/*
* Copyright 2002-2008 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
*
* 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.springframework.web.servlet.view.jasperreports;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import javax.servlet.http.HttpServletResponse;
import net.sf.jasperreports.engine.JasperPrint;
import org.springframework.beans.BeanUtils;
import org.springframework.context.ApplicationContextException;
import org.springframework.util.ClassUtils;
/**
* Jasper Reports view class that allows for the actual rendering format to be
* specified at runtime using a parameter contained in the model.
*
* <p>This view works on the concept of a format key and a mapping key.
* The format key is used to pass the mapping key from your
* <code>Controller</code> to Spring through as part of the model and the
* mapping key is used to map a logical format to an actual JasperReports
* view class. For example you might add the following code to your
* <code>Controller</code>:
*
* <pre>
* Map model = new HashMap();
* model.put("format", "pdf");</pre>
*
* Here <code>format</code> is the format key and <code>pdf</code> is
* the mapping key. When rendering a report, this class looks for a
* model parameter under the format key, which by default is
* <code>format</code>. It then uses the value of this parameter to lookup
* the actual <code>View</code> class to use. The default mappings for this
* lookup are:
*
* <p><ul>
* <li><code>csv</code> - <code>JasperReportsCsvView</code></li>
* <li><code>html</code> - <code>JasperReportsHtmlView</code></li>
* <li><code>pdf</code> - <code>JasperReportsPdfView</code></li>
* <li><code>xls</code> - <code>JasperReportsXlsView</code></li>
* </ul>
*
* <p>The format key can be changed using the <code>formatKey</code>
* property and the mapping key to view class mappings can be changed using the
* <code>formatMappings</code> property.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 1.1.5
* @see #setFormatKey
* @see #setFormatMappings
*/
public class JasperReportsMultiFormatView extends AbstractJasperReportsView {
/**
* Default value used for format key: "format"
*/
public static final String DEFAULT_FORMAT_KEY = "format";
/**
* The key of the model parameter that holds the format key.
*/
private String formatKey = DEFAULT_FORMAT_KEY;
/**
* Stores the format mappings, with the format discriminator
* as key and the corresponding view class as value.
*/
private Map formatMappings;
/**
* Stores the mappings of mapping keys to Content-Disposition header values.
*/
private Properties contentDispositionMappings;
/**
* Creates a new <code>JasperReportsMultiFormatView</code> instance
* with a default set of mappings.
*/
public JasperReportsMultiFormatView() {
this.formatMappings = new HashMap(4);
this.formatMappings.put("csv", JasperReportsCsvView.class);
this.formatMappings.put("html", JasperReportsHtmlView.class);
this.formatMappings.put("pdf", JasperReportsPdfView.class);
this.formatMappings.put("xls", JasperReportsXlsView.class);
}
/**
* Set the key of the model parameter that holds the format discriminator.
* Default is "format".
*/
public void setFormatKey(String formatKey) {
this.formatKey = formatKey;
}
/**
* Set the mappings of format discriminators to view class names.
* The default mappings are:
* <p><ul>
* <li><code>csv</code> - <code>JasperReportsCsvView</code></li>
* <li><code>html</code> - <code>JasperReportsHtmlView</code></li>
* <li><code>pdf</code> - <code>JasperReportsPdfView</code></li>
* <li><code>xls</code> - <code>JasperReportsXlsView</code></li>
* </ul>
*/
public void setFormatMappings(Properties mappingsWithClassNames) {
if (mappingsWithClassNames == null || mappingsWithClassNames.isEmpty()) {
throw new IllegalArgumentException("formatMappings must not be empty");
}
this.formatMappings = new HashMap(mappingsWithClassNames.size());
for (Enumeration discriminators = mappingsWithClassNames.propertyNames(); discriminators.hasMoreElements();) {
String discriminator = (String) discriminators.nextElement();
String className = mappingsWithClassNames.getProperty(discriminator);
try {
if (logger.isDebugEnabled()) {
logger.debug("Mapped view class [" + className + "] to mapping key [" + discriminator + "]");
}
this.formatMappings.put(discriminator, ClassUtils.forName(className));
}
catch (ClassNotFoundException ex) {
throw new ApplicationContextException(
"Class [" + className + "] mapped to format [" + discriminator + "] cannot be found", ex);
}
}
}
/**
* Set the mappings of <code>Content-Disposition</code> header values to
* mapping keys. If specified, Spring will look at these mappings to determine
* the value of the <code>Content-Disposition</code> header for a given
* format mapping.
*/
public void setContentDispositionMappings(Properties mappings) {
this.contentDispositionMappings = mappings;
}
/**
* Return the mappings of <code>Content-Disposition</code> header values to
* mapping keys. Mainly available for configuration through property paths
* that specify individual keys.
*/
public Properties getContentDispositionMappings() {
if (this.contentDispositionMappings == null) {
this.contentDispositionMappings = new Properties();
}
return this.contentDispositionMappings;
}
protected boolean generatesDownloadContent() {
return true;
}
/**
* Locates the format key in the model using the configured discriminator key and uses this
* key to lookup the appropriate view class from the mappings. The rendering of the
* report is then delegated to an instance of that view class.
*/
protected void renderReport(JasperPrint populatedReport, Map model, HttpServletResponse response)
throws Exception {
String format = (String) model.get(this.formatKey);
if (format == null) {
throw new IllegalArgumentException("No format format found in model");
}
if (logger.isDebugEnabled()) {
logger.debug("Rendering report using format mapping key [" + format + "]");
}
Class viewClass = (Class) this.formatMappings.get(format);
if (viewClass == null) {
throw new IllegalArgumentException("Format discriminator [" + format + "] is not a configured mapping");
}
if (logger.isDebugEnabled()) {
logger.debug("Rendering report using view class [" + viewClass.getName() + "]");
}
AbstractJasperReportsView view = (AbstractJasperReportsView) BeanUtils.instantiateClass(viewClass);
// Copy appropriate properties across.
view.setExporterParameters(getExporterParameters());
// Can skip most initialization since all relevant URL processing
// has been done - just need to convert parameters on the sub view.
view.convertExporterParameters();
// Prepare response and render report.
populateContentDispositionIfNecessary(response, format);
view.renderReport(populatedReport, model, response);
}
/**
* Adds/overwrites the <code>Content-Disposition</code> header value with the format-specific
* value if the mappings have been specified and a valid one exists for the given format.
* @param response the <code>HttpServletResponse</code> to set the header in
* @param format the format key of the mapping
* @see #setContentDispositionMappings
*/
private void populateContentDispositionIfNecessary(HttpServletResponse response, String format) {
if (this.contentDispositionMappings != null) {
String header = this.contentDispositionMappings.getProperty(format);
if (header != null) {
if (logger.isDebugEnabled()) {
logger.debug("Setting Content-Disposition header to: [" + header + "]");
}
response.setHeader(HEADER_CONTENT_DISPOSITION, header);
}
}
}
}