/*
* 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 org.apache.tinkerpop.gremlin.structure.io.graphml;
import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import java.util.Stack;
/**
* A wrapper for the different {@code XMLStreamWriter} implementations.
*/
final class GraphMLWriterHelper {
private GraphMLWriterHelper() {}
/**
* @author Tijs Rademakers
*/
abstract static class DelegatingXMLStreamWriter implements XMLStreamWriter {
private final XMLStreamWriter writer;
public DelegatingXMLStreamWriter(XMLStreamWriter writer) {
this.writer = writer;
}
public void writeStartElement(String localName) throws XMLStreamException {
writer.writeStartElement(localName);
}
public void writeStartElement(String namespaceURI, String localName) throws XMLStreamException {
writer.writeStartElement(namespaceURI, localName);
}
public void writeStartElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
writer.writeStartElement(prefix, localName, namespaceURI);
}
public void writeEmptyElement(String namespaceURI, String localName) throws XMLStreamException {
writer.writeEmptyElement(namespaceURI, localName);
}
public void writeEmptyElement(String prefix, String localName, String namespaceURI) throws XMLStreamException {
writer.writeEmptyElement(prefix, localName, namespaceURI);
}
public void writeEmptyElement(String localName) throws XMLStreamException {
writer.writeEmptyElement(localName);
}
public void writeEndElement() throws XMLStreamException {
writer.writeEndElement();
}
public void writeEndDocument() throws XMLStreamException {
writer.writeEndDocument();
}
public void close() throws XMLStreamException {
writer.close();
}
public void flush() throws XMLStreamException {
writer.flush();
}
public void writeAttribute(String localName, String value) throws XMLStreamException {
writer.writeAttribute(localName, value);
}
public void writeAttribute(String prefix, String namespaceURI, String localName, String value) throws XMLStreamException {
writer.writeAttribute(prefix, namespaceURI, localName, value);
}
public void writeAttribute(String namespaceURI, String localName, String value) throws XMLStreamException {
writer.writeAttribute(namespaceURI, localName, value);
}
public void writeNamespace(String prefix, String namespaceURI) throws XMLStreamException {
writer.writeNamespace(prefix, namespaceURI);
}
public void writeDefaultNamespace(String namespaceURI) throws XMLStreamException {
writer.writeDefaultNamespace(namespaceURI);
}
public void writeComment(String data) throws XMLStreamException {
writer.writeComment(data);
}
public void writeProcessingInstruction(String target) throws XMLStreamException {
writer.writeProcessingInstruction(target);
}
public void writeProcessingInstruction(String target, String data) throws XMLStreamException {
writer.writeProcessingInstruction(target, data);
}
public void writeCData(String data) throws XMLStreamException {
writer.writeCData(data);
}
public void writeDTD(String dtd) throws XMLStreamException {
writer.writeDTD(dtd);
}
public void writeEntityRef(String name) throws XMLStreamException {
writer.writeEntityRef(name);
}
public void writeStartDocument() throws XMLStreamException {
writer.writeStartDocument();
}
public void writeStartDocument(String version) throws XMLStreamException {
writer.writeStartDocument(version);
}
public void writeStartDocument(String encoding, String version) throws XMLStreamException {
writer.writeStartDocument(encoding, version);
}
public void writeCharacters(String text) throws XMLStreamException {
writer.writeCharacters(text);
}
public void writeCharacters(char[] text, int start, int len) throws XMLStreamException {
writer.writeCharacters(text, start, len);
}
public String getPrefix(String uri) throws XMLStreamException {
return writer.getPrefix(uri);
}
public void setPrefix(String prefix, String uri) throws XMLStreamException {
writer.setPrefix(prefix, uri);
}
public void setDefaultNamespace(String uri) throws XMLStreamException {
writer.setDefaultNamespace(uri);
}
public void setNamespaceContext(NamespaceContext context) throws XMLStreamException {
writer.setNamespaceContext(context);
}
public NamespaceContext getNamespaceContext() {
return writer.getNamespaceContext();
}
public Object getProperty(String name) throws IllegalArgumentException {
return writer.getProperty(name);
}
}
/**
* @author Tijs Rademakers
*/
public static class IndentingXMLStreamWriter extends DelegatingXMLStreamWriter {
private final static Object SEEN_NOTHING = new Object();
private final static Object SEEN_ELEMENT = new Object();
private final static Object SEEN_DATA = new Object();
private Object state = SEEN_NOTHING;
private Stack<Object> stateStack = new Stack<Object>();
private String indentStep = " ";
private int depth = 0;
public IndentingXMLStreamWriter(XMLStreamWriter writer) {
super(writer);
}
/**
* Return the current indent step.
*
* <p>
* Return the current indent step: each start tag will be indented by this
* number of spaces times the number of ancestors that the element has.
* </p>
*
* @return The number of spaces in each indentation step, or 0 or less for no
* indentation.
* @see #setIndentStep(int)
*
* @deprecated Only return the length of the indent string.
*/
public int getIndentStep() {
return indentStep.length();
}
/**
* Set the current indent step.
*
* @param indentStep
* The new indent step (0 or less for no indentation).
* @see #getIndentStep()
*
* @deprecated Should use the version that takes string.
*/
public void setIndentStep(int indentStep) {
StringBuilder s = new StringBuilder();
for (; indentStep > 0; indentStep--)
s.append(' ');
setIndentStep(s.toString());
}
public void setIndentStep(String s) {
this.indentStep = s;
}
private void onStartElement() throws XMLStreamException {
stateStack.push(SEEN_ELEMENT);
state = SEEN_NOTHING;
if (depth > 0) {
super.writeCharacters("\n");
}
doIndent();
depth++;
}
private void onEndElement() throws XMLStreamException {
depth--;
if (state == SEEN_ELEMENT) {
super.writeCharacters("\n");
doIndent();
}
state = stateStack.pop();
}
private void onEmptyElement() throws XMLStreamException {
state = SEEN_ELEMENT;
if (depth > 0) {
super.writeCharacters("\n");
}
doIndent();
}
/**
* Print indentation for the current level.
*
* @exception org.xml.sax.SAXException
* If there is an error writing the indentation characters, or if
* a filter further down the chain raises an exception.
*/
private void doIndent() throws XMLStreamException {
if (depth > 0) {
for (int i = 0; i < depth; i++)
super.writeCharacters(indentStep);
}
}
public void writeStartDocument() throws XMLStreamException {
super.writeStartDocument();
super.writeCharacters("\n");
}
public void writeStartDocument(String version) throws XMLStreamException {
super.writeStartDocument(version);
super.writeCharacters("\n");
}
public void writeStartDocument(String encoding, String version)
throws XMLStreamException {
super.writeStartDocument(encoding, version);
super.writeCharacters("\n");
}
public void writeStartElement(String localName) throws XMLStreamException {
onStartElement();
super.writeStartElement(localName);
}
public void writeStartElement(String namespaceURI, String localName)
throws XMLStreamException {
onStartElement();
super.writeStartElement(namespaceURI, localName);
}
public void writeStartElement(String prefix, String localName,
String namespaceURI) throws XMLStreamException {
onStartElement();
super.writeStartElement(prefix, localName, namespaceURI);
}
public void writeEmptyElement(String namespaceURI, String localName)
throws XMLStreamException {
onEmptyElement();
super.writeEmptyElement(namespaceURI, localName);
}
public void writeEmptyElement(String prefix, String localName,
String namespaceURI) throws XMLStreamException {
onEmptyElement();
super.writeEmptyElement(prefix, localName, namespaceURI);
}
public void writeEmptyElement(String localName) throws XMLStreamException {
onEmptyElement();
super.writeEmptyElement(localName);
}
public void writeEndElement() throws XMLStreamException {
onEndElement();
super.writeEndElement();
}
public void writeCharacters(String text) throws XMLStreamException {
state = SEEN_DATA;
super.writeCharacters(text);
}
public void writeCharacters(char[] text, int start, int len)
throws XMLStreamException {
state = SEEN_DATA;
super.writeCharacters(text, start, len);
}
public void writeCData(String data) throws XMLStreamException {
state = SEEN_DATA;
super.writeCData(data);
}
}
}