/*
* BioJava development code
*
* This code may be freely distributed and modified under the
* terms of the GNU Lesser General Public Licence. This should
* be distributed with the code. If you do not have a copy,
* see:
*
* http://www.gnu.org/copyleft/lesser.html
*
* Copyright for this code is held jointly by the individual
* authors. These should be listed in @author doc comments.
*
* For more information on the BioJava project and its aims,
* or to join the biojava-l mailing list, visit the home page
* at:
*
* http://www.biojava.org/
*
*/
package org.biojava.nbio.structure;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.biojava.nbio.core.util.InputStreamProvider;
import org.biojava.nbio.structure.StructureIO.StructureFiletype;
import org.biojava.nbio.structure.align.util.AtomCache;
import org.biojava.nbio.structure.io.PDBFileReader;
import org.biojava.nbio.structure.io.mmcif.MMcifParser;
import org.biojava.nbio.structure.io.mmcif.SimpleMMcifConsumer;
import org.biojava.nbio.structure.io.mmcif.SimpleMMcifParser;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Represents a structure loaded from a URL (including a file URL)
*
* A few custom query parameters are supported:
*
* <ul>
* <li><tt>format=[pdb|cif]</tt> Specify the file format (will otherwise be
* guessed from the extension)
* <li><tt>pdbId=[String]</tt> Specify the PDB ID (also guessed from the filename)
* <li><tt>chainID=[String]</tt> A single chain from the structure
* <li><tt>residues=[String]</tt> Residue ranges, in a form understood by
* {@link SubstructureIdentifier}
* </ul>
* @author Spencer Bliven
*
*/
public class URLIdentifier implements StructureIdentifier {
private static final Logger logger = LoggerFactory.getLogger(URLIdentifier.class);
// Used for guessing the PDB ID from the filename
private static final Pattern PDBID_REGEX = Pattern.compile("^([0-9][a-z0-9]{3})([._-]|\\s).*",Pattern.CASE_INSENSITIVE);
/** URL parameter specifying the file format (PDB or CIF) */
public static final String FORMAT_PARAM = "format";
/** URL parameter specifying the PDB ID */
public static final String PDBID_PARAM = "pdbid";
/** URL parameter specifying a single chain to include; overridden by residues */
//TODO: should this get renamed to chainname or asymid?
public static final String CHAINID_PARAM = "chainid";
/** URL parameter specifying residue ranges to include, e.g. <tt>residues=A:1-70</tt>
* @see SubstructureIdentifier
*/
public static final String RESIDUES_PARAM = "residues";
final private URL url;
public URLIdentifier(URL url) {
this.url = url;
}
public URLIdentifier(String url) throws MalformedURLException {
this(new URL(url));
}
public URL getURL() {
return url;
}
@Override
public String getIdentifier() {
return url.toString();
}
/**
* @return A SubstructureIdentifier without ranges (e.g. including all residues)
*/
@Override
public SubstructureIdentifier toCanonical() {
String pdbId = null;
List<ResidueRange> ranges = Collections.emptyList();
try {
Map<String, String> params = parseQuery(url);
if(params.containsKey(PDBID_PARAM)) {
pdbId = params.get(PDBID_PARAM);
}
if(params.containsKey(RESIDUES_PARAM)) {
ranges = ResidueRange.parseMultiple(params.get(RESIDUES_PARAM));
} else if(params.containsKey(CHAINID_PARAM)) {
ranges = Arrays.asList(new ResidueRange(params.get(CHAINID_PARAM),(ResidueNumber)null,(ResidueNumber)null));
}
} catch (UnsupportedEncodingException e) {
logger.error("Unable to decode URL "+url,e);
}
if(pdbId == null) {
String path = url.getPath();
pdbId = guessPDBID(path.substring(path.lastIndexOf("/")+1));
}
return new SubstructureIdentifier(pdbId, ranges);
}
@Override
public Structure reduce(Structure input) throws StructureException {
return toCanonical().reduce(input);
}
/**
* Load the structure from the URL
* @return null
*/
@Override
public Structure loadStructure(AtomCache cache) throws StructureException,
IOException {
StructureFiletype format = StructureFiletype.UNKNOWN;
// Use user-specified format
try {
Map<String, String> params = parseQuery(url);
if(params.containsKey(FORMAT_PARAM)) {
String formatStr = params.get(FORMAT_PARAM);
format = StructureIO.guessFiletype("."+formatStr);
}
} catch (UnsupportedEncodingException e) {
logger.error("Unable to decode URL "+url,e);
}
// Guess format from extension
if(format == StructureFiletype.UNKNOWN) {
format = StructureIO.guessFiletype(url.getPath());
}
switch(format) {
case CIF:
// need to do mmcif parsing!
InputStreamProvider prov = new InputStreamProvider();
InputStream inStream = prov.getInputStream(url);
MMcifParser parser = new SimpleMMcifParser();
SimpleMMcifConsumer consumer = new SimpleMMcifConsumer();
consumer.setFileParsingParameters(cache.getFileParsingParams());
parser.addMMcifConsumer(consumer);
try {
parser.parse(new BufferedReader(new InputStreamReader(inStream)));
} catch (IOException e){
e.printStackTrace();
}
// now get the protein structure.
return consumer.getStructure();
default:
case PDB:
// pdb file based parsing
PDBFileReader reader = new PDBFileReader(cache.getPath());
reader.setFetchBehavior(cache.getFetchBehavior());
reader.setObsoleteBehavior(cache.getObsoleteBehavior());
reader.setFileParsingParameters(cache.getFileParsingParams());
return reader.getStructure(url);
}
}
/**
* Recognizes PDB IDs that occur at the beginning of name followed by some
* delimiter.
* @param name Input filename
* @return A 4-character id-like string, or null if none is found
*/
public static String guessPDBID(String name) {
Matcher match = PDBID_REGEX.matcher(name);
if(match.matches()) {
return match.group(1).toUpperCase();
} else {
// Give up if doesn't match
return null;
}
}
/**
* Parses URL parameters into a map. Keys are stored lower-case.
*
* @param url
* @return
* @throws UnsupportedEncodingException
*/
private static Map<String,String> parseQuery(URL url) throws UnsupportedEncodingException {
Map<String,String> params = new LinkedHashMap<String, String>();
String query = url.getQuery();
if( query == null || query.isEmpty()) {
// empty query
return params;
}
String[] pairs = url.getQuery().split("&");
for(String pair: pairs) {
int i = pair.indexOf("=");
String key = pair;
if(i > 0) {
key = URLDecoder.decode(pair.substring(0, i), "UTF-8");
}
String value = null;
if(i > 0 && pair.length() > i+1) {
value = URLDecoder.decode(pair.substring(i+1), "UTF-8");
}
// note that this uses the last instance if a parameter is specified multiple times
params.put(key.toLowerCase(), value);
}
return params;
}
}