Hibernate example source code file (NativeScanner.java)

This example Hibernate source code file (NativeScanner.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

annotation, assertionfailure, entry, hashset, improper, io, ioexception, jarvisitor, jarvisitor, nativescanner, net, network, set, set, statejarvisitor, statejarvisitor, string, string, util

The Hibernate NativeScanner.java source code

/*
 * Copyright (c) 2009, Red Hat Middleware LLC or third-party contributors as
 * indicated by the @author tags or express copyright attribution
 * statements applied by the authors.  All third-party contributions are
 * distributed under license by Red Hat Middleware LLC.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.ejb.packaging;
import java.io.IOException;
import java.lang.annotation.Annotation;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import javax.persistence.Embeddable;
import javax.persistence.Entity;
import javax.persistence.MappedSuperclass;
import org.hibernate.AssertionFailure;
import org.hibernate.internal.util.ReflectHelper;

/**
 * @author Emmanuel Bernard
 */
public class NativeScanner implements Scanner {

	private static final String META_INF_ORM_XML = "META-INF/orm.xml";

	private Map<URL, StateJarVisitor> visitors = new HashMap();
	private static final int PACKAGE_FILTER_INDEX = 0;
	private static final int CLASS_FILTER_INDEX = 1;
	private static final int FILE_FILTER_INDEX = 2;

	/**
	 * This implementation does not honor the list of annotations and return everything.
	 * Must strictly be used by HEM
	 */
	public Set<Package> getPackagesInJar(URL jarToScan, Set> annotationsToLookFor) {
		if ( annotationsToLookFor.size() > 0 ) {
			throw new AssertionFailure( "Improper use of NativeScanner: must not filter packages" );
		}

		JarVisitor jarVisitor = getVisitor( jarToScan );
		final Set<Entry> packageEntries;
		try {
			packageEntries = ( Set<Entry> ) jarVisitor.getMatchingEntries()[PACKAGE_FILTER_INDEX];
		}
		catch ( IOException e ) {
			throw new RuntimeException( "Error while reading " + jarToScan.toString(), e );
		}
		Set<Package> packages = new HashSet( packageEntries.size() );
		for ( Entry entry : packageEntries ) {
			try {
				packages.add( ReflectHelper.classForName( entry.getName() + ".package-info" ).getPackage() );
			}
			catch ( ClassNotFoundException e ) {
				//should never happen, if it happens, simply ignore the flawed package
			}
		}
		return packages;
	}

	/**
	 * Build a JarVisitor with some assumptions wrt the scanning
	 * This helps do one scan instead of several
	 */
	private JarVisitor getVisitor(URL jar) {
		StateJarVisitor stateJarVisitor = visitors.get( jar );

		if ( stateJarVisitor == null ) {

			Filter[] filters = new Filter[3];
			filters[PACKAGE_FILTER_INDEX] = new PackageFilter( false, null ) {
				public boolean accept(String javaElementName) {
					return true;
				}
			};
			filters[CLASS_FILTER_INDEX] = new ClassFilter(
					false, new Class[] {
							Entity.class,
							MappedSuperclass.class,
							Embeddable.class
					}
			) {
				public boolean accept(String javaElementName) {
					return true;
				}
			};
			filters[FILE_FILTER_INDEX] = new FileFilter( true ) {
				public boolean accept(String javaElementName) {
					return javaElementName.endsWith( "hbm.xml" )
							|| javaElementName.endsWith( META_INF_ORM_XML );
				}
			};

			stateJarVisitor = new StateJarVisitor( JarVisitorFactory.getVisitor( jar, filters ) );
			visitors.put( jar, stateJarVisitor );
		}
		return stateJarVisitor.visitor;
	}

	public Set<Class getClassesInJar(URL jarToScan, Set> annotationsToLookFor) {
		if ( isValidForClasses( annotationsToLookFor ) ) {
			throw new AssertionFailure(
					"Improper use of NativeScanner: "
							+ "must not filter classes by other annotations than Entity, MappedSuperclass, embeddable"
			);
		}
		JarVisitor jarVisitor = getVisitor( jarToScan );
		final Set<Entry> classesEntry;
		try {
			classesEntry = ( Set<Entry> ) jarVisitor.getMatchingEntries()[CLASS_FILTER_INDEX];
		}
		catch ( IOException e ) {
			throw new RuntimeException( "Error while reading " + jarToScan.toString(), e );
		}
		Set<Class classes = new HashSet>( classesEntry.size() );
		for ( Entry entry : classesEntry ) {
			try {
				classes.add( ReflectHelper.classForName( entry.getName() ) );
			}
			catch ( ClassNotFoundException e ) {
				//should never happen, if it happens, simply ignore the flawed package
			}
		}
		return classes;
	}

	private boolean isValidForClasses(Set<Class annotationsToLookFor) {
		return annotationsToLookFor.size() != 3
				|| !annotationsToLookFor.contains( Entity.class )
				|| !annotationsToLookFor.contains( MappedSuperclass.class )
				|| !annotationsToLookFor.contains( Embeddable.class );
	}

	/**
	 * support for patterns is primitive:
	 * - **\/*.hbm.xml
	 * Other patterns will not be found
	 */
	public Set<NamedInputStream> getFilesInJar(URL jarToScan, Set filePatterns) {
		StringBuilder sb = new StringBuilder("URL: ").append( jarToScan )
				.append( "\n" );
		for (String pattern : filePatterns) {
			sb.append( "  " ).append( pattern ).append( "\n" );
		}
		JarVisitor jarVisitor = getVisitor( jarToScan );

		//state visitor available
		final StateJarVisitor stateVisitor = visitors.get( jarToScan );
		if ( stateVisitor.hasReadFiles ) {
			throw new AssertionFailure( "Cannot read files twice on NativeScanner" );
		}
		stateVisitor.hasReadFiles = true;
		
		Set<String> endWiths = new HashSet();
		Set<String> exacts = new HashSet();
		for ( String pattern : filePatterns ) {
			if ( pattern.startsWith( "**/*" ) ) {
				final String patternTail = pattern.substring( 4, pattern.length() );
				if ( !patternTail.equals( ".hbm.xml" ) ) {
					throw new AssertionFailure(
							"Improper use of NativeScanner: "
									+ "must not filter files via pattern other than .hbm.xml"
					);
				}
				endWiths.add( patternTail );
			}
			else {
				exacts.add( pattern );
			}
		}

		final Set<Entry> fileEntries;
		try {
			fileEntries = ( Set<Entry> ) jarVisitor.getMatchingEntries()[FILE_FILTER_INDEX];
		}
		catch ( IOException e ) {
			throw new RuntimeException( "Error while reading " + jarToScan.toString(), e );
		}
		Set<NamedInputStream> files = new HashSet( fileEntries.size() );
		Set<Entry> leftOver = new HashSet( fileEntries );
		for ( Entry entry : fileEntries ) {
			boolean done = false;
			for ( String exact : exacts ) {
				if ( entry.getName().equals( exact ) ) {
					files.add( new NamedInputStream( entry.getName(), entry.getInputStream() ) );
					leftOver.remove( entry );
					done = true;
				}
			}
			if (done) continue;
			for ( String endWithPattern : endWiths ) {
				if ( entry.getName().endsWith( endWithPattern ) ) {
					files.add( new NamedInputStream( entry.getName(), entry.getInputStream() ) );
					leftOver.remove( entry );
				}
			}

		}
		for ( Entry entry : leftOver ) {
			try {
				entry.getInputStream().close();
			}
			catch ( IOException e ) {
				//swallow as we don't care about these files
			}
		}
		return files;
	}

	public Set<NamedInputStream> getFilesInClasspath(Set filePatterns) {
		throw new AssertionFailure( "Not implemented" );
	}

	public String getUnqualifiedJarName(URL jarToScan) {
		JarVisitor jarVisitor = getVisitor( jarToScan );
		return jarVisitor.getUnqualifiedJarName();
	}

	private static class StateJarVisitor {
		StateJarVisitor(JarVisitor visitor) {
			this.visitor = visitor;
		}
		JarVisitor visitor;
		boolean hasReadFiles = false;
	}
}