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Tools to assist in the reading of configuration/preferences files in
various formats
/*
* 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.commons.configuration2.resolver;
import java.io.IOException;
import java.io.InputStream;
import java.net.FileNameMap;
import java.net.URL;
import java.net.URLConnection;
import java.util.Vector;
import org.apache.commons.configuration2.io.ConfigurationLogger;
import org.apache.commons.configuration2.ex.ConfigurationException;
import org.apache.commons.configuration2.interpol.ConfigurationInterpolator;
import org.apache.commons.configuration2.io.FileLocator;
import org.apache.commons.configuration2.io.FileLocatorUtils;
import org.apache.commons.configuration2.io.FileSystem;
import org.apache.xml.resolver.CatalogException;
import org.apache.xml.resolver.readers.CatalogReader;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
* Thin wrapper around xml commons CatalogResolver to allow list of catalogs
* to be provided.
* @author Commons
* Configuration team
* @since 1.7
*/
public class CatalogResolver implements EntityResolver
{
/**
* Debug everything.
*/
private static final int DEBUG_ALL = 9;
/**
* Normal debug setting.
*/
private static final int DEBUG_NORMAL = 4;
/**
* Debug nothing.
*/
private static final int DEBUG_NONE = 0;
/**
* The CatalogManager
*/
private final CatalogManager manager = new CatalogManager();
/**
* The FileSystem in use.
*/
private FileSystem fs = FileLocatorUtils.DEFAULT_FILE_SYSTEM;
/**
* The CatalogResolver
*/
private org.apache.xml.resolver.tools.CatalogResolver resolver;
/**
* Stores the logger.
*/
private ConfigurationLogger log;
/**
* Constructs the CatalogResolver
*/
public CatalogResolver()
{
manager.setIgnoreMissingProperties(true);
manager.setUseStaticCatalog(false);
manager.setFileSystem(fs);
initLogger(null);
}
/**
* Set the list of catalog file names
*
* @param catalogs The delimited list of catalog files.
*/
public void setCatalogFiles(final String catalogs)
{
manager.setCatalogFiles(catalogs);
}
/**
* Set the FileSystem.
* @param fileSystem The FileSystem.
*/
public void setFileSystem(final FileSystem fileSystem)
{
this.fs = fileSystem;
manager.setFileSystem(fileSystem);
}
/**
* Set the base path.
* @param baseDir The base path String.
*/
public void setBaseDir(final String baseDir)
{
manager.setBaseDir(baseDir);
}
/**
* Set the {@code ConfigurationInterpolator}.
* @param ci the {@code ConfigurationInterpolator}
*/
public void setInterpolator(final ConfigurationInterpolator ci)
{
manager.setInterpolator(ci);
}
/**
* Enables debug logging of xml-commons Catalog processing.
* @param debug True if debugging should be enabled, false otherwise.
*/
public void setDebug(final boolean debug)
{
if (debug)
{
manager.setVerbosity(DEBUG_ALL);
}
else
{
manager.setVerbosity(DEBUG_NONE);
}
}
/**
*
* Implements the {@code resolveEntity} method
* for the SAX interface.
*
* Presented with an optional public identifier and a system
* identifier, this function attempts to locate a mapping in the
* catalogs.
* If such a mapping is found, the resolver attempts to open
* the mapped value as an InputSource and return it. Exceptions are
* ignored and null is returned if the mapped value cannot be opened
* as an input source.
* If no mapping is found (or an error occurs attempting to open
* the mapped value as an input source), null is returned and the system
* will use the specified system identifier as if no entityResolver
* was specified.
*
* @param publicId The public identifier for the entity in question.
* This may be null.
* @param systemId The system identifier for the entity in question.
* XML requires a system identifier on all external entities, so this
* value is always specified.
* @return An InputSource for the mapped identifier, or null.
* @throws SAXException if an error occurs.
*/
@Override
public InputSource resolveEntity(final String publicId, final String systemId)
throws SAXException
{
String resolved = getResolver().getResolvedEntity(publicId, systemId);
if (resolved != null)
{
final String badFilePrefix = "file://";
final String correctFilePrefix = "file:///";
// Java 5 has a bug when constructing file URLS
if (resolved.startsWith(badFilePrefix) && !resolved.startsWith(correctFilePrefix))
{
resolved = correctFilePrefix + resolved.substring(badFilePrefix.length());
}
try
{
final URL url = locate(fs, null, resolved);
if (url == null)
{
throw new ConfigurationException("Could not locate "
+ resolved);
}
final InputStream is = fs.getInputStream(url);
final InputSource iSource = new InputSource(resolved);
iSource.setPublicId(publicId);
iSource.setByteStream(is);
return iSource;
}
catch (final Exception e)
{
log.warn("Failed to create InputSource for " + resolved, e);
return null;
}
}
return null;
}
/**
* Returns the logger used by this configuration object.
*
* @return the logger
*/
public ConfigurationLogger getLogger()
{
return log;
}
/**
* Allows setting the logger to be used by this object. This
* method makes it possible for clients to exactly control logging behavior.
* Per default a logger is set that will ignore all log messages. Derived
* classes that want to enable logging should call this method during their
* initialization with the logger to be used. Passing in null as
* argument disables logging.
*
* @param log the new logger
*/
public void setLogger(final ConfigurationLogger log)
{
initLogger(log);
}
/**
* Initializes the logger. Checks for null parameters.
*
* @param log the new logger
*/
private void initLogger(final ConfigurationLogger log)
{
this.log = (log != null) ? log : ConfigurationLogger.newDummyLogger();
}
private synchronized org.apache.xml.resolver.tools.CatalogResolver getResolver()
{
if (resolver == null)
{
resolver = new org.apache.xml.resolver.tools.CatalogResolver(manager);
}
return resolver;
}
/**
* Helper method for locating a given file. This implementation delegates to
* the corresponding method in {@link FileLocatorUtils}.
*
* @param fs the {@code FileSystem}
* @param basePath the base path
* @param name the file name
* @return the URL pointing to the file
*/
private static URL locate(final FileSystem fs, final String basePath, final String name)
{
final FileLocator locator =
FileLocatorUtils.fileLocator().fileSystem(fs)
.basePath(basePath).fileName(name).create();
return FileLocatorUtils.locate(locator);
}
/**
* Extend the CatalogManager to make the FileSystem and base directory accessible.
*/
public static class CatalogManager extends org.apache.xml.resolver.CatalogManager
{
/** The static catalog used by this manager. */
private static org.apache.xml.resolver.Catalog staticCatalog;
/** The FileSystem */
private FileSystem fs;
/** The base directory */
private String baseDir = System.getProperty("user.dir");
/** The object for handling interpolation. */
private ConfigurationInterpolator interpolator;
/**
* Set the FileSystem
* @param fileSystem The FileSystem in use.
*/
public void setFileSystem(final FileSystem fileSystem)
{
this.fs = fileSystem;
}
/**
* Retrieve the FileSystem.
* @return The FileSystem.
*/
public FileSystem getFileSystem()
{
return this.fs;
}
/**
* Set the base directory.
* @param baseDir The base directory.
*/
public void setBaseDir(final String baseDir)
{
if (baseDir != null)
{
this.baseDir = baseDir;
}
}
/**
* Return the base directory.
* @return The base directory.
*/
public String getBaseDir()
{
return this.baseDir;
}
public void setInterpolator(final ConfigurationInterpolator ci)
{
interpolator = ci;
}
public ConfigurationInterpolator getInterpolator()
{
return interpolator;
}
/**
* Get a new catalog instance. This method is only overridden because xml-resolver
* might be in a parent ClassLoader and will be incapable of loading our Catalog
* implementation.
*
* This method always returns a new instance of the underlying catalog class.
* @return the Catalog.
*/
@Override
public org.apache.xml.resolver.Catalog getPrivateCatalog()
{
org.apache.xml.resolver.Catalog catalog = staticCatalog;
if (catalog == null || !getUseStaticCatalog())
{
try
{
catalog = new Catalog();
catalog.setCatalogManager(this);
catalog.setupReaders();
catalog.loadSystemCatalogs();
}
catch (final Exception ex)
{
ex.printStackTrace();
}
if (getUseStaticCatalog())
{
staticCatalog = catalog;
}
}
return catalog;
}
/**
* Get a catalog instance.
*
* If this manager uses static catalogs, the same static catalog will
* always be returned. Otherwise a new catalog will be returned.
* @return The Catalog.
*/
@Override
public org.apache.xml.resolver.Catalog getCatalog()
{
return getPrivateCatalog();
}
}
/**
* Overrides the Catalog implementation to use the underlying FileSystem.
*/
public static class Catalog extends org.apache.xml.resolver.Catalog
{
/** The FileSystem */
private FileSystem fs;
/** FileNameMap to determine the mime type */
private final FileNameMap fileNameMap = URLConnection.getFileNameMap();
/**
* Load the catalogs.
* @throws IOException if an error occurs.
*/
@Override
public void loadSystemCatalogs() throws IOException
{
fs = ((CatalogManager) catalogManager).getFileSystem();
final String base = ((CatalogManager) catalogManager).getBaseDir();
// This is safe because the catalog manager returns a vector of strings.
@SuppressWarnings("unchecked")
final
Vector catalogs = catalogManager.getCatalogFiles();
if (catalogs != null)
{
for (int count = 0; count < catalogs.size(); count++)
{
final String fileName = catalogs.elementAt(count);
URL url = null;
InputStream is = null;
try
{
url = locate(fs, base, fileName);
if (url != null)
{
is = fs.getInputStream(url);
}
}
catch (final ConfigurationException ce)
{
final String name = url.toString();
// Ignore the exception.
catalogManager.debug.message(DEBUG_ALL,
"Unable to get input stream for " + name + ". " + ce.getMessage());
}
if (is != null)
{
final String mimeType = fileNameMap.getContentTypeFor(fileName);
try
{
if (mimeType != null)
{
parseCatalog(mimeType, is);
continue;
}
}
catch (final Exception ex)
{
// Ignore the exception.
catalogManager.debug.message(DEBUG_ALL,
"Exception caught parsing input stream for " + fileName + ". "
+ ex.getMessage());
}
finally
{
is.close();
}
}
parseCatalog(base, fileName);
}
}
}
/**
* Parse the specified catalog file.
* @param baseDir The base directory, if not included in the file name.
* @param fileName The catalog file. May be a full URI String.
* @throws IOException If an error occurs.
*/
public void parseCatalog(final String baseDir, final String fileName) throws IOException
{
base = locate(fs, baseDir, fileName);
catalogCwd = base;
default_override = catalogManager.getPreferPublic();
catalogManager.debug.message(DEBUG_NORMAL, "Parse catalog: " + fileName);
boolean parsed = false;
for (int count = 0; !parsed && count < readerArr.size(); count++)
{
final CatalogReader reader = (CatalogReader) readerArr.get(count);
InputStream inStream;
try
{
inStream = fs.getInputStream(base);
}
catch (final Exception ex)
{
catalogManager.debug.message(DEBUG_NORMAL, "Unable to access " + base
+ ex.getMessage());
break;
}
try
{
reader.readCatalog(this, inStream);
parsed = true;
}
catch (final CatalogException ce)
{
catalogManager.debug.message(DEBUG_NORMAL, "Parse failed for " + fileName
+ ce.getMessage());
if (ce.getExceptionType() == CatalogException.PARSE_FAILED)
{
break;
}
// try again!
continue;
}
finally
{
try
{
inStream.close();
}
catch (final IOException ioe)
{
// Ignore the exception.
inStream = null;
}
}
}
if (parsed)
{
parsePendingCatalogs();
}
}
/**
* Perform character normalization on a URI reference.
*
* @param uriref The URI reference
* @return The normalized URI reference.
*/
@Override
protected String normalizeURI(final String uriref)
{
final ConfigurationInterpolator ci = ((CatalogManager) catalogManager).getInterpolator();
final String resolved = ci != null ? String.valueOf(ci.interpolate(uriref)) : uriref;
return super.normalizeURI(resolved);
}
}
}