org.nlab.xml.stream.XmlStreamSpec Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of xml-stream-css Show documentation
Stream Xml using StAX and Css matcher
There is a newer version: 2.0.0
package org.nlab.xml.stream;

import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Spliterator;
import java.util.concurrent.Callable;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import org.apache.commons.lang3.Validate;
import org.jooq.lambda.fi.util.function.CheckedSupplier;
import org.nlab.exception.UncheckedExecutionException;
import org.nlab.util.IoCloser;
import org.nlab.xml.stream.consumer.XmlConsumer;
import org.nlab.xml.stream.context.StreamContext;
import org.nlab.xml.stream.factory.StaxCachedFactory;
import org.nlab.xml.stream.reader.PartialXmlStreamReaderSpliterator;
import org.nlab.xml.stream.reader.XmlMatcherStreamReader;
import org.nlab.xml.stream.reader.XmlStreamReaderSpliterator;

import static org.nlab.util.IoCloser.ioCloser;

/**
 * Created by nlabrot on 14/12/15.
 */
public class XmlStreamSpec {

    private final Path path;
    private final InputStream inputStream;
    private final XMLStreamReader reader;
    private final Callable resource;

    private boolean closeOnFinish = false;
    private boolean partial = false;

    public XmlStreamSpec(Path path) {
        this.path = path;
        this.inputStream = null;
        this.reader = null;
        this.resource = null;
    }

    public XmlStreamSpec(InputStream inputStream) {
        this.path = null;
        this.inputStream = inputStream;
        this.reader = null;
        this.resource = null;
    }

    public XmlStreamSpec(XMLStreamReader reader) {
        this.path = null;
        this.inputStream = null;
        this.reader = reader;
        this.resource = null;
    }

    public XmlStreamSpec(Callable resource) {
        this.path = null;
        this.inputStream = null;
        this.reader = null;
        this.resource = resource;
    }

    public XmlStreamSpec hint() {
        return this;
    }

    public XmlStreamSpec closeOnFinish() {
        this.closeOnFinish = true;
        return this;
    }

    public XmlStreamSpec partial() {
        this.partial = true;
        return this;
    }

    public XmlStream stream() throws Exception {

        if (path != null) {
            return createStream(path);
        } else if (inputStream != null) {
            return createStream(inputStream, closeOnFinish);
        } else if (reader != null) {
            return createStream(reader, closeOnFinish);
        } else if (resource != null) {
            return createStream(resource, closeOnFinish);
        }

        return null;
    }

    public XmlStream uncheckedStream() {
        try {
            return stream();
        } catch (Exception e) {
            throw new UncheckedExecutionException(e);
        }
    }

    public CheckedSupplier sstream() {
        return () -> stream();
    }


    public XmlConsumer consumer() throws Exception {
        return new XmlConsumer(stream());
    }

    public XmlConsumer uncheckedConsumer() {
        try {
            return new XmlConsumer(stream());
        } catch (Exception e) {
            throw new UncheckedExecutionException(e);
        }
    }


    public static XmlStreamSpec with(String path) {
        return new XmlStreamSpec(Paths.get(path));
    }

    public static XmlStreamSpec with(Path path) {
        return new XmlStreamSpec(path);
    }

    public static XmlStreamSpec with(InputStream inputStream) {
        return new XmlStreamSpec(inputStream);
    }

    public static XmlStreamSpec with(XMLStreamReader reader) {
        return new XmlStreamSpec(reader).partial();
    }

    public static XmlStreamSpec with(StreamContext streamContext) {
        return new XmlStreamSpec(streamContext.getStreamReader()).partial();
    }


    private XmlStream createStream(Path file) throws XMLStreamException, IOException {
        InputStream inputStream = null;
        try {
            inputStream = new BufferedInputStream(Files.newInputStream(file));
            return createStream(inputStream, true);
        } catch (Exception e) {
            ioCloser().close(inputStream);
            throw e;
        }
    }

    private XmlStream createStream(XMLStreamReader reader, boolean close) {
        try {
            XmlMatcherStreamReader xmlMatcherStreamReader = createOrCastMatcherStreamReader(reader);
            Stream stream = StreamSupport.stream(createXmlStreamReaderSpliterator(xmlMatcherStreamReader), false);

            if (close) {
                stream = stream.onClose(() -> ioCloser().close(reader));
            }

            return new XmlStream(stream, xmlMatcherStreamReader);

        } catch (Exception e) {
            if (close) {
                ioCloser().close(reader);
            }
            throw e;
        }
    }

    private XmlStream createStream(Callable cis, boolean close) throws Exception {
        Validate.notNull(cis);

        InputStream inputStream = null;
        try {
            inputStream = cis.call();
            return createStream(inputStream,close);
        } catch (Exception e) {
            if (close) {
                ioCloser().close(inputStream);
            }
            throw e;
        }
    }


    private XmlStream createStream(InputStream is, boolean close) throws XMLStreamException {
        Validate.notNull(is);

        XMLStreamReader streamReader = null;
        try {
            streamReader = StaxCachedFactory.getInputFactory().createXMLStreamReader(is);

            XmlMatcherStreamReader xmlMatcherStreamReader = createOrCastMatcherStreamReader(streamReader);
            Stream stream = StreamSupport.stream(createXmlStreamReaderSpliterator(xmlMatcherStreamReader), false);

            if (close) {
                stream.onClose(IoCloser.promiseIoCloser(streamReader, is));
            } else {
                stream.onClose(IoCloser.promiseIoCloser(streamReader));
            }

            return new XmlStream(stream, xmlMatcherStreamReader);

        } catch (Exception e) {
            IoCloser ioCloser = ioCloser().close(streamReader);
            if (close) {
                ioCloser.close(is);
            }
            throw e;
        }
    }

    private XmlMatcherStreamReader createOrCastMatcherStreamReader(XMLStreamReader reader) {
        if (reader instanceof XmlMatcherStreamReader) {
            return (XmlMatcherStreamReader) reader;
        } else {
            return new XmlMatcherStreamReader(reader);
        }
    }

    private Spliterator createXmlStreamReaderSpliterator(XmlMatcherStreamReader reader) {
        if (partial) {
            return new PartialXmlStreamReaderSpliterator(reader);
        } else {
            return new XmlStreamReaderSpliterator(reader);
        }
    }


}