diff options
Diffstat (limited to 'sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/java/impl/ContributionClassLoader.java')
| -rw-r--r-- | sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/java/impl/ContributionClassLoader.java | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/java/impl/ContributionClassLoader.java b/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/java/impl/ContributionClassLoader.java new file mode 100644 index 0000000000..25b3eae350 --- /dev/null +++ b/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/java/impl/ContributionClassLoader.java @@ -0,0 +1,386 @@ +/* + * 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.tuscany.sca.contribution.java.impl; + +import java.io.IOException; +import java.net.MalformedURLException; +import java.net.URL; +import java.net.URLClassLoader; +import java.util.Collection; +import java.util.Collections; +import java.util.Enumeration; +import java.util.HashSet; + +import org.apache.tuscany.sca.contribution.Contribution; +import org.apache.tuscany.sca.contribution.Export; +import org.apache.tuscany.sca.contribution.Import; +import org.apache.tuscany.sca.contribution.java.JavaImport; + + +public class ContributionClassLoader extends URLClassLoader { +// public class ContributionClassLoader { + + private Contribution contribution; + // private b urlClassLoader; + + /** + * Constructor for contribution ClassLoader + * + * @param contribution + * @param parent + * @throws MalformedURLException + */ + public ContributionClassLoader(Contribution contribution, final ClassLoader parent) { + super(new URL[0], parent); + // Note that privileged use of getContextClassLoader have been promoted to callers. + // super(new URL[0], parent == null?Thread.currentThread().getContextClassLoader(): null); + this.contribution = contribution; + if (contribution.getLocation() != null) { + try { + this.addURL(new URL(contribution.getLocation())); + for (URL url : ContributionHelper.getNestedJarUrls(contribution)) { + this.addURL(url); + } + } catch (IOException e) { + throw new RuntimeException(e); + } + } + } + + /* + * Return the ClassLoader corresponding to a contribution providing an export + * Create a new ClassLoader for the contribution if one does not exist + */ + private ClassLoader getExportClassLoader(Contribution exportingContribution) { + ClassLoader cl = exportingContribution.getClassLoader(); + if (!(cl instanceof ContributionClassLoader)) { + if (cl == null) { + cl = getParent(); + } + + cl = new ContributionClassLoader(exportingContribution, cl); + exportingContribution.setClassLoader(cl); + } + return cl; + } + + /* (non-Javadoc) + * @see java.net.URLClassLoader#findClass(java.lang.String) + * + * Search path for class: + * This contribution + * Imported contributions + */ + @Override + protected Class<?> findClass(String className) throws ClassNotFoundException { + + Class<?> clazz = null; + try { + clazz = findClassFromContribution(className); + } catch (ClassNotFoundException e) { + + for (Import import_ : this.contribution.getImports()) { + if (classNameMatchesImport(className, import_)) { + // Delegate the resolution to the imported contribution + for (Contribution exportingContribution : ((JavaImportModelResolver)import_.getModelResolver()).getExportContributions()) { + + ClassLoader exportClassLoader = getExportClassLoader(exportingContribution); + if (exportClassLoader instanceof ContributionClassLoader) { + + for (Export export : exportingContribution.getExports()) { + try { + if (import_.match(export)) { + clazz = ((ContributionClassLoader)exportClassLoader).findClassFromContribution(className); + break; + } + } catch (ClassNotFoundException e1) { + continue; + } + + } + if (clazz != null) break; + } + } + if (clazz != null) break; + } + } + + if (clazz == null) throw e; + } + return clazz; + } + + + /* (non-Javadoc) + * @see java.lang.ClassLoader#loadClass(java.lang.String, boolean) + * + * Search path for class: + * Parent ClassLoader + * This contribution + * Imported contributions + * + */ + @Override + protected synchronized Class<?> loadClass(String className, boolean resolveClass) + throws ClassNotFoundException { + + Class<?> clazz = null; + try { + + if (this.getParent() != null) + clazz = this.getParent().loadClass(className); + + } catch (ClassNotFoundException e) { + } + + if (clazz == null) + clazz = findClass(className); + + + if (resolveClass) + this.resolveClass(clazz); + return clazz; + + } + + + + /* + * (non-Javadoc) + * + * @see java.net.URLClassLoader#findResource(java.lang.String) + */ + @Override + public URL findResource(String name) { + + URL url = findResourceFromContribution(name); + + if (url == null) { + for (Import import_ : this.contribution.getImports()) { + if (resourceNameMatchesImport(name, import_)) { + // Delegate the resolution to the imported contribution + for (Contribution exportingContribution : ((JavaImportModelResolver)import_.getModelResolver()).getExportContributions()) { + + ClassLoader exportClassLoader = getExportClassLoader(exportingContribution); + if (exportClassLoader instanceof ContributionClassLoader) { + + for (Export export : exportingContribution.getExports()) { + if (import_.match(export)) { + url = ((ContributionClassLoader)exportClassLoader).findResourceFromContribution(name); + if (url != null) break; + } + } + if (url != null) break; + } + } + if (url != null) break; + } + } + + } + return url; + } + + + /* (non-Javadoc) + * @see java.net.URLClassLoader#findResources(java.lang.String) + */ + @Override + public Enumeration<URL> findResources(String name) throws IOException { + + return Collections.enumeration(findResourceSet(name)); + } + + + + + /* (non-Javadoc) + * @see java.lang.ClassLoader#getResource(java.lang.String) + * + * Find a resource. + * Search path for resource: + * Parent ClassLoader + * This contribution + * Imported contributions + */ + @Override + public URL getResource(String resName) { + + URL resource = null; + + if (this.getParent() != null) { + resource = this.getParent().getResource(resName); + } + if (resource == null) + resource = findResource(resName); + + return resource; + } + + + + /* (non-Javadoc) + * @see java.lang.ClassLoader#getResources(java.lang.String) + * + * Return list of resources from this contribution, resources + * imported through imported contributions and resources from parent + * ClassLoader. + */ + @Override + public Enumeration<URL> getResources(String resName) throws IOException { + + HashSet<URL> resourceSet = findResourceSet(resName); + addEnumerationToCollection(resourceSet, super.getResources(resName)); + + return Collections.enumeration(resourceSet); + } + + + /* + * Find set of resources + */ + private HashSet<URL> findResourceSet(String name) throws IOException { + + HashSet<URL> resources = new HashSet<URL>(); + + addEnumerationToCollection(resources, super.findResources(name)); + + for (Import import_ : this.contribution.getImports()) { + if (!(import_ instanceof JavaImport)) { + continue; + } + if (resourceNameMatchesImport(name, import_)) { + // Delegate the resolution to the imported contribution + for (Contribution exportingContribution : ((JavaImportModelResolver)import_.getModelResolver()).getExportContributions()) { + + ClassLoader exportClassLoader = getExportClassLoader(exportingContribution); + if (exportClassLoader instanceof ContributionClassLoader) { + + for (Export export : exportingContribution.getExports()) { + if (import_.match(export)) { + addEnumerationToCollection(resources, + ((ContributionClassLoader)exportClassLoader).findResources(name)); + } + } + } + } + } + } + + return resources; + } + + + /* + * Find class from contribution. If class has already been loaded, return loaded class. + */ + private Class<?> findClassFromContribution(String className) throws ClassNotFoundException { + + Class<?> clazz = findLoadedClass(className); + if (clazz == null) + clazz = super.findClass(className); + return clazz; + + } + + /* + * Find resource from contribution. + */ + private URL findResourceFromContribution(String name) { + + return super.findResource(name); + } + + /** + * Check if a class name matches an import statement. + * Class matches if the package name used in <import.java/> matches + * + * @param name Name of class + * @param import_ SCA contribution import + * @return true if this is a matching import + */ + private boolean classNameMatchesImport(String name, Import import_) { + + if (import_ instanceof JavaImport && name != null && name.lastIndexOf('.') > 0) { + JavaImport javaImport = (JavaImport) import_; + + String packageName = name.substring(0, name.lastIndexOf('.')); + if (javaImport.getPackage().endsWith(".*")) { + String prefix = javaImport.getPackage().substring(0, javaImport.getPackage().length() -1); + if (packageName.startsWith(prefix)) { + return true; + } + } else { + return packageName.equals(javaImport.getPackage()); + } + } + + return false; + } + + /** + * Check if a resource name matches an import statement. + * Resource matches if package/namespace match the directory of resource. + * + * @param name Name of resource + * @param import_ SCA contribution import + * @return true if this is a matching import + */ + private boolean resourceNameMatchesImport(String name, Import import_) { + + + if (name == null || name.lastIndexOf('/') <= 0) + return false; + else if (import_ instanceof JavaImport) { + JavaImport javaImport = (JavaImport) import_; + + if (javaImport.getPackage().endsWith(".*")) { + String packageName = name.substring(0, name.lastIndexOf('/')).replace('/', '.'); + String prefix = javaImport.getPackage().substring(0, javaImport.getPackage().length() -1); + if (packageName.startsWith(prefix)) { + return true; + } + } else { + // 'name' is a resource : contains "/" as separators + // Get package name from resource name + String packageName = name.substring(0, name.lastIndexOf('/')); + return packageName.equals(javaImport.getPackage().replaceAll("\\.", "/")); + } + } + return false; + } + + /* + * Add an enumeration to a Collection + */ + private <T extends Object> void addEnumerationToCollection(Collection<T> collection, Enumeration<T> enumeration) { + + while (enumeration.hasMoreElements()) + collection.add(enumeration.nextElement()); + } + + + @Override + public String toString() { + return "SCA Contribution ClassLoader location: " + contribution.getLocation() + " parent ClassLoader: " + getParent(); + } + + +} |