/*
* Copyright 2014 Niclas Hedhman.
* Copyright 2014 Paul Merlin.
*
* 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.
*/
package org.qi4j.bootstrap.builder;
import java.util.ArrayList;
import java.util.List;
import org.qi4j.bootstrap.Assembler;
import org.qi4j.bootstrap.AssemblyException;
import org.qi4j.bootstrap.LayerAssembly;
import org.qi4j.bootstrap.ModuleAssembly;
import static org.qi4j.api.util.Classes.isAssignableFrom;
import static org.qi4j.functional.Iterables.filter;
import static org.qi4j.functional.Iterables.toList;
import static org.qi4j.functional.Specifications.not;
/**
* Provides declared {@link org.qi4j.api.structure.Module} information that the {@link ApplicationBuilder} can use.
*/
public class ModuleDeclaration
{
private final String moduleName;
private final List<Assembler> assemblers = new ArrayList<>();
private ModuleAssembly module;
public ModuleDeclaration( String moduleName )
{
this.moduleName = moduleName;
}
/**
* Declare Assembler.
* @param assembler Assembler instance
* @return This Module declaration
*/
public ModuleDeclaration withAssembler( Assembler assembler )
{
assemblers.add( assembler );
return this;
}
/**
* Declare Assembler.
* @param classname Assembler class name
* @return This Module declaration
* @throws AssemblyException if unable to load class, not an Assembler or unable to instanciate
*/
public ModuleDeclaration withAssembler( String classname )
throws AssemblyException
{
Class<? extends Assembler> clazz = loadClass( classname );
return withAssembler( clazz );
}
/**
* Declare Assembler.
* @param assemblerClass Assembler class
* @return This Module declaration
* @throws AssemblyException not an Assembler or if unable to instanciate
*/
public ModuleDeclaration withAssembler( Class<?> assemblerClass )
throws AssemblyException
{
Assembler assembler = createAssemblerInstance( assemblerClass );
assemblers.add( assembler );
return this;
}
/**
* Declare Assemblers.
* <p>Declare several Assemblers from an Iterable of Class objects.</p>
* <p>Typically used along {@link org.qi4j.bootstrap.ClassScanner}.</p>
* @param assemblerClasses Assembler classes
* @return This Module declaration
* @throws AssemblyException if one of the Class is not an Assembler or unable to instanciate
*/
public ModuleDeclaration withAssemblers( Iterable<Class<?>> assemblerClasses )
throws AssemblyException
{
List<Class<?>> notAssemblers = toList(
filter( not( isAssignableFrom( Assembler.class ) ),
assemblerClasses )
);
if( !notAssemblers.isEmpty() )
{
throw new AssemblyException(
"Classes " + notAssemblers + " are not implementing " + Assembler.class.getName()
);
}
for( Class<?> assemblerClass : assemblerClasses )
{
withAssembler( assemblerClass );
}
return this;
}
ModuleAssembly createModule( LayerAssembly layer )
{
module = layer.module( moduleName );
return module;
}
void initialize()
throws AssemblyException
{
for( Assembler assembler : assemblers )
{
assembler.assemble( module );
}
}
@SuppressWarnings( "unchecked" )
private Class<? extends Assembler> loadClass( String classname )
throws AssemblyException
{
Class<?> clazz;
try
{
clazz = getClass().getClassLoader().loadClass( classname );
}
catch( Exception e )
{
throw new AssemblyException( "Unable to load class " + classname, e );
}
if( !Assembler.class.isAssignableFrom( clazz ) )
{
throw new AssemblyException(
"Class " + classname + " is not implementing " + Assembler.class.getName()
);
}
//noinspection unchecked
return (Class<? extends Assembler>) clazz;
}
private Assembler createAssemblerInstance( Class<?> assemblerClass )
throws AssemblyException
{
if( !Assembler.class.isAssignableFrom( assemblerClass ) )
{
throw new AssemblyException(
"Class " + assemblerClass + " is not implementing " + Assembler.class.getName()
);
}
try
{
return (Assembler) assemblerClass.newInstance();
}
catch( Exception e )
{
throw new AssemblyException( "Unable to instantiate " + assemblerClass, e );
}
}
}