/**
* '$RCSfile$'
* Purpose: A Class that implements org.xml.sax.EntityResolver interface
* for resolving external entities
* Copyright: 2000 Regents of the University of California and the
* National Center for Ecological Analysis and Synthesis
* Authors: Jivka Bojilova, Matt Jones
*
* '$Author$'
* '$Date$'
* '$Revision$'
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package edu.ucsb.nceas.metacat;
import org.apache.log4j.Logger;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import edu.ucsb.nceas.metacat.accesscontrol.AccessControlList;
import edu.ucsb.nceas.metacat.database.DBConnection;
import edu.ucsb.nceas.metacat.database.DBConnectionPool;
import edu.ucsb.nceas.metacat.util.SystemUtil;
import edu.ucsb.nceas.utilities.PropertyNotFoundException;
import java.sql.*;
import java.io.File;
import java.io.Reader;
import java.io.BufferedReader;
import java.io.BufferedInputStream;
import java.io.FileWriter;
import java.io.BufferedWriter;
import java.io.InputStream;
import java.io.IOException;
import java.net.URL;
import java.net.MalformedURLException;
/**
* A database aware Class implementing EntityResolver interface for the SAX
* parser to call when processing the XML stream and intercepting any
* external entities (including the external DTD subset and external
* parameter entities, if any) before including them.
*/
public class DBEntityResolver implements EntityResolver
{
private DBConnection connection = null;
private DefaultHandler handler = null;
private String docname = null;
private String doctype = null;
private String systemid = null;
private Reader dtdtext = null;
private static Logger logMetacat = Logger.getLogger(DBEntityResolver.class);
/**
* Construct an instance of the DBEntityResolver class
*
* @param conn the JDBC connection to which information is written
*/
public DBEntityResolver(DBConnection conn)
{
this.connection= conn;
}
/**
* Construct an instance of the DBEntityResolver class
*
* @param conn the JDBC connection to which information is written
* @param handler the SAX handler to determine parsing context
* @param dtd Reader of new dtd to be uploaded on server's file system
*/
public DBEntityResolver(DBConnection conn, DefaultHandler handler, Reader dtd)
{
this.connection = conn;
this.handler = handler;
this.dtdtext = dtd;
}
/**
* The Parser call this method before opening any external entity
* except the top-level document entity (including the external DTD subset,
* external entities referenced within the DTD, and external entities
* referenced within the document element)
*/
public InputSource resolveEntity (String publicId, String systemId)
throws SAXException
{
InputSource dtdSource= null;
logMetacat.debug("DBEntityResolver.resolveEntity - in resolveEntity "+" the public id is "+publicId+" and systemId is "+systemId);
String dbSystemID;
String doctype = null;
// Won't have a handler under all cases
if ( handler != null ) {
String message = "Metacat can't determine the public id or the name of the root element of the document, so the validation can't be applied and the document is rejected";
logMetacat.debug("DBEntityResolver.resolveEntity - the handler class is "+handler.getClass().getCanonicalName());
if ( handler instanceof DBSAXHandler ) {
DBSAXHandler dhandler = null;
dhandler = (DBSAXHandler)handler;
if ( dhandler.processingDTD() ) {
logMetacat.debug("DBEntityResolver.resolveEntity - in the branch of the handler class is DBSAXHandler");
// public ID is doctype
if (publicId != null) {
doctype = publicId;
logMetacat.debug("DBEntityResolver.resolveEntity - the publicId is not null, so the publicId is the doctype. The doctype is: "
+ doctype);
// assume public ID (doctype) is docname
} else {
doctype = dhandler.getDocname();
logMetacat.debug("DBEntityResolver.resolveEntity - the publicId is null and we treat the doc name(the root element name) as the doc type. The doctype is: "
+ doctype);
}
if(doctype == null || doctype.trim().equals("")) {
//we can't determine the public id or the name of the root element in for this dtd defined xml document
logMetacat.error("DBEntityResolver.resolveEntity - "+message);
throw new SAXException(message);
} else {
logMetacat.debug("DBEntityResolver.resolveEntity - the final doctype for DBSAXHandler "+doctype);
}
}
} else if ( handler instanceof AccessControlList ) {
logMetacat.debug("DBEntityResolver.resolveEntity - in the branch of the handler class is AccessControlList");
AccessControlList ahandler = null;
ahandler = (AccessControlList)handler;
if ( ahandler.processingDTD() ) {
// public ID is doctype
if (publicId != null) {
doctype = publicId;
logMetacat.debug("DBEntityResolver.resolveEntity - the publicId is not null, so the publicId is the doctype. The doctype in AccessControlList is: "
+ doctype);
// assume public ID (doctype) is docname
} else {
doctype = ahandler.getDocname();
logMetacat.debug("DBEntityResolver.resolveEntity - the publicId is null and we treat the doc name(the root element name) as the doc type. The doctype in AccessControlList is: "
+ doctype);
}
if(doctype == null || doctype.trim().equals("")) {
//we can't determine the public id or the name of the root element in for this dtd defined xml document
logMetacat.error("DBEntityResolver.resolveEntity - "+message);
throw new SAXException(message);
} else {
logMetacat.debug("DBEntityResolver.resolveEntity - the final doctype for AccessControList "+doctype);
}
} else {
logMetacat.debug("DBEntityResolver.resolveEntity - the method resolverEntity for the AccessControList class is not processing a dtd");
}
} else {
logMetacat.debug("DBEntityResolver.resolveEntity - in the branch of the other handler class");
}
} else {
logMetacat.debug("DBEntityResolver.resolveEntity - the xml handler is null. So we can't find the doctype.");
}
// get System ID for doctype
if (doctype != null) {
// look at db XML Catalog for System ID
logMetacat.info("DBEntityResolver.resolveEntity - get systemId from doctype: " + doctype);
dbSystemID = getDTDSystemID(doctype);
logMetacat.info("DBEntityResolver.resolveEntity - The Systemid from xml_catalog table is: " + dbSystemID);
if(dbSystemID == null) {
logMetacat.error("DBEntityResolver.resolveEntity - "+"The doctype: "+doctype+" , which was defined by a DTD document, isn't registered in Metacat. Please contact the operator of the Metacat");
throw new SAXException("The doctype: "+doctype+" , which was defined by a DTD document, isn't registered in Metacat. Please contact the operator of the Metacat");
}
// check that it is accessible on our system before getting too far
try {
InputStream in = checkURLConnection(dbSystemID);
dtdSource = new InputSource(in);
} catch (SAXException se) {
se.printStackTrace();
throw se;
// after an upgrade, the dtd will not exist on disk, but it is in xml catalog. The db system id may be pointing
// back at this system Try and download it from the original system id and see if we still have a problem
// checking the URL connection.
/*logMetacat.warn("DBEntityResolver.resolveEntity - Problem when checking URL Connection: " + se.getMessage());
logMetacat.warn("DBEntityResolver.resolveEntity - Probably, dtd for doc type " + doctype + " existed in xml catalog, but not on disk. Uploading from: " + systemId);
InputStream istream = checkURLConnection(systemId);
uploadDTDFromURL(istream, systemId);
try {
Thread.currentThread().sleep(6000);
checkURLConnection(dbSystemID);
} catch (Exception e2) {
logMetacat.error("DBEntityResolver.resolveEntity - still could not find dtd for doc type " + doctype + " at "
+ dbSystemID + " : " + e2.getMessage());
dbSystemID = null;
}*/
}
/*boolean doctypeIsInDB = true;
// no System ID found in db XML Catalog
if (dbSystemID == null) {
doctypeIsInDB = false;
// use the provided System ID
if (systemId != null) {
dbSystemID = systemId;
}
logMetacat.info("DBEntityResolver.resolveEntity - If above Systemid is null, then get "
+ "system id from file: " + dbSystemID);
}
// there are dtd text provided; try to upload on Metacat
if ( dtdtext != null ) {
dbSystemID = uploadDTD(dbSystemID);
}
// open URLConnection to check first
InputStream istream = checkURLConnection(dbSystemID);
// need to register System ID in db XML Catalog if not yet
if ( !doctypeIsInDB ) {
// new DTD from outside URL location; try to upload on Metacat
if ( dtdtext == null ) {
dbSystemID = uploadDTDFromURL(istream, dbSystemID);
}
registerDTD(doctype, dbSystemID);
}
// return a byte-input stream for use
InputSource is = new InputSource(dbSystemID);
// close and open URLConnection again
try {
istream.close();
} catch (IOException e) {
throw new SAXException
("DBEntityResolver.resolveEntity - I/O issue when resolving entity: " + e.getMessage());
}
istream = checkURLConnection(dbSystemID);
is.setByteStream(istream);
return is;*/
} else {
//InputStream istream = checkURLConnection(systemId);
//return null;
}
return dtdSource;
}
/**
* Look at db XML Catalog to get System ID (if any) for @doctype.
* Return null if there are no System ID found for @doctype
*/
private static String getDTDSystemID( String doctype )
throws SAXException
{
String systemid = null;
PreparedStatement pstmt = null;
DBConnection conn = null;
int serialNumber = -1;
ResultSet rs = null;
try {
//check out DBConnection
conn=DBConnectionPool.getDBConnection("DBEntityResolver.getDTDSystemID");
serialNumber=conn.getCheckOutSerialNumber();
String sql = "SELECT system_id FROM xml_catalog " +
"WHERE entry_type = 'DTD' AND public_id = ?";
pstmt = conn.prepareStatement(sql);
pstmt.setString(1, doctype);
pstmt.execute();
rs = pstmt.getResultSet();
boolean tableHasRows = rs.next();
if (tableHasRows) {
systemid = rs.getString(1);
// system id may not have server url on front. Add it if not.
if (!systemid.startsWith("http://")) {
systemid = SystemUtil.getInternalContextURL() + systemid;
}
}
//pstmt.close();
} catch (SQLException e) {
throw new SAXException
("DBEntityResolver.getDTDSystemID - SQL error when getting DTD system ID: " + e.getMessage());
} catch (PropertyNotFoundException pnfe) {
throw new SAXException
("DBEntityResolver.getDTDSystemID - Property error when getting DTD system ID: " + pnfe.getMessage());
}
finally
{
try
{
if(rs != null) {
rs.close();
}
if(pstmt != null) {
pstmt.close();
}
}//try
catch (SQLException sqlE)
{
logMetacat.error("DBEntityResolver.getDTDSystemId - SQL error: " + sqlE.getMessage());
}//catch
finally
{
DBConnectionPool.returnDBConnection(conn, serialNumber);
}//finally
}//finally
// return the selected System ID
return systemid;
}
/**
* Register new DTD identified by @systemId in Metacat XML Catalog
* . make a reference with @systemId for @doctype in Metacat DB
*/
/*private void registerDTD ( String doctype, String systemId )
throws SAXException
{
String existingSystemId = getDTDSystemID(doctype);
if (existingSystemId != null && existingSystemId.equals(systemId)) {
logMetacat.warn("DBEntityResolver.registerDTD - doctype/systemId already registered in DB: " + doctype);
return;
}
//DBConnection conn = null;
//int serialNumber = -1;
PreparedStatement pstmt = null;
// make a reference in db catalog table with @systemId for @doctype
try {
//check out DBConnection
//conn=DBConnectionPool.getDBConnection("DBEntityResolver.registerDTD");
//serialNumber=conn.getCheckOutSerialNumber();
pstmt = connection.prepareStatement(
"INSERT INTO xml_catalog " +
"(entry_type, public_id, system_id) " +
"VALUES ('DTD', ?, ?)");
// Increase usage count
connection.increaseUsageCount(1);
// Bind the values to the query
pstmt.setString(1, doctype);
pstmt.setString(2, systemId);
// Do the insertion
pstmt.execute();
int updateCnt = pstmt.getUpdateCount();
logMetacat.debug("DBEntityReolver.registerDTD - DTDs registered: " + updateCnt);
pstmt.close();
} catch (SQLException e) {
throw new SAXException
("DBEntityResolver.registerDTD - SQL issue when registering DTD: " + e.getMessage());
}
finally
{
try
{
pstmt.close();
}//try
catch (SQLException sqlE)
{
logMetacat.error("DBEntityResolver.registerDTD - SQL error: " + sqlE.getMessage());
}//catch
//DBConnectionPool.returnDBConnection(conn, serialNumber);
}//finally
}*/
/**
* Upload new DTD text identified by
*
* @systemId to Metacat file system
*/
/*private String uploadDTD(String systemId) throws SAXException {
String dtdPath = null;
String dtdURL = null;
try {
dtdPath = SystemUtil.getContextDir() + "/dtd/";
dtdURL = SystemUtil.getContextURL() + "/dtd/";
} catch (PropertyNotFoundException pnfe) {
throw new SAXException("DBEntityResolver.uploadDTD: " + pnfe.getMessage());
}
// get filename from systemId
String filename = systemId;
int slash = Math.max(filename.lastIndexOf('/'), filename.lastIndexOf('\\'));
if (slash > -1) {
filename = filename.substring(slash + 1);
}
// writing dtd text on Metacat file system as filename
try {
// create a buffering character-input stream
// that uses a default-sized input buffer
BufferedReader in = new BufferedReader(dtdtext);
// open file writer to write the input into it
// String dtdPath = "/opt/tomcat/webapps/bojilova/dtd/";
File f = new File(dtdPath, filename);
synchronized (f) {
try {
if (f.exists()) {
throw new IOException("File already exist: "
+ f.getCanonicalFile());
// if ( f.exists() && !f.canWrite() ) {
// throw new IOException("Not writable: " +
// f.getCanonicalFile());
}
} catch (SecurityException se) {
// if a security manager exists,
// its checkRead method is called for f.exist()
// or checkWrite method is called for f.canWrite()
throw se;
}
// create a buffered character-output stream
// that uses a default-sized output buffer
FileWriter fw = new FileWriter(f);
BufferedWriter out = new BufferedWriter(fw);
// read the input and write into the file writer
String inputLine;
while ((inputLine = in.readLine()) != null) {
out.write(inputLine, 0, inputLine.length());
out.newLine(); // instead of out.write('\r\n');
}
// the input and the output streams must be closed
in.close();
out.flush();
out.close();
fw.close();
} // end of synchronized
} catch (MalformedURLException e) {
throw new SAXException("DBEntityResolver.uploadDTD() - Malformed URL when uploading DTD: " + e.getMessage());
} catch (IOException e) {
throw new SAXException("DBEntityResolver.uploadDTD - I/O issue when uploading DTD: " + e.getMessage());
} catch (SecurityException e) {
throw new SAXException("DBEntityResolver.uploadDTD() - Security issue when uploading DTD: " + e.getMessage());
}
// String dtdURL = "http://dev.nceas.ucsb.edu/bojilova/dtd/";
return dtdURL + filename;
}*/
/**
* Upload new DTD located at outside URL to Metacat file system
*/
/*private String uploadDTDFromURL(InputStream istream, String systemId)
throws SAXException {
String dtdPath = null;
String dtdURL = null;
try {
dtdPath = SystemUtil.getContextDir() + "/dtd/";
dtdURL = SystemUtil.getContextURL() + "/dtd/";
} catch (PropertyNotFoundException pnfe) {
throw new SAXException("DBEntityResolver.uploadDTDFromURL - Property issue when uploading DTD from URL: "
+ pnfe.getMessage());
}
// get filename from systemId
String filename = systemId;
int slash = Math.max(filename.lastIndexOf('/'), filename.lastIndexOf('\\'));
if (slash > -1) {
filename = filename.substring(slash + 1);
}
// writing dtd text on Metacat file system as filename
try {
// create a buffering character-input stream
// that uses a default-sized input buffer
BufferedInputStream in = new BufferedInputStream(istream);
// open file writer to write the input into it
//String dtdPath = "/opt/tomcat/webapps/bojilova/dtd/";
File f = new File(dtdPath, filename);
synchronized (f) {
try {
if (f.exists()) {
logMetacat.warn("DBEntityResolver.uploadDTDFromURL - File already exists: " + f.getCanonicalFile());
//return dtdURL + filename;
//throw new IOException("File already exist: "
// + f.getCanonicalFile());
//if ( f.exists() && !f.canWrite() ) {
// throw new IOException("Not writable: " + f.getCanonicalFile());
}
} catch (SecurityException se) {
// if a security manager exists,
// its checkRead method is called for f.exist()
// or checkWrite method is called for f.canWrite()
throw se;
}
// create a buffered character-output stream
// that uses a default-sized output buffer
FileWriter fw = new FileWriter(f);
BufferedWriter out = new BufferedWriter(fw);
// read the input and write into the file writer
int inputByte;
while ((inputByte = in.read()) != -1) {
out.write(inputByte);
//out.newLine(); //instead of out.write('\r\n');
}
// the input and the output streams must be closed
in.close();
out.flush();
out.close();
fw.close();
} // end of synchronized
} catch (MalformedURLException e) {
throw new SAXException("DBEntityResolver.uploadDTDFromURL - Malformed URL when uploading DTD from URL: "
+ e.getMessage());
} catch (IOException e) {
throw new SAXException("DBEntityResolver.uploadDTDFromURL - I/O issue when uploading DTD from URL: "
+ e.getMessage());
} catch (SecurityException e) {
throw new SAXException("DBEntityResolver.uploadDTDFromURL - Security issue when uploading DTD from URL: "
+ e.getMessage());
}
//String dtdURL = "http://dev.nceas.ucsb.edu/bojilova/dtd/";
return dtdURL + filename;
}*/
/**
* Check URL Connection for @systemId, and return an InputStream
* that can be used to read from the systemId URL. The parser ends
* up using this via the InputSource to read the DTD.
*
* @param systemId a URI (in practice URL) to be checked and opened
*/
public static InputStream checkURLConnection(String systemId) throws SAXException {
try {
return (new URL(systemId).openStream());
} catch (MalformedURLException e) {
throw new SAXException("DBEntityResolver.checkURLConnection - Malformed URL when checking URL Connection: "
+ e.getMessage());
} catch (IOException e) {
throw new SAXException("DBEntityResolver.checkURLConnection - I/O issue when checking URL Connection: "
+ e.getMessage());
}
}
}