com.lyncode.xoai.serviceprovider.parsers.ListSetsParser Maven / Gradle / Ivy

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/**
 * Copyright 2012 Lyncode
 *
 * Licensed 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
 *
 *     client://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 com.lyncode.xoai.serviceprovider.parsers;

import static com.lyncode.xml.matchers.QNameMatchers.localPart;
import static com.lyncode.xml.matchers.XmlEventMatchers.aStartElement;
import static com.lyncode.xml.matchers.XmlEventMatchers.anEndElement;
import static com.lyncode.xml.matchers.XmlEventMatchers.elementName;
import static com.lyncode.xml.matchers.XmlEventMatchers.text;
import static com.lyncode.xml.matchers.XmlEventMatchers.theEndOfDocument;
import static com.lyncode.xoai.model.oaipmh.Error.Code.NO_RECORDS_MATCH;
import static com.lyncode.xoai.model.oaipmh.Error.Code.NO_SET_HIERARCHY;
import static org.hamcrest.CoreMatchers.allOf;
import static org.hamcrest.CoreMatchers.equalTo;

import java.util.ArrayList;
import java.util.List;

import javax.xml.namespace.QName;
import javax.xml.stream.events.XMLEvent;

import org.hamcrest.Matcher;

import com.lyncode.xml.XmlReader;
import com.lyncode.xml.exceptions.XmlReaderException;
import com.lyncode.xoai.model.oaipmh.Set;
import com.lyncode.xoai.serviceprovider.exceptions.EncapsulatedKnownException;
import com.lyncode.xoai.serviceprovider.exceptions.InvalidOAIResponse;
import com.lyncode.xoai.serviceprovider.exceptions.NoSetHierarchyException;

public class ListSetsParser {
    private final XmlReader reader;
    private boolean awaitingNextInvocation = false;

    public ListSetsParser(XmlReader reader) {
        this.reader = reader;
    }

    public boolean hasNext () throws XmlReaderException {
        if (!awaitingNextInvocation)
            reader.next(setElement(), errorElement(), resumptionToken(), theEndOfDocument());
        awaitingNextInvocation = true;
        if (reader.current(errorElement())) {
            String code = reader.getAttributeValue(localPart(equalTo("code")));
            if (equalTo(NO_RECORDS_MATCH.code()).matches(code))
                return false;
            else if (equalTo(NO_SET_HIERARCHY.code()).matches(code))
                throw new EncapsulatedKnownException(new NoSetHierarchyException());
            else
                throw new InvalidOAIResponse("OAI responded with code: " + code);
        }
        return reader.current(setElement());
    }

    private Matcher resumptionToken() {
        return allOf(aStartElement(), elementName(localPart(equalTo("resumptionToken"))));
    }

    public Set next() throws XmlReaderException {
        if (!hasNext()) throw new XmlReaderException("No more identifiers available");
        awaitingNextInvocation = false;
        return parseSet();
    }

    @SuppressWarnings("unchecked")
	private Set parseSet() throws XmlReaderException {
        Set set = new Set();
        
        String setName = null;
        String setSpec = null;
        
        while(setName == null || setSpec == null) {
        	reader.next(aStartElement());
            QName elementName = reader.getName();
            reader.next(text());
            String extractedText = reader.getText();
            while(reader.next(anEndElement(),text()).current(text())){
            	extractedText += reader.getText();
            }
            if(elementName.getLocalPart().equals("setName")) {
            	setName = extractedText;
            } else if(elementName.getLocalPart().equals("setSpec")) {
            	setSpec = extractedText;
            }
        }
        set.withName(setName);
        set.withSpec(setSpec);
        return set;
    }


    private Matcher errorElement() {
        return elementName(localPart(equalTo("error")));
    }

    private Matcher setElement() {
        return allOf(aStartElement(), elementName(localPart(equalTo("set"))));
    }
    private Matcher endSetElement() {
        return allOf(anEndElement(), elementName(localPart(equalTo("set"))));
    }

	/**
	 * Parses its xml completely
	 * @return - All sets within the xml
	 * @throws XmlReaderException
	 */
	public List parse() throws XmlReaderException {
		List sets = new ArrayList();
		while (hasNext())
            sets.add(next());
		return sets;
	}
}