Java tutorial
/** * Copyright (C) 2010 Orbeon, Inc. * * This program is free software; you can redistribute it and/or modify it under the terms of the * GNU Lesser General Public License as published by the Free Software Foundation; either version * 2.1 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU Lesser General Public License for more details. * * The full text of the license is available at http://www.gnu.org/copyleft/lesser.html */ package org.orbeon.oxf.processor.sql; import org.apache.log4j.Logger; import org.dom4j.*; import org.orbeon.oxf.common.OXFException; import org.orbeon.oxf.common.ValidationException; import org.orbeon.oxf.pipeline.api.PipelineContext; import org.orbeon.oxf.xml.XMLReceiver; import org.orbeon.oxf.processor.*; import org.orbeon.oxf.processor.sql.interpreters.*; import org.orbeon.oxf.properties.PropertySet; import org.orbeon.oxf.util.LoggerFactory; import org.orbeon.oxf.xml.*; import org.orbeon.oxf.xml.dom4j.Dom4jUtils; import org.orbeon.oxf.xml.dom4j.LocationData; import org.orbeon.oxf.xml.dom4j.LocationSAXWriter; import org.xml.sax.Attributes; import org.xml.sax.ContentHandler; import org.xml.sax.Locator; import org.xml.sax.SAXException; import org.xml.sax.helpers.AttributesImpl; import org.xml.sax.helpers.NamespaceSupport; import java.util.*; /** * This is the SQL processor implementation. * <p/> * TODO: * <p/> * o batch for mass updates when supported * o esql:use-limit-clause, esql:skip-rows, esql:max-rows * <p/> * o The position() and last() functions are not implemented within * sql:for-each it does not appear to be trivial to implement them, because * they are already defined by default. Probably that playing with the Jaxen * Context object will allow a correct implementation. * <p/> * o debugging facilities, i.e. output full query with replaced parameters (even on PreparedStatement) * o support more types in replace mode * <p/> * o sql:choose, sql:if * o sql:variable * o define variables such as: * o $sql:results (?) * o $sql:column-count * o $sql:update-count * o caching options */ public class SQLProcessor extends ProcessorImpl { public static Logger logger = LoggerFactory.createLogger(SQLProcessor.class); public static final String SQL_NAMESPACE_URI = "http://orbeon.org/oxf/xml/sql"; private static final String INPUT_DATASOURCE = "datasource"; public static final String SQL_DATASOURCE_URI = "http://www.orbeon.org/oxf/sql-datasource"; public SQLProcessor() { // Mandatory config input addInputInfo(new ProcessorInputOutputInfo(INPUT_CONFIG, SQL_NAMESPACE_URI)); // Optional datasource input addInputInfo(new ProcessorInputOutputInfo(INPUT_DATASOURCE, SQL_DATASOURCE_URI)); // Optional data input and output addInputInfo(new ProcessorInputOutputInfo(INPUT_DATA)); // For now don't declare it, because it causes problems // addOutputInfo(new ProcessorInputOutputInfo(OUTPUT_DATA)); } @Override public ProcessorOutput createOutput(String name) { // This will be called only if there is an output ProcessorOutput output = new ProcessorOutputImpl(SQLProcessor.this, name) { public void readImpl(PipelineContext context, XMLReceiver xmlReceiver) { execute(context, xmlReceiver); } }; addOutput(name, output); return output; } @Override public void start(PipelineContext context) { // This will be called only if no output is connected execute(context, new XMLReceiverAdapter()); } private static class Config { public Config(SAXStore configInput, boolean useXPathExpressions, List xpathExpressions) { this.configInput = configInput; this.useXPathExpressions = useXPathExpressions; this.xpathExpressions = xpathExpressions; } public SAXStore configInput; public boolean useXPathExpressions; public List xpathExpressions; } protected void execute(final PipelineContext context, XMLReceiver xmlReceiver) { try { // Cache, read and interpret the config input Config config = readCacheInputAsObject(context, getInputByName(INPUT_CONFIG), new CacheableInputReader<Config>() { public Config read(PipelineContext context, ProcessorInput input) { // Read the config input document Node config = readInputAsDOM4J(context, input); Document configDocument = config.getDocument(); // Extract XPath expressions and also check whether any XPath expression is used at all // NOTE: This could be done through streaming below as well // NOTE: For now, just match <sql:param select="/*" type="xs:base64Binary"/> List xpathExpressions = new ArrayList(); boolean useXPathExpressions = false; for (Iterator i = XPathUtils.selectIterator(configDocument, "//*[namespace-uri() = '" + SQL_NAMESPACE_URI + "' and @select]"); i .hasNext();) { Element element = (Element) i.next(); useXPathExpressions = true; String typeAttribute = element.attributeValue("type"); if ("xs:base64Binary".equals(typeAttribute)) { String selectAttribute = element.attributeValue("select"); xpathExpressions.add(selectAttribute); } } // Normalize spaces. What this does is to coalesce adjacent text nodes, and to remove // resulting empty text, unless the text is contained within a sql:text element. configDocument.accept(new VisitorSupport() { private boolean endTextSequence(Element element, Text previousText) { if (previousText != null) { String value = previousText.getText(); if (value == null || value.trim().equals("")) { element.remove(previousText); return true; } } return false; } @Override public void visit(Element element) { // Don't touch text within sql:text elements if (!SQL_NAMESPACE_URI.equals(element.getNamespaceURI()) || !"text".equals(element.getName())) { Text previousText = null; for (int i = 0, size = element.nodeCount(); i < size;) { Node node = element.node(i); if (node instanceof Text) { Text text = (Text) node; if (previousText != null) { previousText.appendText(text.getText()); element.remove(text); } else { String value = text.getText(); // Remove empty text nodes if (value == null || value.length() < 1) { element.remove(text); } else { previousText = text; i++; } } } else { if (!endTextSequence(element, previousText)) i++; previousText = null; } } endTextSequence(element, previousText); } } }); // Create SAXStore try { final SAXStore store = new SAXStore(); final LocationSAXWriter locationSAXWriter = new LocationSAXWriter(); locationSAXWriter.setContentHandler(store); locationSAXWriter.write(configDocument); // Return the normalized document return new Config(store, useXPathExpressions, xpathExpressions); } catch (SAXException e) { throw new OXFException(e); } } }); // Either read the whole input as a DOM, or try to serialize Node data = null; XPathXMLReceiver xpathReceiver = null; // Check if the data input is connected boolean hasDataInput = getConnectedInputs().get(INPUT_DATA) != null; if (!hasDataInput && config.useXPathExpressions) throw new OXFException( "The data input must be connected when the configuration uses XPath expressions."); if (!hasDataInput || !config.useXPathExpressions) { // Just use an empty document data = Dom4jUtils.NULL_DOCUMENT; } else { // There is a data input connected and there are some XPath expressions operating on it boolean useXPathContentHandler = false; if (config.xpathExpressions.size() > 0) { // Create XPath content handler final XPathXMLReceiver _xpathReceiver = new XPathXMLReceiver(); // Add expressions and check whether we can try to stream useXPathContentHandler = true; for (Iterator i = config.xpathExpressions.iterator(); i.hasNext();) { String expression = (String) i.next(); boolean canStream = _xpathReceiver.addExpresssion(expression, false);// FIXME: boolean nodeSet if (!canStream) { useXPathContentHandler = false; break; } } // Finish setting up the XPathContentHandler if (useXPathContentHandler) { _xpathReceiver.setReadInputCallback(new Runnable() { public void run() { readInputAsSAX(context, INPUT_DATA, _xpathReceiver); } }); xpathReceiver = _xpathReceiver; } } // If we can't stream, read everything in if (!useXPathContentHandler) data = readInputAsDOM4J(context, INPUT_DATA); } // Try to read datasource input if any Datasource datasource = null; { List datasourceInputs = (List) getConnectedInputs().get(INPUT_DATASOURCE); if (datasourceInputs != null) { if (datasourceInputs.size() > 1) throw new OXFException("At most one one datasource input can be connected."); ProcessorInput datasourceInput = (ProcessorInput) datasourceInputs.get(0); datasource = Datasource.getDatasource(context, this, datasourceInput); } } // Replay the config SAX store through the interpreter config.configInput.replay( new RootInterpreter(context, getPropertySet(), data, datasource, xpathReceiver, xmlReceiver)); } catch (OXFException e) { throw e; } catch (Exception e) { throw new OXFException(e); } } private static class RootInterpreter extends InterpreterContentHandler { private SQLProcessorInterpreterContext interpreterContext; private NamespaceSupport namespaceSupport = new NamespaceSupport(); public RootInterpreter(PipelineContext context, PropertySet propertySet, Node input, Datasource datasource, XPathXMLReceiver xpathReceiver, XMLReceiver output) { super(null, false); interpreterContext = new SQLProcessorInterpreterContext(propertySet); interpreterContext.setPipelineContext(context); interpreterContext.setInput(input); interpreterContext.setDatasource(datasource); interpreterContext.setXPathContentHandler(xpathReceiver); interpreterContext.setOutput(new DeferredXMLReceiverImpl(output)); interpreterContext.setNamespaceSupport(namespaceSupport); addElementHandler(new ConfigInterpreter(interpreterContext), SQL_NAMESPACE_URI, "config"); } @Override public void startElement(String uri, String localname, String qName, Attributes attributes) throws SAXException { try { namespaceSupport.pushContext(); super.startElement(uri, localname, qName, attributes); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void endElement(String uri, String localname, String qName) throws SAXException { try { super.endElement(uri, localname, qName); namespaceSupport.popContext(); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void startPrefixMapping(String prefix, String uri) throws SAXException { try { super.startPrefixMapping(prefix, uri); interpreterContext.declarePrefix(prefix, uri); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void characters(char[] chars, int start, int length) throws SAXException { try { super.characters(chars, start, length); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void endDocument() throws SAXException { try { super.endDocument(); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void ignorableWhitespace(char[] chars, int start, int length) throws SAXException { try { super.ignorableWhitespace(chars, start, length); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void processingInstruction(String s, String s1) throws SAXException { try { super.processingInstruction(s, s1); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void skippedEntity(String s) throws SAXException { try { super.skippedEntity(s); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void startDocument() throws SAXException { try { super.startDocument(); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void endPrefixMapping(String s) throws SAXException { try { super.endPrefixMapping(s); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public Locator getDocumentLocator() { try { return super.getDocumentLocator(); } catch (Exception t) { dispose(); throw new OXFException(t); } } @Override public void setDocumentLocator(Locator locator) { try { super.setDocumentLocator(locator); } catch (Exception t) { dispose(); throw new OXFException(t); } } private void dispose() { // NOTE: Don't do this anymore: the connection will be closed when the context is destroyed } } public static class InterpreterContentHandler extends ForwardingContentHandler { private SQLProcessorInterpreterContext interpreterContext; private Locator documentLocator; private boolean forward; private boolean repeating; private SAXStore saxStore; private DeferredXMLReceiver savedOutput; private Attributes savedAttributes; private Map elementHandlers = new HashMap(); private int forwardingLevel = -1; private InterpreterContentHandler currentHandler; private int level = 0; private String currentKey; /** * * * @param interpreterContext current SQLProcessorInterpreterContext * @param repeating set this to true if the body of this handler will be repeated */ public InterpreterContentHandler(SQLProcessorInterpreterContext interpreterContext, boolean repeating) { this.interpreterContext = interpreterContext; this.repeating = repeating; } public void addElementHandler(InterpreterContentHandler handler, String uri, String localname) { elementHandlers.put("{" + uri + "}" + localname, handler); } public void addAllDefaultElementHandlers() { addElementHandler(new ConnectionInterpreter(interpreterContext), SQLProcessor.SQL_NAMESPACE_URI, "connection"); addElementHandler(new DatasourceInterpreter(interpreterContext), SQLProcessor.SQL_NAMESPACE_URI, "datasource"); addElementHandler(new ExecuteInterpreter(interpreterContext), SQLProcessor.SQL_NAMESPACE_URI, "execute"); final GetterInterpreter getterInterpreter = new GetterInterpreter(interpreterContext); // Legacy getters addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-string"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-int"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-double"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-decimal"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-date"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-timestamp"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-column-value"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-column-type"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-column-name"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-column-index"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-column"); addElementHandler(getterInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "get-columns"); addElementHandler(new TextInterpreter(interpreterContext), SQLProcessor.SQL_NAMESPACE_URI, "text"); addElementHandler(new ColumnIteratorInterpreter(getInterpreterContext()), SQLProcessor.SQL_NAMESPACE_URI, "column-iterator"); addElementHandler(new ForEachInterpreter(getInterpreterContext()), SQLProcessor.SQL_NAMESPACE_URI, "for-each"); addElementHandler(new ExecuteInterpreter(getInterpreterContext()), SQLProcessor.SQL_NAMESPACE_URI, "execute"); addElementHandler(new QueryInterpreter(interpreterContext, QueryInterpreter.QUERY), SQLProcessor.SQL_NAMESPACE_URI, "query"); addElementHandler(new QueryInterpreter(interpreterContext, QueryInterpreter.UPDATE), SQLProcessor.SQL_NAMESPACE_URI, "update"); addElementHandler(new QueryInterpreter(interpreterContext, QueryInterpreter.CALL), SQLProcessor.SQL_NAMESPACE_URI, "call"); final ResultSetInterpreter resultSetInterpreter = new ResultSetInterpreter(interpreterContext); addElementHandler(resultSetInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "results"); addElementHandler(resultSetInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "result-set"); addElementHandler(new NoResultsInterpreter(interpreterContext), SQLProcessor.SQL_NAMESPACE_URI, "no-results"); final RowIteratorInterpreter rowIteratorInterpreter = new RowIteratorInterpreter( getInterpreterContext()); addElementHandler(rowIteratorInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "row-results"); addElementHandler(rowIteratorInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "row-iterator"); final ValueOfCopyOfInterpreter valueOfCopyOfInterpreter = new ValueOfCopyOfInterpreter( interpreterContext); addElementHandler(valueOfCopyOfInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "value-of"); addElementHandler(valueOfCopyOfInterpreter, SQLProcessor.SQL_NAMESPACE_URI, "copy-of"); addElementHandler(new AttributeInterpreter(interpreterContext), SQLProcessor.SQL_NAMESPACE_URI, "attribute"); } @Override public void startElement(String uri, String localname, String qName, Attributes attributes) throws SAXException { if (forwardingLevel == -1 && elementHandlers.size() > 0) { final String key = "{" + uri + "}" + localname; final InterpreterContentHandler elementHandler = (InterpreterContentHandler) elementHandlers .get(key); if (elementHandler != null) { // Found element handler forwardingLevel = level; currentKey = key; if (elementHandler.isRepeating()) { // Remember SAX content of the element body savedOutput = getInterpreterContext().getOutput(); savedAttributes = new AttributesImpl(attributes); elementHandler.saxStore = new SAXStore(); elementHandler.saxStore.setDocumentLocator(documentLocator); getInterpreterContext().setOutput(new DeferredXMLReceiverImpl(elementHandler.saxStore)); } else { // Notify start of element currentHandler = elementHandler; elementHandler.setDocumentLocator(documentLocator); elementHandler.start(uri, localname, qName, attributes); } } else super.startElement(uri, localname, qName, attributes); } else super.startElement(uri, localname, qName, attributes); level++; } @Override public void endElement(String uri, String localname, String qName) throws SAXException { level--; if (forwardingLevel == level) { final String key = "{" + uri + "}" + localname; if (!currentKey.equals(key)) throw new ValidationException("Illegal document: expecting " + key + ", got " + currentKey, new LocationData(getDocumentLocator())); final InterpreterContentHandler elementHandler = (InterpreterContentHandler) elementHandlers .get(key); if (elementHandler.isRepeating()) { // Restore output interpreterContext.setOutput(savedOutput); savedOutput = null; // Notify start of element currentHandler = elementHandler; elementHandler.setDocumentLocator(documentLocator); elementHandler.start(uri, localname, qName, savedAttributes); // Restore state savedAttributes = null; elementHandler.saxStore = null; } // Notify end of element forwardingLevel = -1; currentKey = null; currentHandler = null; elementHandler.end(uri, localname, qName); } else super.endElement(uri, localname, qName); } protected void repeatBody() throws SAXException { if (!repeating) throw new IllegalStateException("repeatBody() can only be called when repeating is true."); saxStore.replay(this); } public boolean isRepeating() { return repeating; } protected void setForward(boolean forward) { this.forward = forward; } @Override public void setDocumentLocator(Locator locator) { this.documentLocator = locator; super.setDocumentLocator(locator); } public Locator getDocumentLocator() { return documentLocator; } @Override public void startPrefixMapping(String s, String s1) throws SAXException { super.startPrefixMapping(s, s1); } public void start(String uri, String localname, String qName, Attributes attributes) throws SAXException { } public void end(String uri, String localname, String qName) throws SAXException { } protected boolean isInElementHandler() { return forwardingLevel > -1; } protected ContentHandler getContentHandler() { // The purpose of the code below is to determine whether SAX events are sent to an // element handler or directly to the output if (currentHandler != null) return currentHandler; else if (forward) return interpreterContext.getOutput(); else return null; } @Override public void characters(char[] chars, int start, int length) throws SAXException { if (currentHandler == null) { // Output only if the string is non-blank [FIXME: Incorrect white space handling!] // String s = new String(chars, start, length); // if (!s.trim().equals("")) super.characters(chars, start, length); } else { super.characters(chars, start, length); } } public SQLProcessorInterpreterContext getInterpreterContext() { return interpreterContext; } } public static abstract class ForwardingContentHandler implements XMLReceiver { public ForwardingContentHandler() { } protected abstract ContentHandler getContentHandler(); public void characters(char[] chars, int start, int length) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.characters(chars, start, length); } public void endDocument() throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.endDocument(); } public void endElement(String uri, String localname, String qName) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.endElement(uri, localname, qName); } public void endPrefixMapping(String s) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.endPrefixMapping(s); } public void ignorableWhitespace(char[] chars, int start, int length) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.ignorableWhitespace(chars, start, length); } public void processingInstruction(String s, String s1) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.processingInstruction(s, s1); } public void setDocumentLocator(Locator locator) { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.setDocumentLocator(locator); } public void skippedEntity(String s) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.skippedEntity(s); } public void startDocument() throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.startDocument(); } public void startElement(String uri, String localname, String qName, Attributes attributes) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.startElement(uri, localname, qName, attributes); } public void startPrefixMapping(String s, String s1) throws SAXException { final ContentHandler contentHandler = getContentHandler(); if (contentHandler != null) contentHandler.startPrefixMapping(s, s1); } // Ignore LexicalHandler methods as we don't plan to do anything useful with them public void startDTD(String name, String publicId, String systemId) throws SAXException { } public void endDTD() throws SAXException { } public void startEntity(String name) throws SAXException { } public void endEntity(String name) throws SAXException { } public void startCDATA() throws SAXException { } public void endCDATA() throws SAXException { } public void comment(char[] ch, int start, int length) throws SAXException { } } }