Java tutorial
/* * Copyright 2002-2018 the original author or authors. * * 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 * * https://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.springframework.oxm.support; import java.io.IOException; import javax.xml.transform.Source; import javax.xml.transform.sax.SAXResult; import javax.xml.transform.sax.SAXSource; import org.xml.sax.ContentHandler; import org.xml.sax.DTDHandler; import org.xml.sax.EntityResolver; import org.xml.sax.ErrorHandler; import org.xml.sax.InputSource; import org.xml.sax.SAXException; import org.xml.sax.SAXNotRecognizedException; import org.xml.sax.SAXParseException; import org.xml.sax.XMLReader; import org.xml.sax.ext.LexicalHandler; import org.springframework.lang.Nullable; import org.springframework.oxm.Marshaller; import org.springframework.util.Assert; /** * {@link Source} implementation that uses a {@link Marshaller}.Can be constructed with a * {@code Marshaller} and an object to be marshalled. * * <p>Even though {@code MarshallingSource} extends from {@code SAXSource}, calling the methods of * {@code SAXSource} is <strong>not supported</strong>. In general, the only supported operation on this class is * to use the {@code XMLReader} obtained via {@link #getXMLReader()} to parse the input source obtained via {@link * #getInputSource()}. Calling {@link #setXMLReader(XMLReader)} or {@link #setInputSource(InputSource)} will result in * {@code UnsupportedOperationException}s. * * @author Arjen Poutsma * @since 3.0 * @see javax.xml.transform.Transformer */ public class MarshallingSource extends SAXSource { private final Marshaller marshaller; private final Object content; /** * Create a new {@code MarshallingSource} with the given marshaller and content. * @param marshaller the marshaller to use * @param content the object to be marshalled */ public MarshallingSource(Marshaller marshaller, Object content) { super(new MarshallingXMLReader(marshaller, content), new InputSource()); Assert.notNull(marshaller, "'marshaller' must not be null"); Assert.notNull(content, "'content' must not be null"); this.marshaller = marshaller; this.content = content; } /** * Return the {@code Marshaller} used by this {@code MarshallingSource}. */ public Marshaller getMarshaller() { return this.marshaller; } /** * Return the object to be marshalled. */ public Object getContent() { return this.content; } /** * Throws a {@code UnsupportedOperationException}. */ @Override public void setInputSource(InputSource inputSource) { throw new UnsupportedOperationException("setInputSource is not supported"); } /** * Throws a {@code UnsupportedOperationException}. */ @Override public void setXMLReader(XMLReader reader) { throw new UnsupportedOperationException("setXMLReader is not supported"); } private static final class MarshallingXMLReader implements XMLReader { private final Marshaller marshaller; private final Object content; @Nullable private DTDHandler dtdHandler; @Nullable private ContentHandler contentHandler; @Nullable private EntityResolver entityResolver; @Nullable private ErrorHandler errorHandler; @Nullable private LexicalHandler lexicalHandler; private MarshallingXMLReader(Marshaller marshaller, Object content) { Assert.notNull(marshaller, "'marshaller' must not be null"); Assert.notNull(content, "'content' must not be null"); this.marshaller = marshaller; this.content = content; } @Override public void setContentHandler(@Nullable ContentHandler contentHandler) { this.contentHandler = contentHandler; } @Override @Nullable public ContentHandler getContentHandler() { return this.contentHandler; } @Override public void setDTDHandler(@Nullable DTDHandler dtdHandler) { this.dtdHandler = dtdHandler; } @Override @Nullable public DTDHandler getDTDHandler() { return this.dtdHandler; } @Override public void setEntityResolver(@Nullable EntityResolver entityResolver) { this.entityResolver = entityResolver; } @Override @Nullable public EntityResolver getEntityResolver() { return this.entityResolver; } @Override public void setErrorHandler(@Nullable ErrorHandler errorHandler) { this.errorHandler = errorHandler; } @Override @Nullable public ErrorHandler getErrorHandler() { return this.errorHandler; } @Nullable protected LexicalHandler getLexicalHandler() { return this.lexicalHandler; } @Override public boolean getFeature(String name) throws SAXNotRecognizedException { throw new SAXNotRecognizedException(name); } @Override public void setFeature(String name, boolean value) throws SAXNotRecognizedException { throw new SAXNotRecognizedException(name); } @Override @Nullable public Object getProperty(String name) throws SAXNotRecognizedException { if ("http://xml.org/sax/properties/lexical-handler".equals(name)) { return this.lexicalHandler; } else { throw new SAXNotRecognizedException(name); } } @Override public void setProperty(String name, Object value) throws SAXNotRecognizedException { if ("http://xml.org/sax/properties/lexical-handler".equals(name)) { this.lexicalHandler = (LexicalHandler) value; } else { throw new SAXNotRecognizedException(name); } } @Override public void parse(InputSource input) throws SAXException { parse(); } @Override public void parse(String systemId) throws SAXException { parse(); } private void parse() throws SAXException { SAXResult result = new SAXResult(getContentHandler()); result.setLexicalHandler(getLexicalHandler()); try { this.marshaller.marshal(this.content, result); } catch (IOException ex) { SAXParseException saxException = new SAXParseException(ex.getMessage(), null, null, -1, -1, ex); ErrorHandler errorHandler = getErrorHandler(); if (errorHandler != null) { errorHandler.fatalError(saxException); } else { throw saxException; } } } } }