org.echocat.jomon.maven.OverwriteWithMavenResourcesClassLoader Maven / Gradle / Ivy
/*****************************************************************************************
* *** BEGIN LICENSE BLOCK *****
*
* Version: MPL 2.0
*
* echocat Jomon, Copyright (c) 2012-2013 echocat
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* *** END LICENSE BLOCK *****
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package org.echocat.jomon.maven;
import org.apache.commons.collections15.map.LRUMap;
import org.apache.maven.model.Resource;
import org.apache.maven.project.MavenProject;
import org.apache.maven.project.ProjectBuildingException;
import org.echocat.jomon.runtime.system.DynamicClassLoader;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.core.PriorityOrdered;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.PostConstruct;
import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.*;
import static com.google.common.collect.Iterators.*;
import static java.lang.System.setProperty;
import static java.lang.Thread.currentThread;
import static java.util.Collections.synchronizedMap;
import static org.springframework.util.CollectionUtils.isEmpty;
public class OverwriteWithMavenResourcesClassLoader extends ClassLoader implements PriorityOrdered, DynamicClassLoader {
private static final Logger LOG = LoggerFactory.getLogger(OverwriteWithMavenResourcesClassLoader.class);
private static final Map, Collection> ROOT_POMS_RESOURCE_ROOT_CACHE = synchronizedMap(new LRUMap, Collection>(10));
private final Map _resourceCache = synchronizedMap(new LRUMap(1000));
private Collection _rootPoms;
private boolean _setAsContextLoader;
private boolean _useJvmWideCaching;
private volatile Collection _resourceRoots;
public OverwriteWithMavenResourcesClassLoader(@Nonnull ClassLoader delegate) {
super(delegate);
}
@PostConstruct
public void init() throws Exception {
synchronized (this) {
final Collection rootPoms = _rootPoms;
if (!isEmpty(rootPoms)) {
final Set rootPomsAsCacheKey = new HashSet<>(rootPoms);
_resourceRoots = ROOT_POMS_RESOURCE_ROOT_CACHE.get(rootPomsAsCacheKey);
if (_resourceRoots == null || !_useJvmWideCaching) {
LOG.info("Found root poms " + rootPoms + ". Start to scan for usable resource roots...");
final List projects = toProjectsRecursively(rootPoms);
_resourceRoots = toResourceRoots(projects);
ROOT_POMS_RESOURCE_ROOT_CACHE.put(rootPomsAsCacheKey, rootPoms);
LOG.info("Found root poms " + rootPoms + ". Start to scan for usable resource roots... DONE!");
}
} else {
_resourceRoots = null;
}
if (_resourceRoots != null && !_resourceRoots.isEmpty()) {
setProperty("org.apache.jasper.options.development", "true");
setProperty("org.apache.jasper.options.checkInterval", "1");
}
}
if (_setAsContextLoader) {
currentThread().setContextClassLoader(this);
}
}
@Override
public URL getResource(@Nonnull String name) {
CacheEntry result;
synchronized (this) {
result = _resourceCache.get(name);
}
if (result == null) {
final Collection resourceRoots = _resourceRoots;
File resultFile = null;
if (resourceRoots != null) {
if (resultFile != null && !resultFile.isFile()) {
resultFile = null;
}
if (resultFile == null) {
if (resourceRoots != null) {
for (final File resourceRoot : resourceRoots) {
final File potentialResource = new File(resourceRoot, name);
if (potentialResource.isFile()) {
resultFile = potentialResource;
break;
}
}
}
}
}
if (resultFile != null) {
try {
result = new CacheEntry(resultFile, resultFile.toURI().toURL());
} catch (final MalformedURLException e) {
throw new RuntimeException(e);
}
} else {
final URL resource = super.getResource(name);
result = resource != null ? new CacheEntry(null, resource) : null;
}
synchronized (this) {
_resourceCache.put(name, result);
}
}
return result != null ? result.getUrl() : null;
}
@Override
public Enumeration getResources(@Nonnull String name) throws IOException {
final Collection resourceRoots = _resourceRoots;
final Enumeration result;
if (resourceRoots != null) {
final List foundStaticUrls = new ArrayList<>();
for (final File resourceRoot : resourceRoots) {
final File potentialResource = new File(resourceRoot, name);
if (potentialResource.isFile()) {
foundStaticUrls.add(potentialResource.toURI().toURL());
}
}
final Iterator combined = concat(foundStaticUrls.iterator(), forEnumeration(super.getResources(name)));
result = asEnumeration(combined);
} else {
result = super.getResources(name);
}
return result;
}
@Nonnull
protected List toProjectsRecursively(@Nonnull Collection rootPoms) throws Exception {
final List projects = new ArrayList<>();
final MavenEnvironment environment = new MavenEnvironmentFactory().create();
final MavenProjectWithModulesFactory factory = new MavenProjectWithModulesFactory();
for (final File rootPom : rootPoms) {
try {
final MavenProjectWithModules project = factory.createFor(environment, rootPom);
enrichWithAllModulesRecursively(projects, project);
} catch (final ProjectBuildingException e) {
LOG.warn("Could not build the project list for " + rootPom + ". Will ignore it now but this means that we could not erich the paths with it.", e);
}
}
return projects;
}
protected void enrichWithAllModulesRecursively(@Nonnull Collection what, @Nonnull MavenProjectWithModules withProject) throws Exception {
if (!what.contains(withProject)) {
what.add(withProject);
final Collection modules = withProject.getModules();
if (modules != null) {
for (final MavenProjectWithModules module : modules) {
enrichWithAllModulesRecursively(what, module);
}
}
}
}
@Nonnull
protected List toResourceRoots(@Nonnull List projects) throws Exception {
final List resourceRoots = new ArrayList<>();
for (final MavenProjectWithModules project : projects) {
final MavenProject mavenProject = project.getProject();
enrichWithResources(resourceRoots, mavenProject);
}
return resourceRoots;
}
protected void enrichWithResources(@Nonnull Collection what, @Nonnull MavenProject of) throws Exception {
final List resources = of.getResources();
if (resources != null) {
for (final Resource resource : resources) {
final String plainDirectory = resource.getDirectory();
if (plainDirectory != null) {
final File directory = new File(plainDirectory).getCanonicalFile();
if (directory.isDirectory() && !what.contains(directory)) {
what.add(directory);
}
}
}
}
}
public boolean isSetAsContextLoader() {
return _setAsContextLoader;
}
public void setSetAsContextLoader(boolean setAsContextLoader) {
_setAsContextLoader = setAsContextLoader;
}
public boolean isUseJvmWideCaching() {
return _useJvmWideCaching;
}
public void setUseJvmWideCaching(boolean useJvmWideCaching) {
_useJvmWideCaching = useJvmWideCaching;
}
public Collection getRootPoms() {
return _rootPoms;
}
public void setRootPoms(Collection rootPoms) {
_rootPoms = rootPoms;
}
@Override
public int getOrder() {
return HIGHEST_PRECEDENCE;
}
@Override
public boolean isDynamic() {
return _resourceRoots != null && !_resourceRoots.isEmpty();
}
protected static class CacheEntry {
private final File _file;
private final URL _url;
public CacheEntry(@Nullable File file, @Nonnull URL url) {
_file = file;
_url = url;
}
public File getFile() {
return _file;
}
public URL getUrl() {
return _url;
}
}
}
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