org.springframework.web.servlet.view.document.AbstractXlsView Maven / Gradle / Ivy
/*
* Copyright 2002-2017 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.web.servlet.view.document;
import java.io.IOException;
import java.util.Map;
import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.web.servlet.view.AbstractView;
/**
* Convenient superclass for Excel document views in traditional XLS format.
* Compatible with Apache POI 3.5 and higher.
*
* For working with the workbook in the subclass, see
* Apache's POI site
*
* @author Juergen Hoeller
* @since 4.2
*/
public abstract class AbstractXlsView extends AbstractView {
/**
* Default Constructor.
* Sets the content type of the view to "application/vnd.ms-excel".
*/
public AbstractXlsView() {
setContentType("application/vnd.ms-excel");
}
@Override
protected boolean generatesDownloadContent() {
return true;
}
/**
* Renders the Excel view, given the specified model.
*/
@Override
protected final void renderMergedOutputModel(
Map model, HttpServletRequest request, HttpServletResponse response) throws Exception {
// Create a fresh workbook instance for this render step.
Workbook workbook = createWorkbook(model, request);
// Delegate to application-provided document code.
buildExcelDocument(model, workbook, request, response);
// Set the content type.
response.setContentType(getContentType());
// Flush byte array to servlet output stream.
renderWorkbook(workbook, response);
}
/**
* Template method for creating the POI {@link Workbook} instance.
* The default implementation creates a traditional {@link HSSFWorkbook}.
* Spring-provided subclasses are overriding this for the OOXML-based variants;
* custom subclasses may override this for reading a workbook from a file.
* @param model the model Map
* @param request current HTTP request (for taking the URL or headers into account)
* @return the new {@link Workbook} instance
*/
protected Workbook createWorkbook(Map model, HttpServletRequest request) {
return new HSSFWorkbook();
}
/**
* The actual render step: taking the POI {@link Workbook} and rendering
* it to the given response.
* @param workbook the POI Workbook to render
* @param response current HTTP response
* @throws IOException when thrown by I/O methods that we're delegating to
*/
protected void renderWorkbook(Workbook workbook, HttpServletResponse response) throws IOException {
ServletOutputStream out = response.getOutputStream();
workbook.write(out);
workbook.close();
}
/**
* Application-provided subclasses must implement this method to populate
* the Excel workbook document, given the model.
* @param model the model Map
* @param workbook the Excel workbook to populate
* @param request in case we need locale etc. Shouldn't look at attributes.
* @param response in case we need to set cookies. Shouldn't write to it.
*/
protected abstract void buildExcelDocument(
Map model, Workbook workbook, HttpServletRequest request, HttpServletResponse response)
throws Exception;
}