/* (c) 2014 - 2015 Open Source Geospatial Foundation - all rights reserved
* (c) 2001 - 2013 OpenPlans
* This code is licensed under the GPL 2.0 license, available at the root
* application directory.
*/
package org.geoserver.wfs.xslt.config;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.transform.ErrorListener;
import javax.xml.transform.Source;
import javax.xml.transform.Templates;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamSource;
import org.apache.commons.io.IOUtils;
import org.geoserver.catalog.Catalog;
import org.geoserver.catalog.FeatureTypeInfo;
import org.geoserver.catalog.impl.FeatureTypeInfoImpl;
import org.geoserver.config.GeoServerDataDirectory;
import org.geoserver.config.util.SecureXStream;
import org.geoserver.platform.resource.Paths;
import org.geoserver.platform.resource.Resource;
import org.geoserver.platform.resource.Resources;
import org.geoserver.util.Filter;
import org.geoserver.wfs.WFSException;
import org.geotools.util.logging.Logging;
import com.thoughtworks.xstream.XStream;
/**
* Manages access to the XLST transformation definitions
*
* @author Andrea Aime - GeoSolutions
*/
public class TransformRepository {
static final Logger LOGGER = Logging.getLogger(TransformRepository.class);
static final Filter<Resource> CONFIG_NAME_FILTER = new Resources.ExtensionFilter("XML");
XStream xs;
GeoServerDataDirectory dataDir;
/**
* Caches the {@link TransformInfo} objects so that we don't have to load them from disk all the time
*/
FileItemCache<TransformInfo> infoCache = new FileItemCache<TransformInfo>(100) {
@Override
protected TransformInfo loadItem(Resource file) throws IOException {
if(!Resources.exists(file)) {
return null;
}
InputStream fis = null;
try {
fis = file.in();
TransformInfo info = (TransformInfo) xs.fromXML(fis);
info.setName(getTransformName(file));
return info;
} finally {
IOUtils.closeQuietly(fis);
}
}
};
/**
* Caches the XSLT Templates to avoid parsing the XSLT over and over (Templates is thread safe,
* {@link Transformer} is not.
*/
FileItemCache<Templates> transformCache = new FileItemCache<Templates>(100) {
@Override
protected Templates loadItem(Resource file) throws IOException {
// do not trust StreamSource to do the file closing, reports on the net
// suggest it might not
try (InputStream fis = file.in()) {
Source xslSource = new StreamSource(fis);
TransformerFactory tf = TransformerFactory.newInstance( );
final List<TransformerException> errors = new ArrayList<TransformerException>();
tf.setErrorListener(new ErrorListener() {
@Override
public void warning(TransformerException e) throws TransformerException {
LOGGER.log(Level.WARNING, "Found warning while loading XSLT template", e);
}
@Override
public void fatalError(TransformerException e) throws TransformerException {
errors.add(e);
}
@Override
public void error(TransformerException e) throws TransformerException {
errors.add(e);
}
});
Templates template = tf.newTemplates(xslSource);
if(errors.size() > 0) {
StringBuilder sb = new StringBuilder("Errors found in the template");
for (TransformerException e : errors) {
sb.append("\n").append(e.getMessageAndLocation());
}
throw new IOException(sb.toString());
}
return template;
} catch(TransformerException e) {
throw new IOException("Error found in the template: " + e.getMessageAndLocation());
}
}
};
public TransformRepository(GeoServerDataDirectory dataDir, Catalog catalog) {
this.dataDir = dataDir;
initXStream(catalog);
}
/**
* Sets up xstream to get nice xml output
*
* @param catalog
*/
private void initXStream(Catalog catalog) {
xs = new SecureXStream();
xs.allowTypes(new Class[] { TransformInfo.class });
xs.omitField(TransformInfo.class, "name");
xs.alias("transform", TransformInfo.class);
xs.registerLocalConverter(TransformInfo.class, "featureType", new ReferenceConverter(
FeatureTypeInfo.class, catalog));
xs.addDefaultImplementation(FeatureTypeInfoImpl.class, FeatureTypeInfo.class);
}
/**
* The transform name is the same as the config file, minus the extension
*
* @param file
*
*/
protected String getTransformName(Resource file) {
String name = file.name();
int idx = name.indexOf(".");
if (idx > 0) {
return name.substring(0, idx);
} else {
return name;
}
}
/**
* Returns all the transform (either global or feature type specific)
*
*
*/
public List<TransformInfo> getAllTransforms() throws IOException {
Resource root = dataDir.get(Paths.path("wfs", "transform"));
List<TransformInfo> result = new ArrayList<TransformInfo>();
for (Resource f : Resources.list(root, CONFIG_NAME_FILTER)) {
try {
TransformInfo tx = infoCache.getItem(f);
result.add(tx);
} catch (Exception e) {
LOGGER.log(Level.FINE,
"Failed to load configuration from file " + f.path(), e);
}
}
return result;
}
/**
* Returns all the global transformations (not attached to a particular layer)
*
*
*/
public List<TransformInfo> getGlobalTransforms() throws IOException {
List<TransformInfo> allTransformations = getAllTransforms();
List<TransformInfo> result = new ArrayList<TransformInfo>();
for (TransformInfo ti : allTransformations) {
if (ti.getFeatureType() == null) {
result.add(ti);
}
}
return result;
}
/**
* Returns transformations associated to a specific feature type
*
* @param featureType
*
*/
public List<TransformInfo> getTypeTransforms(FeatureTypeInfo featureType) throws IOException {
List<TransformInfo> allTransformations = getAllTransforms();
List<TransformInfo> result = new ArrayList<TransformInfo>();
for (TransformInfo ti : allTransformations) {
if (ti.getFeatureType() != null
&& ti.getFeatureType().getId().equals(featureType.getId())) {
result.add(ti);
}
}
return result;
}
/**
* Returns a specific transformation by hand
*
* @param name
*
*/
public TransformInfo getTransformInfo(String name) throws IOException {
Resource infoFile = getTransformInfoFile(name);
return infoCache.getItem(infoFile);
}
/**
* Deletes a transformation definition and its associated XSLT file (assuming the
* latter is not shared with other transformations)
*
* @param info
*
* @throws IOException
*/
public boolean removeTransformInfo(TransformInfo info) throws IOException {
Resource infoFile = getTransformInfoFile(info.getName());
boolean result = infoFile.delete();
Resource xsltFile = getTransformFile(info);
infoCache.removeItem(infoFile);
boolean shared = false;
if(Resources.exists(xsltFile)) {
for(TransformInfo ti : getAllTransforms()) {
Resource curr = getTransformFile(ti);
if(curr.equals(xsltFile)) {
shared = true;
break;
}
}
}
if(!shared) {
result = result && xsltFile.delete();
transformCache.removeItem(xsltFile);
}
return result;
}
/**
* Returns the XSLT transformer for a specific {@link TransformInfo}
*
* @param name
*
*/
public Transformer getTransformer(TransformInfo info) throws IOException {
Resource txFile = getTransformFile(info);
Templates templates = transformCache.getItem(txFile);
if(templates != null) {
try {
return templates.newTransformer();
} catch (TransformerConfigurationException e) {
throw new WFSException("Failed to load XSLT transformation " + info.getXslt(), e);
}
} else {
throw new IOException("No XLST found at " + txFile.path());
}
}
/**
* Returns the stylesheet of a transformation. It is the duty of the caller to close the input stream after reading it.
*
* @throws IOException
*/
public InputStream getTransformSheet(TransformInfo info) throws IOException {
Resource txFile = getTransformFile(info);
return txFile.in();
}
/**
* Writes the stylesheet of a transformation. This method will close the provided input stream.
*
* @param info
* @param sheet
* @throws IOException
*/
public void putTransformSheet(TransformInfo info, InputStream sheet) throws IOException {
Resource txFile = getTransformFile(info);
OutputStream fos = null;
try {
fos = txFile.out();
IOUtils.copy(sheet, fos);
} finally {
IOUtils.closeQuietly(sheet);
IOUtils.closeQuietly(fos);
}
}
/**
* Saves/updates the specified transformation
*
* @param transform
* @throws IOException
*/
public void putTransformInfo(TransformInfo transform) throws IOException {
if (transform.getName() == null) {
throw new IllegalArgumentException("Transformation does not have a name set");
}
Resource file = getTransformInfoFile(transform.getName());
try (OutputStream fos = file.out()){
xs.toXML(transform, fos);
}
infoCache.put(transform, file);
}
Resource getTransformInfoFile(String name) throws IOException {
Resource root = dataDir.get(Paths.path("wfs", "transform"));
Resource infoFile = root.get(name + ".xml");
return infoFile;
}
private Resource getTransformFile(TransformInfo info) throws IOException {
String txName = info.getXslt();
Resource root = dataDir.get(Paths.path("wfs", "transform"));
Resource txFile = root.get(txName);
return txFile;
}
}