Java tutorial
/* =================================================================== * SimpleXmlView.java * * Created Aug 14, 2008 5:07:50 PM * * Copyright (c) 2008 Solarnetwork.net Dev Team. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 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 * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA * 02111-1307 USA * =================================================================== */ package net.solarnetwork.web.support; import java.io.IOException; import java.io.OutputStreamWriter; import java.io.UnsupportedEncodingException; import java.io.Writer; import java.text.SimpleDateFormat; import java.util.Collection; import java.util.Date; import java.util.LinkedHashMap; import java.util.Map; import java.util.Set; import java.util.TimeZone; import java.util.regex.Matcher; import java.util.regex.Pattern; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.solarnetwork.util.ClassUtils; /** * Spring {@link org.springframework.web.servlet.View} for turning objects into * XML through JavaBean introspection. * * <p> * The character encoding of the output must be specified in the * {@link #setContentType(String)} (e.g. {@literal text/xml;charset=UTF-8}). * </p> * * <p> * The configurable properties of this class are: * </p> * * <dl> * <dt>rootElementName</dt> * <dd>The name of the root XML element to use.</dd> * * <dt>singleBeanAsRoot</dt> * <dd>TODO</dd> * * <dt>useModelTimeZoneForDates</dt> * <dd>TODO</dd> * * <dt>modelKey</dt> * <dd>TODO</dd> * * <dt>rootElementAugmentor</dt> * <dd>TODO</dd> * * <dt>classNamesAllowedForNesting</dt> * <dd>TODO</dd> * </dl> * * @author matt * @version 1.1 */ public class SimpleXmlView extends AbstractView { /** Default content type. */ public static final String DEFAULT_XML_CONTENT_TYPE = "text/xml;charset=UTF-8"; private static final ThreadLocal<SimpleDateFormat> SDF = new ThreadLocal<SimpleDateFormat>(); private static final Pattern AMP = Pattern.compile("&(?!\\w+;)"); private String rootElementName = "root"; private boolean singleBeanAsRoot = true; private boolean useModelTimeZoneForDates = true; private String modelKey = null; private ViewResponseAugmentor rootElementAugmentor = null; private Set<String> classNamesAllowedForNesting = null; /** * Constructor. */ public SimpleXmlView() { setContentType(DEFAULT_XML_CONTENT_TYPE); } @Override protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception { Map<String, Object> finalModel = setupDateFormat(model); response.setContentType(getContentType()); String charset = getResponseCharacterEncoding(); OutputStreamWriter out; try { out = new OutputStreamWriter(response.getOutputStream(), charset); } catch (UnsupportedEncodingException e) { throw new RuntimeException(e); } // write XML start out.write("<?xml version=\"1.0\" encoding=\""); out.write(charset); out.write("\"?>\n"); Object singleBean = finalModel.size() == 1 && this.singleBeanAsRoot ? finalModel.values().iterator().next() : null; if (singleBean != null) { outputObject(singleBean, finalModel.keySet().iterator().next().toString(), out, rootElementAugmentor); } else { writeElement(this.rootElementName, null, out, false, rootElementAugmentor); for (Map.Entry<String, Object> me : finalModel.entrySet()) { outputObject(me.getValue(), me.getKey(), out, null); } // end root element closeElement(this.rootElementName, out); } out.flush(); SDF.remove(); } /** * Create a {@link SimpleDateFormat} and cache on the {@link #SDF} * ThreadLocal to re-use for all dates within a single response. * * @param model * the model, to look for a TimeZone to format the dates in */ private Map<String, Object> setupDateFormat(Map<String, Object> model) { TimeZone tz = TimeZone.getTimeZone("GMT"); Map<String, Object> result = new LinkedHashMap<String, Object>(); for (Map.Entry<String, Object> me : model.entrySet()) { Object o = me.getValue(); if (useModelTimeZoneForDates && o instanceof TimeZone) { tz = (TimeZone) o; } else if (modelKey != null) { if (modelKey.equals(me.getKey())) { result.put(modelKey, o); } } else { //if ( !(o instanceof BindingResult) ) { result.put(me.getKey(), o); } } SimpleDateFormat sdf = new SimpleDateFormat(); if (tz.getRawOffset() == 0) { sdf.applyPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); } else { sdf.applyPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ"); } sdf.setTimeZone(tz); if (logger.isTraceEnabled()) { logger.trace("TZ offset " + tz.getRawOffset()); } SDF.set(sdf); return result; } private void outputObject(Object o, String name, Writer out, ViewResponseAugmentor augmentor) throws IOException { if (o instanceof Collection) { Collection<?> col = (Collection<?>) o; outputCollection(col, name, out, augmentor); } else if (o instanceof Map) { Map<?, ?> map = (Map<?, ?>) o; outputMap(map, name, out, augmentor); } else if (o instanceof String || o instanceof Number) { // for simple types, write as unified <value type="String" value="foo"/> // this happens often in collections / maps of simple data types Map<String, Object> params = new LinkedHashMap<String, Object>(2); params.put("type", org.springframework.util.ClassUtils.getShortName(o.getClass())); params.put("value", o); writeElement("value", params, out, true, augmentor); } else { String elementName = (o == null ? name : org.springframework.util.ClassUtils.getShortName(o.getClass())); writeElement(elementName, o, out, true, augmentor); } } private void outputMap(Map<?, ?> map, String name, Writer out, ViewResponseAugmentor augmentor) throws IOException { writeElement(name, null, out, false, augmentor); // for each entry, write an <entry> element for (Map.Entry<?, ?> me : map.entrySet()) { String entryName = me.getKey().toString(); out.write("<entry key=\""); out.write(entryName); out.write("\">"); Object value = me.getValue(); if (value instanceof Collection) { // special collection case, we don't add nested element for (Object o : (Collection<?>) value) { outputObject(o, "value", out, augmentor); } } else { outputObject(value, null, out, augmentor); } closeElement("entry", out); } closeElement(name, out); } private void outputCollection(Collection<?> col, String name, Writer out, ViewResponseAugmentor augmentor) throws IOException { writeElement(name, null, out, false, augmentor); for (Object o : col) { outputObject(o, null, out, null); } closeElement(name, out); } private void writeElement(String name, Map<?, ?> props, Writer out, boolean close, ViewResponseAugmentor augmentor) throws IOException { out.write('<'); out.write(name); if (augmentor != null) { augmentor.augmentResponse(out); } Map<String, Object> nested = null; if (props != null) { for (Map.Entry<?, ?> me : props.entrySet()) { String key = me.getKey().toString(); Object val = me.getValue(); if (getPropertySerializerRegistrar() != null) { val = getPropertySerializerRegistrar().serializeProperty(name, val.getClass(), props, val); } if (val instanceof Date) { SimpleDateFormat sdf = SDF.get(); // SimpleDateFormat has no way to create xs:dateTime with tz, // so use trick here to insert required colon for non GMT dates Date date = (Date) val; StringBuilder buf = new StringBuilder(sdf.format(date)); if (buf.charAt(buf.length() - 1) != 'Z') { buf.insert(buf.length() - 2, ':'); } val = buf.toString(); } else if (val instanceof Collection) { if (nested == null) { nested = new LinkedHashMap<String, Object>(5); } nested.put(key, val); val = null; } else if (val instanceof Map<?, ?>) { if (nested == null) { nested = new LinkedHashMap<String, Object>(5); } nested.put(key, val); val = null; } else if (classNamesAllowedForNesting != null && !(val instanceof Enum<?>)) { for (String prefix : classNamesAllowedForNesting) { if (val.getClass().getName().startsWith(prefix)) { if (nested == null) { nested = new LinkedHashMap<String, Object>(5); } nested.put(key, val); val = null; break; } } } if (val != null) { // replace & with & String attVal = val.toString(); Matcher matcher = AMP.matcher(attVal); attVal = matcher.replaceAll("&"); attVal = attVal.replace("\"", """); out.write(' '); out.write(key); out.write("=\""); out.write(attVal); out.write('"'); } } } if (close && nested == null) { out.write('/'); } out.write('>'); if (nested != null) { for (Map.Entry<String, Object> me : nested.entrySet()) { outputObject(me.getValue(), me.getKey(), out, augmentor); } if (close) { closeElement(name, out); } } } private void writeElement(String name, Object bean, Writer out, boolean close, ViewResponseAugmentor augmentor) throws IOException { if (getPropertySerializerRegistrar() != null && bean != null) { // try whole-bean serialization first Object o = getPropertySerializerRegistrar().serializeProperty(name, bean.getClass(), bean, bean); if (o != bean) { if (o != null) { outputObject(o, name, out, augmentor); } return; } } Map<String, Object> props = ClassUtils.getBeanProperties(bean, null, true); writeElement(name, props, out, close, augmentor); } private void closeElement(String name, Writer out) throws IOException { out.write("</"); out.write(name); out.write('>'); } public String getRootElementName() { return rootElementName; } public void setRootElementName(String rootElementName) { this.rootElementName = rootElementName; } public boolean isSingleBeanAsRoot() { return singleBeanAsRoot; } public void setSingleBeanAsRoot(boolean singleBeanAsRoot) { this.singleBeanAsRoot = singleBeanAsRoot; } public boolean isUseModelTimeZoneForDates() { return useModelTimeZoneForDates; } public void setUseModelTimeZoneForDates(boolean useModelTimeZoneForDates) { this.useModelTimeZoneForDates = useModelTimeZoneForDates; } public String getModelKey() { return modelKey; } public void setModelKey(String modelKey) { this.modelKey = modelKey; } public ViewResponseAugmentor getRootElementAugmentor() { return rootElementAugmentor; } public void setRootElementAugmentor(ViewResponseAugmentor rootElementAugmentor) { this.rootElementAugmentor = rootElementAugmentor; } public Set<String> getClassNamesAllowedForNesting() { return classNamesAllowedForNesting; } public void setClassNamesAllowedForNesting(Set<String> classNamesAllowedForNesting) { this.classNamesAllowedForNesting = classNamesAllowedForNesting; } }