gwtuploadsample.server.SampleUploadServlet.java Source code

Introduction

Here is the source code for gwtuploadsample.server.SampleUploadServlet.java

Source

/*
 * Copyright 2010 Manuel Carrasco Moino. (manolo at apache/org)
 * http://code.google.com/p/gwtupload
 *
 * 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 gwtuploadsample.server;

import static gwtupload.shared.UConsts.*;
import gwtupload.server.UploadAction;
import gwtupload.server.exceptions.UploadActionException;

import org.apache.commons.fileupload.FileItem;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Hashtable;
import java.util.List;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * This is an example of how to use UploadAction class.
 *
 * This servlet saves all received files in a temporary folder,
 * and deletes them when the user sends a remove request.
 *
 * @author Manolo Carrasco Moino
 *
 */
public class SampleUploadServlet extends UploadAction {

    private static final long serialVersionUID = 1L;

    Hashtable<String, String> receivedContentTypes = new Hashtable<String, String>();
    /**
     * Maintain a list with received files and their content types.
     */
    Hashtable<String, File> receivedFiles = new Hashtable<String, File>();

    /**
     * Override executeAction to save the received files in a custom place
     * and delete this items from session.
     */
    @Override
    public String executeAction(HttpServletRequest request, List<FileItem> sessionFiles)
            throws UploadActionException {
        String response = "";
        int cont = 0;
        for (FileItem item : sessionFiles) {
            if (false == item.isFormField()) {
                cont++;
                try {
                    /// Create a new file based on the remote file name in the client
                    // String saveName = item.getName().replaceAll("[\\\\/><\\|\\s\"'{}()\\[\\]]+", "_");
                    // File file =new File("/tmp/" + saveName);

                    /// Create a temporary file placed in /tmp (only works in unix)
                    // File file = File.createTempFile("upload-", ".bin", new File("/tmp"));

                    /// Create a temporary file placed in the default system temp folder
                    File file = File.createTempFile("upload-", ".bin");
                    item.write(file);

                    /// Save a list with the received files
                    receivedFiles.put(item.getFieldName(), file);
                    receivedContentTypes.put(item.getFieldName(), item.getContentType());

                    /// Compose a xml message with the full file information
                    response += "<file-" + cont + "-field>" + item.getFieldName() + "</file-" + cont + "-field>\n";
                    response += "<file-" + cont + "-name>" + item.getName() + "</file-" + cont + "-name>\n";
                    response += "<file-" + cont + "-size>" + item.getSize() + "</file-" + cont + "-size>\n";
                    response += "<file-" + cont + "-type>" + item.getContentType() + "</file-" + cont + "type>\n";
                } catch (Exception e) {
                    throw new UploadActionException(e);
                }
            }
        }

        /// Remove files from session because we have a copy of them
        removeSessionFileItems(request);

        /// Send information of the received files to the client.
        return "<response>\n" + response + "</response>\n";
    }

    /**
     * Get the content of an uploaded file.
     */
    @Override
    public void getUploadedFile(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String fieldName = request.getParameter(PARAM_SHOW);
        File f = receivedFiles.get(fieldName);
        if (f != null) {
            response.setContentType(receivedContentTypes.get(fieldName));
            FileInputStream is = new FileInputStream(f);
            copyFromInputStreamToOutputStream(is, response.getOutputStream());
        } else {
            super.getUploadedFile(request, response);
        }
    }

    /**
     * Remove a file when the user sends a delete request.
     */
    @Override
    public void removeItem(HttpServletRequest request, String fieldName) throws UploadActionException {
        File file = receivedFiles.get(fieldName);
        receivedFiles.remove(fieldName);
        receivedContentTypes.remove(fieldName);
        if (file != null) {
            file.delete();
            logger.info(
                    "SAMPLE-SERVLET (" + request.getSession().getId() + ") removed file " + file.getAbsolutePath());
        }
    }
}