/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.jena.assembler.assemblers;
import java.util.List;
import org.apache.jena.assembler.* ;
import org.apache.jena.assembler.exceptions.* ;
import org.apache.jena.rdf.model.* ;
import org.apache.jena.shared.JenaException ;
import org.apache.jena.system.JenaSystem ;
import org.apache.jena.vocabulary.RDF ;
public abstract class AssemblerBase implements Assembler
{
static { JenaSystem.init(); }
@Override
public final Object open( Resource root )
{ return open( this, root ); }
@Override
public final Object open( Assembler a, Resource root )
{ return open( a, root, Mode.DEFAULT ); }
@Override
public abstract Object open( Assembler a, Resource root, Mode mode );
protected static Resource getUniqueResource( Resource root, Property property )
{ return (Resource) getUnique( root, property ); }
protected static Literal getUniqueLiteral( Resource root, Property property )
{ return (Literal) getUnique( root, property ); }
protected static Statement getUniqueStatement( Resource root, Property property )
{
List<Statement> statements = root.listProperties( property ).toList();
if (statements.size() == 0) return null;
if (statements.size() == 1) return statements.get(0);
throw new NotUniqueException( root, property );
}
protected static RDFNode getUnique( Resource root, Property property )
{
List<RDFNode> nodes = root.listProperties( property ) .mapWith( s -> s.getObject() ).toList();
if (nodes.size() == 0) return null;
if (nodes.size() == 1) return nodes.get(0);
throw new NotUniqueException( root, property );
}
protected void checkType( Resource root, Resource type )
{
if (!root.hasProperty( RDF.type, type ))
throw new CannotConstructException( this.getClass(), root, type );
}
@Override
public Model openModel( Resource root, Mode mode )
{ return (Model) open( this, root, mode ); }
@Override
public Model openModel( Resource root )
{ return openModel( root, Mode.DEFAULT ); }
public static Resource getRequiredResource( Resource root, Property p )
{
Resource R = getUniqueResource( root, p );
if (R == null) throw new PropertyRequiredException( root, p );
return R;
}
protected Literal getRequiredLiteral( Resource root, Property p )
{
Literal L = getUniqueLiteral( root, p );
if (L == null) throw new PropertyRequiredException( root, p );
return L;
}
protected static Resource getResource( Statement s )
{ return AssemblerHelp.getResource( s ); }
protected static String getString( Statement s )
{ return AssemblerHelp.getString( s ); }
protected static String getUniqueString( Resource root, Property property )
{
Statement s = getUniqueStatement( root, property );
return s == null ? null : AssemblerHelp.getString( s );
}
protected static Class<?> loadClass( Resource root, String className )
{
try
{ return Class.forName( className ); }
catch (ClassNotFoundException e)
{ throw new CannotLoadClassException( root, className, e ); }
}
/**
Answer the string described by the value of the unique optional
<code>classProperty</code> property of <code>root</code>,
or null if there's no such property. The value may be a URI, in which case
it must be a <b>java:</b> URI with content the class name; or it may
be a literal, in which case its lexical form is its class name; otherwise,
BOOM.
*/
public static String getOptionalClassName( Resource root, Property classProperty )
{
RDFNode classNode = getUnique( root, classProperty );
return
classNode == null ? null
: classNode.isLiteral() ? classNode.asNode().getLiteralLexicalForm()
: classNode.isResource() ? mustBeJava( classNode.asNode().getURI() )
: null
;
}
/**
Throw an exception if <code>uri</code> doesn't start with "java:",
otherwise answer the string beyond the ":".
*/
private static String mustBeJava( String uri )
{ // TODO replace JenaException
if (uri.startsWith( "java:" )) return uri.substring( 5 );
throw new JenaException( "class name URI must start with 'java:': " + uri );
}
}