io.milton.http.LockInfoSaxHandler.java Source code

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Here is the source code for io.milton.http.LockInfoSaxHandler.java

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/*
 * 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 io.milton.http;

import io.milton.http.LockInfo.LockDepth;
import java.util.Stack;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

import io.milton.http.LockInfo.LockScope;
import io.milton.http.LockInfo.LockType;
import io.milton.principal.DiscretePrincipal;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.XMLReaderFactory;

public class LockInfoSaxHandler extends DefaultHandler {

    private static final Logger log = LoggerFactory.getLogger(LockInfoSaxHandler.class);

    public static LockInfo parseLockInfo(Request request) throws IOException, FileNotFoundException, SAXException {
        InputStream in = request.getInputStream();

        XMLReader reader = XMLReaderFactory.createXMLReader();
        reader.setFeature("http://xml.org/sax/features/external-parameter-entities", false);

        LockInfoSaxHandler handler = new LockInfoSaxHandler();
        reader.setContentHandler(handler);
        if (log.isDebugEnabled()) {
            ByteArrayOutputStream bout = new ByteArrayOutputStream();
            IOUtils.copy(in, bout);
            byte[] bytes = bout.toByteArray();
            in = new ByteArrayInputStream(bytes);
            log.debug("LockInfo: " + bout.toString());
        }
        reader.parse(new InputSource(in));
        LockInfo info = handler.getInfo();
        info.depth = LockDepth.INFINITY; // todo
        if (info.lockedByUser == null) {
            if (request.getAuthorization() != null) {
                if (request.getAuthorization().getUser() != null) {
                    info.lockedByUser = request.getAuthorization().getUser();
                } else {
                    Object user = request.getAuthorization().getTag();
                    if (user instanceof DiscretePrincipal) {
                        DiscretePrincipal dp = (DiscretePrincipal) user;
                        info.lockedByUser = dp.getPrincipalURL();
                    }
                }

            }
        }
        if (info.lockedByUser == null) {
            log.warn("resource is being locked with a null user. This won't really be locked at all...");
        }
        return info;
    }

    private final LockInfo info = new LockInfo();
    private StringBuilder owner;
    private final Stack<String> elementPath = new Stack<String>();

    @Override
    public void startElement(String uri, String localName, String name, Attributes attributes) throws SAXException {
        elementPath.push(localName);
        if (localName.equals("owner")) {
            owner = new StringBuilder();
        }
        super.startElement(uri, localName, name, attributes);
    }

    @Override
    public void characters(char[] ch, int start, int length) throws SAXException {
        if (owner != null) {
            owner.append(ch, start, length);
        }
    }

    @Override
    public void endElement(String uri, String localName, String name) throws SAXException {
        elementPath.pop();
        if (localName.equals("owner")) {
            getInfo().lockedByUser = owner.toString();
        }
        if (elementPath.size() > 1) {
            if (elementPath.get(1).equals("lockscope")) {
                if (localName.equals("exclusive")) {
                    getInfo().scope = LockScope.EXCLUSIVE;
                } else if (localName.equals("shared")) {
                    getInfo().scope = LockScope.SHARED;
                } else {
                    getInfo().scope = LockScope.NONE;
                }
            } else if (elementPath.get(1).equals("locktype")) {
                if (localName.equals("read")) {
                    getInfo().type = LockType.READ;
                } else if (localName.equals("write")) {
                    getInfo().type = LockType.WRITE;
                } else {
                    getInfo().type = LockType.WRITE;
                }
            }

        }
        super.endElement(uri, localName, name);
    }

    public LockInfo getInfo() {
        return info;
    }
}