Java tutorial
/* * Copyright 2014-2015 CyberVision, Inc. * * 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.kaaproject.avro.ui.sandbox.services; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import javax.servlet.ServletConfig; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.fileupload.util.Streams; import org.kaaproject.avro.ui.sandbox.services.cache.JsonCacheService; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.context.support.SpringBeanAutowiringSupport; public class FileUploadServlet extends HttpServlet { private static final long serialVersionUID = -1660736020844466375L; private static final String FILE_NAME = "fileName"; private static final String JSON_KEY = "jsonKey"; /** The Constant logger. */ private static final Logger logger = LoggerFactory.getLogger(FileUploadServlet.class); @Autowired private JsonCacheService jsonCacheService; @Override public void init(ServletConfig config) throws ServletException { super.init(config); SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this, config.getServletContext()); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ServletFileUpload upload = new ServletFileUpload(); try { FileItemIterator iterator = upload.getItemIterator(request); if (iterator.hasNext()) { FileItemStream item = iterator.next(); String name = item.getFieldName(); logger.debug("Uploading file '{}' with item name '{}'", item.getName(), name); InputStream stream = item.openStream(); ByteArrayOutputStream out = new ByteArrayOutputStream(); Streams.copy(stream, out, true); byte[] data = out.toByteArray(); response.setStatus(HttpServletResponse.SC_OK); response.setContentType("text/html"); response.setCharacterEncoding("utf-8"); response.getWriter().print(new String(data)); response.flushBuffer(); } else { logger.error("No file found in post request!"); throw new RuntimeException("No file found in post request!"); } } catch (Exception e) { logger.error("Unexpected error in FileUploadServlet.doPost: ", e); throw new RuntimeException(e); } } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String jsonKey = request.getParameter(JSON_KEY); String fileName = request.getParameter(FILE_NAME); if (jsonKey != null && fileName != null) { try (OutputStream os = response.getOutputStream()) { response.setContentType("application/json"); response.setHeader("Content-Disposition", "attachment;filename=" + fileName); byte[] content = jsonCacheService.getJson(jsonKey).getBytes(); os.write(content, 0, content.length); logger.debug("Returning text file with name '{}'", fileName); response.flushBuffer(); } catch (IOException e) { logger.error("Unexpected error in FileUploadServlet.doGet: ", e); throw new RuntimeException(e); } } else { logger.error("Empty parameter with file content in get file request!"); throw new RuntimeException("Empty parameter with file content in get file request!"); } } }