openjpa-lib/src/main/java/org/apache/openjpa/lib/conf/ProductDerivations.java - openjpa - Git at Google

 /*
  * 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.openjpa.lib.conf;

 import java.io.File;
 import java.security.AccessController;
 import java.security.PrivilegedActionException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.MissingResourceException;
 import java.util.Set;
 import java.util.TreeSet;

 import org.apache.openjpa.lib.util.J2DoPrivHelper;
 import org.apache.openjpa.lib.util.Localizer;
 import org.apache.openjpa.lib.util.MultiClassLoader;
 import org.apache.openjpa.lib.util.Services;
 import org.apache.openjpa.lib.util.StringUtil;

 /**
  * Utilities for running product derivations.
  *
  * @author Abe White
  * @author Pinaki Poddar
  */
 public class ProductDerivations {

     private static final Localizer _loc = Localizer.forPackage
         (ProductDerivations.class);

     private static final ProductDerivation[] _derivations;
     private static final String[] _derivationNames;
     private static final Throwable[] _derivationErrors;
     private static String[] _prefixes;
     static {
         MultiClassLoader l = AccessController.doPrivileged(J2DoPrivHelper.newMultiClassLoaderAction());
         l.addClassLoader(0, AccessController
             .doPrivileged(J2DoPrivHelper.getClassLoaderAction(ProductDerivations.class)));
         l.addClassLoader(1, AccessController.doPrivileged(J2DoPrivHelper.getContextClassLoaderAction()));
         _derivationNames = Services.getImplementors(ProductDerivation.class, l);
         _derivationErrors = new Throwable[_derivationNames.length];
         List<ProductDerivation> derivations =
             new ArrayList<>(_derivationNames.length);
         boolean errors = false;
         for (int i = 0; i < _derivationNames.length; i++) {
             try {
                 ProductDerivation d = (ProductDerivation)
                     AccessController.doPrivileged(
                         J2DoPrivHelper.newInstanceAction(
                             Class.forName(_derivationNames[i], true, l)));
                 d.validate();
                 derivations.add(d);
             } catch (Throwable t) {
                 if (t instanceof PrivilegedActionException)
                     t = ((PrivilegedActionException) t).getException();
                 _derivationErrors[i] = t;
                 errors = true;
             }
         }

         // must be at least one product derivation to define metadata factories,
         // etc.
         if (derivations.isEmpty()) {
             throw new MissingResourceException(_loc.get
                 ("no-product-derivations", ProductDerivation.class.getName(),
                 derivationErrorsToString()).getMessage(),
                 ProductDerivations.class.getName(),"derivations");
         }

         // START - ALLOW PRINT STATEMENTS
         // if some derivations weren't instantiable, warn
         if (errors)
             System.err.println(_loc.get("bad-product-derivations",
                 ProductDerivations.class.getName()));
         for (int i = 0; i < _derivationErrors.length; i++) {
             if (_derivationErrors[i] == null)
                 continue;
             System.err.println(_derivationNames[i] + ":" +
                     _derivationErrors[i]);
             break;
         }
         // STOP - ALLOW PRINT STATEMENTS

         Collections.sort(derivations, new ProductDerivationComparator());
         _derivations =
             derivations.toArray(new ProductDerivation[derivations.size()]);

         List<String> prefixes = new ArrayList<>(2);
         prefixes.add("openjpa");
         for (ProductDerivation derivation : _derivations) {
             String prefix = derivation.getConfigurationPrefix();
             if (prefix != null && !"openjpa".equals(prefix))
                 prefixes.add(prefix);
         }
         _prefixes = prefixes.toArray(new String[prefixes.size()]);
     }

     /**
      * Return all the product derivations registered in the current classloader
      */
     public static ProductDerivation[] getProductDerivations() {
         return _derivations;
     }

     /**
      * Return the recognized prefixes for configuration properties.
      */
     public static String[] getConfigurationPrefixes() {
         return _prefixes;
     }

     /**
      * Set the configuration prefix array. This is package-visible for
      * testing purposes.
      *
      * @since 0.9.7
      */
     static void setConfigurationPrefixes(String[] prefixes) {
         _prefixes = prefixes;
     }

     /**
      * Determine the full key name for <code>partialKey</code>, given the
      * registered prefixes and the entries in <code>map</code>. This method
      * computes the appropriate configuration prefix to use by looking
      * through <code>map</code> for a key starting with any of the known
      * configuration prefixes and ending with <code>partialKey</code> and, if a
      * value is found, using the prefix of that key. Otherwise, it uses
      * the first registered prefix.
      *
      * The given <code>partialKey</code> is first tested for containment in the
      * given map without any prefix.
      *
      * @since 0.9.7
      */
     public static String getConfigurationKey(String partialKey, Map map) {
         String firstKey = (map != null && map.containsKey(partialKey))
             ? partialKey : null;
         for (int i = 0; map != null && i < _prefixes.length; i++) {
             String fullKey = _prefixes[i] + "." + partialKey;
             if (map.containsKey(fullKey)) {
                 if (firstKey == null)
                     firstKey = fullKey;
                 else {
                     // if we've already found a property with a previous
                     // prefix, then this is a collision.
                     throw new IllegalStateException(_loc.get(
                         "dup-with-different-prefixes", firstKey, fullKey)
                         .getMessage());
                 }
             }
         }

         if (firstKey == null)
             return _prefixes[0] + "." + partialKey;
         else
             return firstKey;
     }

     /**
      * Apply {@link ProductDerivation#beforeConfigurationConstruct} callbacks
      * to the the given instance. Exceptions other than fatal
      * {@link BootstrapException} are swallowed.
      */
     public static void beforeConfigurationConstruct(ConfigurationProvider cp) {
         for (ProductDerivation derivation : _derivations) {
             try {
                 derivation.beforeConfigurationConstruct(cp);
             }
             catch (BootstrapException be) {
                 if (be.isFatal())
                     throw be;
             }
             catch (Exception e) {
                 // can't log; no configuration yet
                 e.printStackTrace();
             }
         }
     }

     /**
      * Apply {@link ProductDerivation#beforeConfigurationLoad} callbacks
      * to the the given instance. Exceptions other than fatal
      * {@link BootstrapException} are swallowed.
      */
     public static void beforeConfigurationLoad(Configuration conf) {
         for (ProductDerivation derivation : _derivations) {
             try {
                 derivation.beforeConfigurationLoad(conf);
             }
             catch (BootstrapException be) {
                 if (be.isFatal())
                     throw be;
             }
             catch (Exception e) {
                 // logging not configured yet
                 e.printStackTrace();
             }
         }
     }

     /**
      * Apply {@link ProductDerivation#afterSpecificationSet} callbacks
      * to the the given instance. Exceptions other than fatal
      * {@link BootstrapException} are swallowed.
      */
     public static void afterSpecificationSet(Configuration conf) {
         for (ProductDerivation derivation : _derivations) {
             try {
                 derivation.afterSpecificationSet(conf);
             }
             catch (BootstrapException be) {
                 if (be.isFatal())
                     throw be;
             }
             catch (Exception e) {
                 // logging not configured yet
                 e.printStackTrace();
             }
         }
     }

     /**
      * Called as the first step of a Configuration's close() method.
      * Exceptions are swallowed.
      *
      * @since 0.9.7
      */
     public static void beforeClose(Configuration conf) {
         for (ProductDerivation derivation : _derivations) {
             try {
                 derivation.beforeConfigurationClose(conf);
             }
             catch (Exception e) {
                 conf.getConfigurationLog().warn(_loc.get("before-close-ex"), e);
             }
         }
     }

     /**
      * Load the given given resource, or return false if it is not a resource
      * this provider understands. The given class loader may be null.
      *
      * @param anchor optional named anchor within a multiple-configuration
      * resource
      */
     public static ConfigurationProvider load(String resource, String anchor,
         ClassLoader loader) {
         if (StringUtil.isEmpty(resource))
             return null;
         if (loader == null)
             loader = AccessController.doPrivileged(
                 J2DoPrivHelper.getContextClassLoaderAction());
         ConfigurationProvider provider = null;
         StringBuilder errs = null;
         // most specific to least
         Throwable err = null;
         for (int i = _derivations.length - 1; i >= 0; i--) {
             try {
                 provider = _derivations[i].load(resource, anchor, loader);
                 if (provider != null)
                     return provider;
             } catch (Throwable t) {
                 err = t;
                 errs = (errs == null) ? new StringBuilder() : errs.append("\n");
                 errs.append(_derivations[i].getClass().getName() + ":" + t);
             }
         }
         reportErrors(errs, resource, err);
         String rsrc = resource + "#" + anchor;
         MissingResourceException ex = new MissingResourceException(rsrc,
                 ProductDerivations.class.getName(), rsrc);
         ex.initCause(err);
         throw ex;
     }

     /**
      * Load given file, or return false if it is not a file this provider
      * understands.
      *
      * @param anchor optional named anchor within a multiple-configuration file
      */
     public static ConfigurationProvider load(File file, String anchor,
         ClassLoader loader) {
         if (file == null)
             return null;
         if (loader == null)
             loader = AccessController.doPrivileged(
                 J2DoPrivHelper.getContextClassLoaderAction());
         ConfigurationProvider provider = null;
         StringBuilder errs = null;
         Throwable err = null;
         // most specific to least
         for (int i = _derivations.length - 1; i >= 0; i--) {
             try {
                 provider = _derivations[i].load(file, anchor);
                 if (provider != null)
                     return provider;
             } catch (Throwable t) {
                 err = t;
                 errs = (errs == null) ? new StringBuilder() : errs.append("\n");
                 errs.append(_derivations[i].getClass().getName() + ":" + t);
             }
         }
         String aPath = AccessController.doPrivileged(
             J2DoPrivHelper.getAbsolutePathAction(file));
         reportErrors(errs, aPath, err);
         String rsrc = aPath + "#" + anchor;
         MissingResourceException ex = new MissingResourceException(rsrc,
                 ProductDerivations.class.getName(), rsrc);
         ex.initCause(err);
         throw ex;
     }

     /**
      * Return a {@link ConfigurationProvider} that has parsed system defaults.
      */
     public static ConfigurationProvider loadDefaults(ClassLoader loader) {
         return load(loader, false);
     }

     /**
      * Return a {@link ConfigurationProvider} that has parsed system globals.
      */
     public static ConfigurationProvider loadGlobals(ClassLoader loader) {
         return load(loader, true);
     }

     /**
      * Load a built-in resource location.
      */
     private static ConfigurationProvider load(ClassLoader loader,
        boolean globals) {
         if (loader == null)
             loader = AccessController.doPrivileged(
                 J2DoPrivHelper.getContextClassLoaderAction());

         ConfigurationProvider provider = null;
         StringBuilder errs = null;
         String type = (globals) ? "globals" : "defaults";
         Throwable err = null;
         // most specific to least
         for (int i = _derivations.length - 1; i >= 0; i--) {
             try {
                 provider = (globals) ? _derivations[i].loadGlobals(loader)
                     : _derivations[i].loadDefaults(loader);
                 if (provider != null)
                    return provider;
             } catch (Throwable t) {
                 err = t;
                 errs = (errs == null) ? new StringBuilder() : errs.append("\n");
                 errs.append(_derivations[i].getClass().getName() + ":" + t);
             }
         }
         reportErrors(errs, type, err);
         return null;
     }

     /**
      * Thrown proper exception for given errors.
      */
     private static void reportErrors(StringBuilder errs, String resource,
         Throwable nested) {
         if (errs == null)
             return;
         MissingResourceException ex = new MissingResourceException(errs.toString(),
                 ProductDerivations.class.getName(), resource);
         ex.initCause(nested);
         throw ex;
     }

     /**
      * Return a List<String> of all the fully-qualified anchors specified in
      * <code>propertiesLocation</code>. The return values must be used in
      * conjunction with <code>propertiesLocation</code>. If there are no
      * product derivations or if no product derivations could find anchors,
      * this returns an empty list.
      *
      * @since 1.1.0
      */
     public static List<String> getFullyQualifiedAnchorsInPropertiesLocation(
         final String propertiesLocation) {
         List<String> fqAnchors = new ArrayList<>();
         StringBuilder errs = null;
         Throwable err = null;
         for (int i = _derivations.length - 1; i >= 0; i--) {
             try {
                 if (propertiesLocation == null) {
                     String loc = _derivations[i].getDefaultResourceLocation();
                     addAll(fqAnchors, loc,
                         _derivations[i].getAnchorsInResource(loc));
                     continue;
                 }

                 File f = new File(propertiesLocation);
                 if ((Boolean) J2DoPrivHelper.isFileAction(f).run()) {
                     addAll(fqAnchors, propertiesLocation,
                         _derivations[i].getAnchorsInFile(f));
                 } else {
                     f = new File("META-INF" + File.separatorChar
                         + propertiesLocation);
                     if ((Boolean) J2DoPrivHelper.isFileAction(f).run()) {
                         addAll(fqAnchors, propertiesLocation,
                             _derivations[i].getAnchorsInFile(f));
                     } else {
                         addAll(fqAnchors, propertiesLocation,
                             _derivations[i].getAnchorsInResource(
                                 propertiesLocation));
                     }
                 }
             } catch (Throwable t) {
                 err = t;
                 errs = (errs == null) ? new StringBuilder() : errs.append("\n");
                 errs.append(_derivations[i].getClass().getName() + ":" + t);
             }
         }
         reportErrors(errs, propertiesLocation, err);
         return fqAnchors;
     }

     private static void addAll(Collection collection, String base,
         Collection newMembers) {
         if (newMembers == null || collection == null)
             return;
         for (Object newMember : newMembers) {
             String fqLoc = base + "#" + newMember;
             if (!collection.contains(fqLoc))
                 collection.add(fqLoc);
         }
     }


     public static Set<String> getSupportedQueryHints() {
         Set<String> result = new TreeSet<>();
         // most specific to least
         for (int i = _derivations.length - 1; i >= 0; i--) {
             Set<String> members = _derivations[i].getSupportedQueryHints();
             if (members != null && !members.isEmpty())
                 result.addAll(members);
         }
         return result;
     }


     /**
      * Compare {@link ProductDerivation}s.
      */
     private static class ProductDerivationComparator
         implements Comparator<ProductDerivation> {

         @Override
         public int compare(ProductDerivation o1, ProductDerivation o2) {
             int type1 = o1.getType();
             int type2 = o2.getType();
             if (type1 != type2)
                 return type1 - type2;

             // arbitrary but consistent order
             return o1.getClass().getName().compareTo(o2.getClass().
                 getName());
 		}
 	}

     /**
      * Prints product derivation information.
      */
     public static void main(String[] args) {
         // START - ALLOW PRINT STATEMENTS
         System.err.println(derivationErrorsToString());
         // STOP - ALLOW PRINT STATEMENTS
     }

     /**
      * Return a message about the status of each product derivation.
      */
     private static String derivationErrorsToString() {
         StringBuilder buf = new StringBuilder();
         buf.append("ProductDerivations: ").append(_derivationNames.length);
         for (int i = 0; i < _derivationNames.length; i++) {
             buf.append("\n").append(i + 1).append(". ").
                 append(_derivationNames[i]).append(": ");
             if (_derivationErrors[i] == null)
                 buf.append("OK");
             else
                 buf.append(_derivationErrors[i].toString());
         }
         return buf.toString();
     }
 }
	/*
	* 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.openjpa.lib.conf;

	import java.io.File;
	import java.security.AccessController;
	import java.security.PrivilegedActionException;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.List;
	import java.util.Map;
	import java.util.MissingResourceException;
	import java.util.Set;
	import java.util.TreeSet;

	import org.apache.openjpa.lib.util.J2DoPrivHelper;
	import org.apache.openjpa.lib.util.Localizer;
	import org.apache.openjpa.lib.util.MultiClassLoader;
	import org.apache.openjpa.lib.util.Services;
	import org.apache.openjpa.lib.util.StringUtil;

	/**
	* Utilities for running product derivations.
	*
	* @author Abe White
	* @author Pinaki Poddar
	*/
	public class ProductDerivations {

	private static final Localizer _loc = Localizer.forPackage
	(ProductDerivations.class);

	private static final ProductDerivation[] _derivations;
	private static final String[] _derivationNames;
	private static final Throwable[] _derivationErrors;
	private static String[] _prefixes;
	static {
	MultiClassLoader l = AccessController.doPrivileged(J2DoPrivHelper.newMultiClassLoaderAction());
	l.addClassLoader(0, AccessController
	.doPrivileged(J2DoPrivHelper.getClassLoaderAction(ProductDerivations.class)));
	l.addClassLoader(1, AccessController.doPrivileged(J2DoPrivHelper.getContextClassLoaderAction()));
	_derivationNames = Services.getImplementors(ProductDerivation.class, l);
	_derivationErrors = new Throwable[_derivationNames.length];
	List<ProductDerivation> derivations =
	new ArrayList<>(_derivationNames.length);
	boolean errors = false;
	for (int i = 0; i < _derivationNames.length; i++) {
	try {
	ProductDerivation d = (ProductDerivation)
	AccessController.doPrivileged(
	J2DoPrivHelper.newInstanceAction(
	Class.forName(_derivationNames[i], true, l)));
	d.validate();
	derivations.add(d);
	} catch (Throwable t) {
	if (t instanceof PrivilegedActionException)
	t = ((PrivilegedActionException) t).getException();
	_derivationErrors[i] = t;
	errors = true;
	}
	}

	// must be at least one product derivation to define metadata factories,
	// etc.
	if (derivations.isEmpty()) {
	throw new MissingResourceException(_loc.get
	("no-product-derivations", ProductDerivation.class.getName(),
	derivationErrorsToString()).getMessage(),
	ProductDerivations.class.getName(),"derivations");
	}

	// START - ALLOW PRINT STATEMENTS
	// if some derivations weren't instantiable, warn
	if (errors)
	System.err.println(_loc.get("bad-product-derivations",
	ProductDerivations.class.getName()));
	for (int i = 0; i < _derivationErrors.length; i++) {
	if (_derivationErrors[i] == null)
	continue;
	System.err.println(_derivationNames[i] + ":" +
	_derivationErrors[i]);
	break;
	}
	// STOP - ALLOW PRINT STATEMENTS

	Collections.sort(derivations, new ProductDerivationComparator());
	_derivations =
	derivations.toArray(new ProductDerivation[derivations.size()]);

	List<String> prefixes = new ArrayList<>(2);
	prefixes.add("openjpa");
	for (ProductDerivation derivation : _derivations) {
	String prefix = derivation.getConfigurationPrefix();
	if (prefix != null && !"openjpa".equals(prefix))
	prefixes.add(prefix);
	}
	_prefixes = prefixes.toArray(new String[prefixes.size()]);
	}

	/**
	* Return all the product derivations registered in the current classloader
	*/
	public static ProductDerivation[] getProductDerivations() {
	return _derivations;
	}

	/**
	* Return the recognized prefixes for configuration properties.
	*/
	public static String[] getConfigurationPrefixes() {
	return _prefixes;
	}

	/**
	* Set the configuration prefix array. This is package-visible for
	* testing purposes.
	*
	* @since 0.9.7
	*/
	static void setConfigurationPrefixes(String[] prefixes) {
	_prefixes = prefixes;
	}

	/**
	* Determine the full key name for <code>partialKey</code>, given the
	* registered prefixes and the entries in <code>map</code>. This method
	* computes the appropriate configuration prefix to use by looking
	* through <code>map</code> for a key starting with any of the known
	* configuration prefixes and ending with <code>partialKey</code> and, if a
	* value is found, using the prefix of that key. Otherwise, it uses
	* the first registered prefix.
	*
	* The given <code>partialKey</code> is first tested for containment in the
	* given map without any prefix.
	*
	* @since 0.9.7
	*/
	public static String getConfigurationKey(String partialKey, Map map) {
	String firstKey = (map != null && map.containsKey(partialKey))
	? partialKey : null;
	for (int i = 0; map != null && i < _prefixes.length; i++) {
	String fullKey = _prefixes[i] + "." + partialKey;
	if (map.containsKey(fullKey)) {
	if (firstKey == null)
	firstKey = fullKey;
	else {
	// if we've already found a property with a previous
	// prefix, then this is a collision.
	throw new IllegalStateException(_loc.get(
	"dup-with-different-prefixes", firstKey, fullKey)
	.getMessage());
	}
	}
	}

	if (firstKey == null)
	return _prefixes[0] + "." + partialKey;
	else
	return firstKey;
	}

	/**
	* Apply {@link ProductDerivation#beforeConfigurationConstruct} callbacks
	* to the the given instance. Exceptions other than fatal
	* {@link BootstrapException} are swallowed.
	*/
	public static void beforeConfigurationConstruct(ConfigurationProvider cp) {
	for (ProductDerivation derivation : _derivations) {
	try {
	derivation.beforeConfigurationConstruct(cp);
	}
	catch (BootstrapException be) {
	if (be.isFatal())
	throw be;
	}
	catch (Exception e) {
	// can't log; no configuration yet
	e.printStackTrace();
	}
	}
	}

	/**
	* Apply {@link ProductDerivation#beforeConfigurationLoad} callbacks
	* to the the given instance. Exceptions other than fatal
	* {@link BootstrapException} are swallowed.
	*/
	public static void beforeConfigurationLoad(Configuration conf) {
	for (ProductDerivation derivation : _derivations) {
	try {
	derivation.beforeConfigurationLoad(conf);
	}
	catch (BootstrapException be) {
	if (be.isFatal())
	throw be;
	}
	catch (Exception e) {
	// logging not configured yet
	e.printStackTrace();
	}
	}
	}

	/**
	* Apply {@link ProductDerivation#afterSpecificationSet} callbacks
	* to the the given instance. Exceptions other than fatal
	* {@link BootstrapException} are swallowed.
	*/
	public static void afterSpecificationSet(Configuration conf) {
	for (ProductDerivation derivation : _derivations) {
	try {
	derivation.afterSpecificationSet(conf);
	}
	catch (BootstrapException be) {
	if (be.isFatal())
	throw be;
	}
	catch (Exception e) {
	// logging not configured yet
	e.printStackTrace();
	}
	}
	}

	/**
	* Called as the first step of a Configuration's close() method.
	* Exceptions are swallowed.
	*
	* @since 0.9.7
	*/
	public static void beforeClose(Configuration conf) {
	for (ProductDerivation derivation : _derivations) {
	try {
	derivation.beforeConfigurationClose(conf);
	}
	catch (Exception e) {
	conf.getConfigurationLog().warn(_loc.get("before-close-ex"), e);
	}
	}
	}

	/**
	* Load the given given resource, or return false if it is not a resource
	* this provider understands. The given class loader may be null.
	*
	* @param anchor optional named anchor within a multiple-configuration
	* resource
	*/
	public static ConfigurationProvider load(String resource, String anchor,
	ClassLoader loader) {
	if (StringUtil.isEmpty(resource))
	return null;
	if (loader == null)
	loader = AccessController.doPrivileged(
	J2DoPrivHelper.getContextClassLoaderAction());
	ConfigurationProvider provider = null;
	StringBuilder errs = null;
	// most specific to least
	Throwable err = null;
	for (int i = _derivations.length - 1; i >= 0; i--) {
	try {
	provider = _derivations[i].load(resource, anchor, loader);
	if (provider != null)
	return provider;
	} catch (Throwable t) {
	err = t;
	errs = (errs == null) ? new StringBuilder() : errs.append("\n");
	errs.append(_derivations[i].getClass().getName() + ":" + t);
	}
	}
	reportErrors(errs, resource, err);
	String rsrc = resource + "#" + anchor;
	MissingResourceException ex = new MissingResourceException(rsrc,
	ProductDerivations.class.getName(), rsrc);
	ex.initCause(err);
	throw ex;
	}

	/**
	* Load given file, or return false if it is not a file this provider
	* understands.
	*
	* @param anchor optional named anchor within a multiple-configuration file
	*/
	public static ConfigurationProvider load(File file, String anchor,
	ClassLoader loader) {
	if (file == null)
	return null;
	if (loader == null)
	loader = AccessController.doPrivileged(
	J2DoPrivHelper.getContextClassLoaderAction());
	ConfigurationProvider provider = null;
	StringBuilder errs = null;
	Throwable err = null;
	// most specific to least
	for (int i = _derivations.length - 1; i >= 0; i--) {
	try {
	provider = _derivations[i].load(file, anchor);
	if (provider != null)
	return provider;
	} catch (Throwable t) {
	err = t;
	errs = (errs == null) ? new StringBuilder() : errs.append("\n");
	errs.append(_derivations[i].getClass().getName() + ":" + t);
	}
	}
	String aPath = AccessController.doPrivileged(
	J2DoPrivHelper.getAbsolutePathAction(file));
	reportErrors(errs, aPath, err);
	String rsrc = aPath + "#" + anchor;
	MissingResourceException ex = new MissingResourceException(rsrc,
	ProductDerivations.class.getName(), rsrc);
	ex.initCause(err);
	throw ex;
	}

	/**
	* Return a {@link ConfigurationProvider} that has parsed system defaults.
	*/
	public static ConfigurationProvider loadDefaults(ClassLoader loader) {
	return load(loader, false);
	}

	/**
	* Return a {@link ConfigurationProvider} that has parsed system globals.
	*/
	public static ConfigurationProvider loadGlobals(ClassLoader loader) {
	return load(loader, true);
	}

	/**
	* Load a built-in resource location.
	*/
	private static ConfigurationProvider load(ClassLoader loader,
	boolean globals) {
	if (loader == null)
	loader = AccessController.doPrivileged(
	J2DoPrivHelper.getContextClassLoaderAction());

	ConfigurationProvider provider = null;
	StringBuilder errs = null;
	String type = (globals) ? "globals" : "defaults";
	Throwable err = null;
	// most specific to least
	for (int i = _derivations.length - 1; i >= 0; i--) {
	try {
	provider = (globals) ? _derivations[i].loadGlobals(loader)
	: _derivations[i].loadDefaults(loader);
	if (provider != null)
	return provider;
	} catch (Throwable t) {
	err = t;
	errs = (errs == null) ? new StringBuilder() : errs.append("\n");
	errs.append(_derivations[i].getClass().getName() + ":" + t);
	}
	}
	reportErrors(errs, type, err);
	return null;
	}

	/**
	* Thrown proper exception for given errors.
	*/
	private static void reportErrors(StringBuilder errs, String resource,
	Throwable nested) {
	if (errs == null)
	return;
	MissingResourceException ex = new MissingResourceException(errs.toString(),
	ProductDerivations.class.getName(), resource);
	ex.initCause(nested);
	throw ex;
	}

	/**
	* Return a List<String> of all the fully-qualified anchors specified in
	* <code>propertiesLocation</code>. The return values must be used in
	* conjunction with <code>propertiesLocation</code>. If there are no
	* product derivations or if no product derivations could find anchors,
	* this returns an empty list.
	*
	* @since 1.1.0
	*/
	public static List<String> getFullyQualifiedAnchorsInPropertiesLocation(
	final String propertiesLocation) {
	List<String> fqAnchors = new ArrayList<>();
	StringBuilder errs = null;
	Throwable err = null;
	for (int i = _derivations.length - 1; i >= 0; i--) {
	try {
	if (propertiesLocation == null) {
	String loc = _derivations[i].getDefaultResourceLocation();
	addAll(fqAnchors, loc,
	_derivations[i].getAnchorsInResource(loc));
	continue;
	}

	File f = new File(propertiesLocation);
	if ((Boolean) J2DoPrivHelper.isFileAction(f).run()) {
	addAll(fqAnchors, propertiesLocation,
	_derivations[i].getAnchorsInFile(f));
	} else {
	f = new File("META-INF" + File.separatorChar
	+ propertiesLocation);
	if ((Boolean) J2DoPrivHelper.isFileAction(f).run()) {
	addAll(fqAnchors, propertiesLocation,
	_derivations[i].getAnchorsInFile(f));
	} else {
	addAll(fqAnchors, propertiesLocation,
	_derivations[i].getAnchorsInResource(
	propertiesLocation));
	}
	}
	} catch (Throwable t) {
	err = t;
	errs = (errs == null) ? new StringBuilder() : errs.append("\n");
	errs.append(_derivations[i].getClass().getName() + ":" + t);
	}
	}
	reportErrors(errs, propertiesLocation, err);
	return fqAnchors;
	}

	private static void addAll(Collection collection, String base,
	Collection newMembers) {
	if (newMembers == null \|\| collection == null)
	return;
	for (Object newMember : newMembers) {
	String fqLoc = base + "#" + newMember;
	if (!collection.contains(fqLoc))
	collection.add(fqLoc);
	}
	}


	public static Set<String> getSupportedQueryHints() {
	Set<String> result = new TreeSet<>();
	// most specific to least
	for (int i = _derivations.length - 1; i >= 0; i--) {
	Set<String> members = _derivations[i].getSupportedQueryHints();
	if (members != null && !members.isEmpty())
	result.addAll(members);
	}
	return result;
	}


	/**
	* Compare {@link ProductDerivation}s.
	*/
	private static class ProductDerivationComparator
	implements Comparator<ProductDerivation> {

	@Override
	public int compare(ProductDerivation o1, ProductDerivation o2) {
	int type1 = o1.getType();
	int type2 = o2.getType();
	if (type1 != type2)
	return type1 - type2;

	// arbitrary but consistent order
	return o1.getClass().getName().compareTo(o2.getClass().
	getName());
	}
	}

	/**
	* Prints product derivation information.
	*/
	public static void main(String[] args) {
	// START - ALLOW PRINT STATEMENTS
	System.err.println(derivationErrorsToString());
	// STOP - ALLOW PRINT STATEMENTS
	}

	/**
	* Return a message about the status of each product derivation.
	*/
	private static String derivationErrorsToString() {
	StringBuilder buf = new StringBuilder();
	buf.append("ProductDerivations: ").append(_derivationNames.length);
	for (int i = 0; i < _derivationNames.length; i++) {
	buf.append("\n").append(i + 1).append(". ").
	append(_derivationNames[i]).append(": ");
	if (_derivationErrors[i] == null)
	buf.append("OK");
	else
	buf.append(_derivationErrors[i].toString());
	}
	return buf.toString();
	}
	}