct );
ControlAssemblyContext cac = factory.newInstance(
cl.loadClass(ct), null, clients, moduleRoot, moduleName, srcOutputRoot );
assembler.assemble( cac );
}
}
}
catch ( ControlAssemblyException cae )
{
// just rethrow ControlAssemblyExceptions, which will typically come from user-provided assemblers.
throw cae;
}
catch ( Throwable t )
{
// Not expecting any throwables other than ControlAssemblyExceptions, so consider them as
// unexpected infrastructure issues and wrap them in a CAE.
throw new ControlAssemblyException( "Assembly infrastructure exception", t);
}
finally
{
Thread.currentThread().setContextClassLoader( origCL );
}
}
}