/*
* Copyright 2002-2010 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.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;
import net.sf.jasperreports.engine.JRDataSource;
import net.sf.jasperreports.engine.JRDataSourceProvider;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JRExporterParameter;
import net.sf.jasperreports.engine.JRParameter;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.design.JasperDesign;
import net.sf.jasperreports.engine.util.JRLoader;
import net.sf.jasperreports.engine.xml.JRXmlLoader;
import org.springframework.context.ApplicationContextException;
import org.springframework.context.support.MessageSourceResourceBundle;
import org.springframework.core.io.Resource;
import org.springframework.ui.jasperreports.JasperReportsUtils;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.web.servlet.support.RequestContext;
import org.springframework.web.servlet.view.AbstractUrlBasedView;
/**
* Base class for all JasperReports views. Applies on-the-fly compilation
* of report designs as required and coordinates the rendering process.
* The resource path of the main report needs to be specified as <code>url</code>.
*
* <p>This class is responsible for getting report data from the model that has
* been provided to the view. The default implementation checks for a model object
* under the specified <code>reportDataKey</code> first, then falls back to looking
* for a value of type <code>JRDataSource</code>, <code>java.util.Collection</code>,
* object array (in that order).
*
* <p>If no <code>JRDataSource</code> can be found in the model, then reports will
* be filled using the configured <code>javax.sql.DataSource</code> if any. If neither
* a <code>JRDataSource</code> or <code>javax.sql.DataSource</code> is available then
* an <code>IllegalArgumentException</code> is raised.
*
* <p>Provides support for sub-reports through the <code>subReportUrls</code> and
* <code>subReportDataKeys</code> properties.
*
* <p>When using sub-reports, the master report should be configured using the
* <code>url</code> property and the sub-reports files should be configured using
* the <code>subReportUrls</code> property. Each entry in the <code>subReportUrls</code>
* Map corresponds to an individual sub-report. The key of an entry must match up
* to a sub-report parameter in your report file of type
* <code>net.sf.jasperreports.engine.JasperReport</code>,
* and the value of an entry must be the URL for the sub-report file.
*
* <p>For sub-reports that require an instance of <code>JRDataSource</code>, that is,
* they don't have a hard-coded query for data retrieval, you can include the
* appropriate data in your model as would with the data source for the parent report.
* However, you must provide a List of parameter names that need to be converted to
* <code>JRDataSource</code> instances for the sub-report via the
* <code>subReportDataKeys</code> property. When using <code>JRDataSource</code>
* instances for sub-reports, you <i>must</i> specify a value for the
* <code>reportDataKey</code> property, indicating the data to use for the main report.
*
* <p>Allows for exporter parameters to be configured declatively using the
* <code>exporterParameters</code> property. This is a <code>Map</code> typed
* property where the key of an entry corresponds to the fully-qualified name
* of the static field for the <code>JRExporterParameter</code> and the value
* of an entry is the value you want to assign to the exporter parameter.
*
* <p>Response headers can be controlled via the <code>headers</code> property. Spring
* will attempt to set the correct value for the <code>Content-Diposition</code> header
* so that reports render correctly in Internet Explorer. However, you can override this
* setting through the <code>headers</code> property.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 1.1.3
* @see #setUrl
* @see #setReportDataKey
* @see #setSubReportUrls
* @see #setSubReportDataKeys
* @see #setHeaders
* @see #setExporterParameters
* @see #setJdbcDataSource
*/
public abstract class AbstractJasperReportsView extends AbstractUrlBasedView {
/**
* Constant that defines "Content-Disposition" header.
*/
protected static final String HEADER_CONTENT_DISPOSITION = "Content-Disposition";
/**
* The default Content-Disposition header. Used to make IE play nice.
*/
protected static final String CONTENT_DISPOSITION_INLINE = "inline";
/**
* A String key used to lookup the <code>JRDataSource</code> in the model.
*/
private String reportDataKey;
/**
* Stores the paths to any sub-report files used by this top-level report,
* along with the keys they are mapped to in the top-level report file.
*/
private Properties subReportUrls;
/**
* Stores the names of any data source objects that need to be converted to
* <code>JRDataSource</code> instances and included in the report parameters
* to be passed on to a sub-report.
*/
private String[] subReportDataKeys;
/**
* Stores the headers to written with each response
*/
private Properties headers;
/**
* Stores the exporter parameters passed in by the user as passed in by the user. May be keyed as
* <code>String</code>s with the fully qualified name of the exporter parameter field.
*/
private Map<?, ?> exporterParameters = new HashMap<Object, Object>();
/**
* Stores the converted exporter parameters - keyed by <code>JRExporterParameter</code>.
*/
private Map<JRExporterParameter, Object> convertedExporterParameters;
/**
* Stores the <code>DataSource</code>, if any, used as the report data source.
*/
private DataSource jdbcDataSource;
/**
* The <code>JasperReport</code> that is used to render the view.
*/
private JasperReport report;
/**
* Holds mappings between sub-report keys and <code>JasperReport</code> objects.
*/
private Map<String, JasperReport> subReports;
/**
* Set the name of the model attribute that represents the report data.
* If not specified, the model map will be searched for a matching value type.
* <p>A <code>JRDataSource</code> will be taken as-is. For other types, conversion
* will apply: By default, a <code>java.util.Collection</code> will be converted
* to <code>JRBeanCollectionDataSource</code>, and an object array to
* <code>JRBeanArrayDataSource</code>.
* <p><b>Note:</b> If you pass in a Collection or object array in the model map
* for use as plain report parameter, rather than as report data to extract fields
* from, you need to specify the key for the actual report data to use, to avoid
* mis-detection of report data by type.
* @see #convertReportData
* @see net.sf.jasperreports.engine.JRDataSource
* @see net.sf.jasperreports.engine.data.JRBeanCollectionDataSource
* @see net.sf.jasperreports.engine.data.JRBeanArrayDataSource
*/
public void setReportDataKey(String reportDataKey) {
this.reportDataKey = reportDataKey;
}
/**
* Specify resource paths which must be loaded as instances of
* <code>JasperReport</code> and passed to the JasperReports engine for
* rendering as sub-reports, under the same keys as in this mapping.
* @param subReports mapping between model keys and resource paths
* (Spring resource locations)
* @see #setUrl
* @see org.springframework.context.ApplicationContext#getResource
*/
public void setSubReportUrls(Properties subReports) {
this.subReportUrls = subReports;
}
/**
* Set the list of names corresponding to the model parameters that will contain
* data source objects for use in sub-reports. Spring will convert these objects
* to instances of <code>JRDataSource</code> where applicable and will then
* include the resulting <code>JRDataSource</code> in the parameters passed into
* the JasperReports engine.
* <p>The name specified in the list should correspond to an attribute in the
* model Map, and to a sub-report data source parameter in your report file.
* If you pass in <code>JRDataSource</code> objects as model attributes,
* specifing this list of keys is not required.
* <p>If you specify a list of sub-report data keys, it is required to also
* specify a <code>reportDataKey</code> for the main report, to avoid confusion
* between the data source objects for the various reports involved.
* @param subReportDataKeys list of names for sub-report data source objects
* @see #setReportDataKey
* @see #convertReportData
* @see net.sf.jasperreports.engine.JRDataSource
* @see net.sf.jasperreports.engine.data.JRBeanCollectionDataSource
* @see net.sf.jasperreports.engine.data.JRBeanArrayDataSource
*/
public void setSubReportDataKeys(String[] subReportDataKeys) {
this.subReportDataKeys = subReportDataKeys;
}
/**
* Specify the set of headers that are included in each of response.
* @param headers the headers to write to each response.
*/
public void setHeaders(Properties headers) {
this.headers = headers;
}
/**
* Set the exporter parameters that should be used when rendering a view.
* @param parameters <code>Map</code> with the fully qualified field name
* of the <code>JRExporterParameter</code> instance as key
* (e.g. "net.sf.jasperreports.engine.export.JRHtmlExporterParameter.IMAGES_URI")
* and the value you wish to assign to the parameter as value
*/
public void setExporterParameters(Map<?, ?> parameters) {
this.exporterParameters = parameters;
}
/**
* Return the exporter parameters that this view uses, if any.
*/
public Map<?, ?> getExporterParameters() {
return this.exporterParameters;
}
/**
* Allows subclasses to populate the converted exporter parameters.
*/
protected void setConvertedExporterParameters(Map<JRExporterParameter, Object> convertedExporterParameters) {
this.convertedExporterParameters = convertedExporterParameters;
}
/**
* Allows subclasses to retrieve the converted exporter parameters.
*/
protected Map<JRExporterParameter, Object> getConvertedExporterParameters() {
return this.convertedExporterParameters;
}
/**
* Specify the <code>javax.sql.DataSource</code> to use for reports with
* embedded SQL statements.
*/
public void setJdbcDataSource(DataSource jdbcDataSource) {
this.jdbcDataSource = jdbcDataSource;
}
/**
* Return the <code>javax.sql.DataSource</code> that this view uses, if any.
*/
protected DataSource getJdbcDataSource() {
return this.jdbcDataSource;
}
/**
* JasperReports views do not strictly required a 'url' value.
* Alternatively, the {@link #getReport()} template method may be overridden.
*/
@Override
protected boolean isUrlRequired() {
return false;
}
/**
* Checks to see that a valid report file URL is supplied in the
* configuration. Compiles the report file is necessary.
* <p>Subclasses can add custom initialization logic by overriding
* the {@link #onInit} method.
*/
@Override
protected final void initApplicationContext() throws ApplicationContextException {
this.report = loadReport();
// Load sub reports if required, and check data source parameters.
if (this.subReportUrls != null) {
if (this.subReportDataKeys != null && this.subReportDataKeys.length > 0 && this.reportDataKey == null) {
throw new ApplicationContextException(
"'reportDataKey' for main report is required when specifying a value for 'subReportDataKeys'");
}
this.subReports = new HashMap<String, JasperReport>(this.subReportUrls.size());
for (Enumeration urls = this.subReportUrls.propertyNames(); urls.hasMoreElements();) {
String key = (String) urls.nextElement();
String path = this.subReportUrls.getProperty(key);
Resource resource = getApplicationContext().getResource(path);
this.subReports.put(key, loadReport(resource));
}
}
// Convert user-supplied exporterParameters.
convertExporterParameters();
if (this.headers == null) {
this.headers = new Properties();
}
if (!this.headers.containsKey(HEADER_CONTENT_DISPOSITION)) {
this.headers.setProperty(HEADER_CONTENT_DISPOSITION, CONTENT_DISPOSITION_INLINE);
}
onInit();
}
/**
* Subclasses can override this to add some custom initialization logic. Called
* by {@link #initApplicationContext()} as soon as all standard initialization logic
* has finished executing.
* @see #initApplicationContext()
*/
protected void onInit() {
}
/**
* Converts the exporter parameters passed in by the user which may be keyed
* by <code>String</code>s corresponding to the fully qualified name of the
* <code>JRExporterParameter</code> into parameters which are keyed by
* <code>JRExporterParameter</code>.
* @see #getExporterParameter(Object)
*/
protected final void convertExporterParameters() {
if (!CollectionUtils.isEmpty(this.exporterParameters)) {
this.convertedExporterParameters = new HashMap<JRExporterParameter, Object>(this.exporterParameters.size());
for (Map.Entry<?, ?> entry : this.exporterParameters.entrySet()) {
JRExporterParameter exporterParameter = getExporterParameter(entry.getKey());
this.convertedExporterParameters.put(
exporterParameter, convertParameterValue(exporterParameter, entry.getValue()));
}
}
}
/**
* Convert the supplied parameter value into the actual type required by the
* corresponding {@link JRExporterParameter}.
* <p>The default implementation simply converts the String values "true" and
* "false" into corresponding <code>Boolean</code> objects, and tries to convert
* String values that start with a digit into <code>Integer</code> objects
* (simply keeping them as String if number conversion fails).
* @param parameter the parameter key
* @param value the parameter value
* @return the converted parameter value
*/
protected Object convertParameterValue(JRExporterParameter parameter, Object value) {
if (value instanceof String) {
String str = (String) value;
if ("true".equals(str)) {
return Boolean.TRUE;
}
else if ("false".equals(str)) {
return Boolean.FALSE;
}
else if (str.length() > 0 && Character.isDigit(str.charAt(0))) {
// Looks like a number... let's try.
try {
return new Integer(str);
}
catch (NumberFormatException ex) {
// OK, then let's keep it as a String value.
return str;
}
}
}
return value;
}
/**
* Return a <code>JRExporterParameter</code> for the given parameter object,
* converting it from a String if necessary.
* @param parameter the parameter object, either a String or a JRExporterParameter
* @return a JRExporterParameter for the given parameter object
* @see #convertToExporterParameter(String)
*/
protected JRExporterParameter getExporterParameter(Object parameter) {
if (parameter instanceof JRExporterParameter) {
return (JRExporterParameter) parameter;
}
if (parameter instanceof String) {
return convertToExporterParameter((String) parameter);
}
throw new IllegalArgumentException(
"Parameter [" + parameter + "] is invalid type. Should be either String or JRExporterParameter.");
}
/**
* Convert the given fully qualified field name to a corresponding
* JRExporterParameter instance.
* @param fqFieldName the fully qualified field name, consisting
* of the class name followed by a dot followed by the field name
* (e.g. "net.sf.jasperreports.engine.export.JRHtmlExporterParameter.IMAGES_URI")
* @return the corresponding JRExporterParameter instance
*/
protected JRExporterParameter convertToExporterParameter(String fqFieldName) {
int index = fqFieldName.lastIndexOf('.');
if (index == -1 || index == fqFieldName.length()) {
throw new IllegalArgumentException(
"Parameter name [" + fqFieldName + "] is not a valid static field. " +
"The parameter name must map to a static field such as " +
"[net.sf.jasperreports.engine.export.JRHtmlExporterParameter.IMAGES_URI]");
}
String className = fqFieldName.substring(0, index);
String fieldName = fqFieldName.substring(index + 1);
try {
Class cls = ClassUtils.forName(className, getApplicationContext().getClassLoader());
Field field = cls.getField(fieldName);
if (JRExporterParameter.class.isAssignableFrom(field.getType())) {
try {
return (JRExporterParameter) field.get(null);
}
catch (IllegalAccessException ex) {
throw new IllegalArgumentException(
"Unable to access field [" + fieldName + "] of class [" + className + "]. " +
"Check that it is static and accessible.");
}
}
else {
throw new IllegalArgumentException("Field [" + fieldName + "] on class [" + className +
"] is not assignable from JRExporterParameter - check the type of this field.");
}
}
catch (ClassNotFoundException ex) {
throw new IllegalArgumentException(
"Class [" + className + "] in key [" + fqFieldName + "] could not be found.");
}
catch (NoSuchFieldException ex) {
throw new IllegalArgumentException("Field [" + fieldName + "] in key [" + fqFieldName +
"] could not be found on class [" + className + "].");
}
}
/**
* Load the main <code>JasperReport</code> from the specified <code>Resource</code>.
* If the <code>Resource</code> points to an uncompiled report design file then the
* report file is compiled dynamically and loaded into memory.
* @return a <code>JasperReport</code> instance, or <code>null</code> if no main
* report has been statically defined
*/
protected JasperReport loadReport() {
String url = getUrl();
if (url == null) {
return null;
}
Resource mainReport = getApplicationContext().getResource(url);
return loadReport(mainReport);
}
/**
* Loads a <code>JasperReport</code> from the specified <code>Resource</code>.
* If the <code>Resource</code> points to an uncompiled report design file then
* the report file is compiled dynamically and loaded into memory.
* @param resource the <code>Resource</code> containing the report definition or design
* @return a <code>JasperReport</code> instance
*/
protected final JasperReport loadReport(Resource resource) {
try {
String fileName = resource.getFilename();
if (fileName.endsWith(".jasper")) {
// Load pre-compiled report.
if (logger.isInfoEnabled()) {
logger.info("Loading pre-compiled Jasper Report from " + resource);
}
InputStream is = resource.getInputStream();
try {
return (JasperReport) JRLoader.loadObject(is);
}
finally {
is.close();
}
}
else if (fileName.endsWith(".jrxml")) {
// Compile report on-the-fly.
if (logger.isInfoEnabled()) {
logger.info("Compiling Jasper Report loaded from " + resource);
}
InputStream is = resource.getInputStream();
try {
JasperDesign design = JRXmlLoader.load(is);
return JasperCompileManager.compileReport(design);
}
finally {
is.close();
}
}
else {
throw new IllegalArgumentException(
"Report filename [" + fileName + "] must end in either .jasper or .jrxml");
}
}
catch (IOException ex) {
throw new ApplicationContextException(
"Could not load JasperReports report from " + resource, ex);
}
catch (JRException ex) {
throw new ApplicationContextException(
"Could not parse JasperReports report from " + resource, ex);
}
}
/**
* Finds the report data to use for rendering the report and then invokes the
* {@link #renderReport} method that should be implemented by the subclass.
* @param model the model map, as passed in for view rendering. Must contain
* a report data value that can be converted to a <code>JRDataSource</code>,
* acccording to the rules of the {@link #fillReport} method.
*/
@Override
protected void renderMergedOutputModel(
Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
if (this.subReports != null) {
// Expose sub-reports as model attributes.
model.putAll(this.subReports);
// Transform any collections etc into JRDataSources for sub reports.
if (this.subReportDataKeys != null) {
for (String key : this.subReportDataKeys) {
model.put(key, convertReportData(model.get(key)));
}
}
}
// Expose Spring-managed Locale and MessageSource.
exposeLocalizationContext(model, request);
// Fill the report.
JasperPrint filledReport = fillReport(model);
postProcessReport(filledReport, model);
// Prepare response and render report.
populateHeaders(response);
renderReport(filledReport, model, response);
}
/**
* Expose current Spring-managed Locale and MessageSource to JasperReports i18n
* ($R expressions etc). The MessageSource should only be exposed as JasperReports
* resource bundle if no such bundle is defined in the report itself.
* <p>The default implementation exposes the Spring RequestContext Locale and a
* MessageSourceResourceBundle adapter for the Spring ApplicationContext,
* analogous to the <code>JstlUtils.exposeLocalizationContext</code> method.
* @see org.springframework.web.servlet.support.RequestContextUtils#getLocale
* @see org.springframework.context.support.MessageSourceResourceBundle
* @see #getApplicationContext()
* @see net.sf.jasperreports.engine.JRParameter#REPORT_LOCALE
* @see net.sf.jasperreports.engine.JRParameter#REPORT_RESOURCE_BUNDLE
* @see org.springframework.web.servlet.support.JstlUtils#exposeLocalizationContext
*/
protected void exposeLocalizationContext(Map<String, Object> model, HttpServletRequest request) {
RequestContext rc = new RequestContext(request, getServletContext());
if (!model.containsKey(JRParameter.REPORT_LOCALE)) {
model.put(JRParameter.REPORT_LOCALE, rc.getLocale());
}
JasperReport report = getReport();
if ((report == null || report.getResourceBundle() == null) &&
!model.containsKey(JRParameter.REPORT_RESOURCE_BUNDLE)) {
model.put(JRParameter.REPORT_RESOURCE_BUNDLE,
new MessageSourceResourceBundle(rc.getMessageSource(), rc.getLocale()));
}
}
/**
* Create a populated <code>JasperPrint</code> instance from the configured
* <code>JasperReport</code> instance.
* <p>By default, this method will use any <code>JRDataSource</code> instance
* (or wrappable <code>Object</code>) that can be located using {@link #setReportDataKey},
* a lookup for type <code>JRDataSource</code> in the model Map, or a special value
* retrieved via {@link #getReportData}.
* <p>If no <code>JRDataSource</code> can be found, this method will use a JDBC
* <code>Connection</code> obtained from the configured <code>javax.sql.DataSource</code>
* (or a DataSource attribute in the model). If no JDBC DataSource can be found
* either, the JasperReports engine will be invoked with plain model Map,
* assuming that the model contains parameters that identify the source
* for report data (e.g. Hibernate or JPA queries).
* @param model the model for this request
* @throws IllegalArgumentException if no <code>JRDataSource</code> can be found
* and no <code>javax.sql.DataSource</code> is supplied
* @throws SQLException if there is an error when populating the report using
* the <code>javax.sql.DataSource</code>
* @throws JRException if there is an error when populating the report using
* a <code>JRDataSource</code>
* @return the populated <code>JasperPrint</code> instance
* @see #getReportData
* @see #setJdbcDataSource
*/
protected JasperPrint fillReport(Map<String, Object> model) throws Exception {
// Determine main report.
JasperReport report = getReport();
if (report == null) {
throw new IllegalStateException("No main report defined for 'fillReport' - " +
"specify a 'url' on this view or override 'getReport()' or 'fillReport(Map)'");
}
JRDataSource jrDataSource = null;
DataSource jdbcDataSourceToUse = null;
// Try model attribute with specified name.
if (this.reportDataKey != null) {
Object reportDataValue = model.get(this.reportDataKey);
if (reportDataValue instanceof DataSource) {
jdbcDataSourceToUse = (DataSource) reportDataValue;
}
else {
jrDataSource = convertReportData(reportDataValue);
}
}
else {
Collection values = model.values();
jrDataSource = CollectionUtils.findValueOfType(values, JRDataSource.class);
if (jrDataSource == null) {
JRDataSourceProvider provider = CollectionUtils.findValueOfType(values, JRDataSourceProvider.class);
if (provider != null) {
jrDataSource = createReport(provider);
}
else {
jdbcDataSourceToUse = CollectionUtils.findValueOfType(values, DataSource.class);
if (jdbcDataSourceToUse == null) {
jdbcDataSourceToUse = this.jdbcDataSource;
}
}
}
}
if (jdbcDataSourceToUse != null) {
return doFillReport(report, model, jdbcDataSourceToUse);
}
else {
// Determine JRDataSource for main report.
if (jrDataSource == null) {
jrDataSource = getReportData(model);
}
if (jrDataSource != null) {
// Use the JasperReports JRDataSource.
if (logger.isDebugEnabled()) {
logger.debug("Filling report with JRDataSource [" + jrDataSource + "]");
}
return JasperFillManager.fillReport(report, model, jrDataSource);
}
else {
// Assume that the model contains parameters that identify
// the source for report data (e.g. Hibernate or JPA queries).
logger.debug("Filling report with plain model");
return JasperFillManager.fillReport(report, model);
}
}
}
/**
* Fill the given report using the given JDBC DataSource and model.
*/
private JasperPrint doFillReport(JasperReport report, Map<String, Object> model, DataSource ds) throws Exception {
// Use the JDBC DataSource.
if (logger.isDebugEnabled()) {
logger.debug("Filling report using JDBC DataSource [" + ds + "]");
}
Connection con = ds.getConnection();
try {
return JasperFillManager.fillReport(report, model, con);
}
finally {
try {
con.close();
}
catch (Throwable ex) {
logger.debug("Could not close JDBC Connection", ex);
}
}
}
/**
* Populates the headers in the <code>HttpServletResponse</code> with the
* headers supplied by the user.
*/
private void populateHeaders(HttpServletResponse response) {
// Apply the headers to the response.
for (Enumeration en = this.headers.propertyNames(); en.hasMoreElements();) {
String key = (String) en.nextElement();
response.addHeader(key, this.headers.getProperty(key));
}
}
/**
* Determine the <code>JasperReport</code> to fill.
* Called by {@link #fillReport}.
* <p>The default implementation returns the report as statically configured
* through the 'url' property (and loaded by {@link #loadReport()}).
* Can be overridden in subclasses in order to dynamically obtain a
* <code>JasperReport</code> instance. As an alternative, consider
* overriding the {@link #fillReport} template method itself.
* @return an instance of <code>JasperReport</code>
*/
protected JasperReport getReport() {
return this.report;
}
/**
* Create an appropriate <code>JRDataSource</code> for passed-in report data.
* Called by {@link #fillReport} when its own lookup steps were not successful.
* <p>The default implementation looks for a value of type <code>java.util.Collection</code>
* or object array (in that order). Can be overridden in subclasses.
* @param model the model map, as passed in for view rendering
* @return the <code>JRDataSource</code> or <code>null</code> if the data source is not found
* @see #getReportDataTypes
* @see #convertReportData
*/
protected JRDataSource getReportData(Map<String, Object> model) {
// Try to find matching attribute, of given prioritized types.
Object value = CollectionUtils.findValueOfType(model.values(), getReportDataTypes());
return (value != null ? convertReportData(value) : null);
}
/**
* Convert the given report data value to a <code>JRDataSource</code>.
* <p>The default implementation delegates to <code>JasperReportUtils</code> unless
* the report data value is an instance of <code>JRDataSourceProvider</code>.
* A <code>JRDataSource</code>, <code>JRDataSourceProvider</code>,
* <code>java.util.Collection</code> or object array is detected.
* <code>JRDataSource</code>s are returned as is, whilst <code>JRDataSourceProvider</code>s
* are used to create an instance of <code>JRDataSource</code> which is then returned.
* The latter two are converted to <code>JRBeanCollectionDataSource</code> or
* <code>JRBeanArrayDataSource</code>, respectively.
* @param value the report data value to convert
* @return the JRDataSource
* @throws IllegalArgumentException if the value could not be converted
* @see org.springframework.ui.jasperreports.JasperReportsUtils#convertReportData
* @see net.sf.jasperreports.engine.JRDataSource
* @see net.sf.jasperreports.engine.JRDataSourceProvider
* @see net.sf.jasperreports.engine.data.JRBeanCollectionDataSource
* @see net.sf.jasperreports.engine.data.JRBeanArrayDataSource
*/
protected JRDataSource convertReportData(Object value) throws IllegalArgumentException {
if (value instanceof JRDataSourceProvider) {
return createReport((JRDataSourceProvider) value);
}
else {
return JasperReportsUtils.convertReportData(value);
}
}
/**
* Create a report using the given provider.
* @param provider the JRDataSourceProvider to use
* @return the created report
*/
protected JRDataSource createReport(JRDataSourceProvider provider) {
try {
JasperReport report = getReport();
if (report == null) {
throw new IllegalStateException("No main report defined for JRDataSourceProvider - " +
"specify a 'url' on this view or override 'getReport()'");
}
return provider.create(report);
}
catch (JRException ex) {
throw new IllegalArgumentException("Supplied JRDataSourceProvider is invalid", ex);
}
}
/**
* Return the value types that can be converted to a <code>JRDataSource</code>,
* in prioritized order. Should only return types that the
* {@link #convertReportData} method is actually able to convert.
* <p>Default value types are: <code>java.util.Collection</code> and <code>Object</code> array.
* @return the value types in prioritized order
*/
protected Class[] getReportDataTypes() {
return new Class[] {Collection.class, Object[].class};
}
/**
* Template method to be overridden for custom post-processing of the
* populated report. Invoked after filling but before rendering.
* <p>The default implementation is empty.
* @param populatedReport the populated <code>JasperPrint</code>
* @param model the map containing report parameters
* @throws Exception if post-processing failed
*/
protected void postProcessReport(JasperPrint populatedReport, Map<String, Object> model) throws Exception {
}
/**
* Subclasses should implement this method to perform the actual rendering process.
* <p>Note that the content type has not been set yet: Implementors should build
* a content type String and set it via <code>response.setContentType</code>.
* If necessary, this can include a charset clause for a specific encoding.
* The latter will only be necessary for textual output onto a Writer, and only
* in case of the encoding being specified in the JasperReports exporter parameters.
* <p><b>WARNING:</b> Implementors should not use <code>response.setCharacterEncoding</code>
* unless they are willing to depend on Servlet API 2.4 or higher. Prefer a
* concatenated content type String with a charset clause instead.
* @param populatedReport the populated <code>JasperPrint</code> to render
* @param model the map containing report parameters
* @param response the HTTP response the report should be rendered to
* @throws Exception if rendering failed
* @see #getContentType()
* @see javax.servlet.ServletResponse#setContentType
* @see javax.servlet.ServletResponse#setCharacterEncoding
*/
protected abstract void renderReport(
JasperPrint populatedReport, Map<String, Object> model, HttpServletResponse response)
throws Exception;
}
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