Java tutorial
package net.dkahn.web.controller; /* * $Id: CommonsMultipartRequestHandler.java 54929 2004-10-16 16:38:42Z germuska $ * * Copyright 1999-2004 The Apache Software Foundation. * * 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. */ import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.io.Serializable; import java.util.Hashtable; import java.util.Iterator; import java.util.List; import javax.servlet.ServletContext; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import net.dkahn.web.listener.UploadListener; import net.dkahn.web.monitored.MonitoredDiskFileItemFactory; import org.apache.commons.fileupload.DiskFileUpload; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileItemFactory; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.struts.Globals; import org.apache.struts.action.ActionMapping; import org.apache.struts.action.ActionServlet; import org.apache.struts.config.ModuleConfig; import org.apache.struts.upload.CommonsMultipartRequestHandler; import org.apache.struts.upload.FormFile; import org.apache.struts.upload.MultipartRequestHandler; import org.apache.struts.upload.MultipartRequestWrapper; /** * This class implements the <code>MultipartRequestHandler</code> interface * by providing a wrapper around the Jakarta Commons FileUpload library. * * @version $Rev: 54929 $ $Date: 2004-10-16 17:38:42 +0100 (Sat, 16 Oct 2004) $ * @since Struts 1.1 */ public class ExtendedMultiPartRequestHandler implements MultipartRequestHandler { // ----------------------------------------------------- Manifest Constants /** * The default value for the maximum allowable size, in bytes, of an * uploaded file. The value is equivalent to 250MB. */ public static final long DEFAULT_SIZE_MAX = 250 * 1024 * 1024; /** * The default value for the threshold which determines whether an uploaded * file will be written to disk or cached in memory. The value is equivalent * to 250KB. */ public static final int DEFAULT_SIZE_THRESHOLD = 256 * 1024; // ----------------------------------------------------- Instance Variables /** * Commons Logging instance. */ protected static Log log = LogFactory.getLog(CommonsMultipartRequestHandler.class); /** * The combined text and file request parameters. */ private Hashtable elementsAll; /** * The file request parameters. */ private Hashtable elementsFile; /** * The text request parameters. */ private Hashtable elementsText; /** * The action mapping with which this handler is associated. */ private ActionMapping mapping; /** * The servlet with which this handler is associated. */ private ActionServlet servlet; // ---------------------------------------- MultipartRequestHandler Methods /** * Retrieves the servlet with which this handler is associated. * * @return The associated servlet. */ public ActionServlet getServlet() { return this.servlet; } /** * Sets the servlet with which this handler is associated. * * @param servlet The associated servlet. */ public void setServlet(ActionServlet servlet) { this.servlet = servlet; } /** * Retrieves the action mapping with which this handler is associated. * * @return The associated action mapping. */ public ActionMapping getMapping() { return this.mapping; } /** * Sets the action mapping with which this handler is associated. * * @param mapping The associated action mapping. */ public void setMapping(ActionMapping mapping) { this.mapping = mapping; } /** * Parses the input stream and partitions the parsed items into a set of * form fields and a set of file items. In the process, the parsed items * are translated from Commons FileUpload <code>FileItem</code> instances * to Struts <code>FormFile</code> instances. * * @param request The multipart request to be processed. * * @throws ServletException if an unrecoverable error occurs. */ public void handleRequest(HttpServletRequest request) throws ServletException { // Get the app config for the current request. ModuleConfig ac = (ModuleConfig) request.getAttribute(Globals.MODULE_KEY); //---------------------------------------------------------- // Changed this section of code, that is it. //----------------------------------------------------------- log.debug("Handling the request.."); UploadListener listener = new UploadListener(request, 1); log.debug("uploading file with optional monitoring.."); // Create a factory for disk-based file items FileItemFactory factory = new MonitoredDiskFileItemFactory(listener); log.debug("got the factory now get the ServletFileUpload"); ServletFileUpload upload = new ServletFileUpload(factory); log.debug("Should have the ServletFileUpload by now."); // The following line is to support an "EncodingFilter" // see http://nagoya.apache.org/bugzilla/show_bug.cgi?id=23255 upload.setHeaderEncoding(request.getCharacterEncoding()); // Set the maximum size before a FileUploadException will be thrown. upload.setSizeMax(getSizeMax(ac)); //---------------------------------------------------------------- // Create the hash tables to be populated. elementsText = new Hashtable(); elementsFile = new Hashtable(); elementsAll = new Hashtable(); // Parse the request into file items. List items = null; try { items = upload.parseRequest(request); } catch (DiskFileUpload.SizeLimitExceededException e) { // Special handling for uploads that are too big. request.setAttribute(MultipartRequestHandler.ATTRIBUTE_MAX_LENGTH_EXCEEDED, Boolean.TRUE); return; } catch (FileUploadException e) { log.error("Failed to parse multipart request", e); throw new ServletException(e); } // Partition the items into form fields and files. Iterator iter = items.iterator(); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); if (item.isFormField()) { addTextParameter(request, item); } else { addFileParameter(item); } } } /** * Returns a hash table containing the text (that is, non-file) request * parameters. * * @return The text request parameters. */ public Hashtable getTextElements() { return this.elementsText; } /** * Returns a hash table containing the file (that is, non-text) request * parameters. * * @return The file request parameters. */ public Hashtable getFileElements() { return this.elementsFile; } /** * Returns a hash table containing both text and file request parameters. * * @return The text and file request parameters. */ public Hashtable getAllElements() { return this.elementsAll; } /** * Cleans up when a problem occurs during request processing. */ public void rollback() { Iterator iter = elementsFile.values().iterator(); while (iter.hasNext()) { FormFile formFile = (FormFile) iter.next(); formFile.destroy(); } } /** * Cleans up at the end of a request. */ public void finish() { rollback(); } // -------------------------------------------------------- Support Methods /** * Returns the maximum allowable size, in bytes, of an uploaded file. The * value is obtained from the current module's controller configuration. * * @param mc The current module's configuration. * * @return The maximum allowable file size, in bytes. */ protected long getSizeMax(ModuleConfig mc) { return convertSizeToBytes(mc.getControllerConfig().getMaxFileSize(), DEFAULT_SIZE_MAX); } /** * Returns the size threshold which determines whether an uploaded file * will be written to disk or cached in memory. * * @param mc The current module's configuration. * * @return The size threshold, in bytes. */ protected long getSizeThreshold(ModuleConfig mc) { return convertSizeToBytes(mc.getControllerConfig().getMemFileSize(), DEFAULT_SIZE_THRESHOLD); } /** * Converts a size value from a string representation to its numeric value. * The string must be of the form nnnm, where nnn is an arbitrary decimal * value, and m is a multiplier. The multiplier must be one of 'K', 'M' and * 'G', representing kilobytes, megabytes and gigabytes respectively. * * If the size value cannot be converted, for example due to invalid syntax, * the supplied default is returned instead. * * @param sizeString The string representation of the size to be converted. * @param defaultSize The value to be returned if the string is invalid. * * @return The actual size in bytes. */ protected long convertSizeToBytes(String sizeString, long defaultSize) { int multiplier = 1; if (sizeString.endsWith("K")) { multiplier = 1024; } else if (sizeString.endsWith("M")) { multiplier = 1024 * 1024; } else if (sizeString.endsWith("G")) { multiplier = 1024 * 1024 * 1024; } if (multiplier != 1) { sizeString = sizeString.substring(0, sizeString.length() - 1); } long size = 0; try { size = Long.parseLong(sizeString); } catch (NumberFormatException nfe) { log.warn("Invalid format for file size ('" + sizeString + "'). Using default."); size = defaultSize; multiplier = 1; } return (size * multiplier); } /** * Returns the path to the temporary directory to be used for uploaded * files which are written to disk. The directory used is determined from * the first of the following to be non-empty. * <ol> * <li>A temp dir explicitly defined either using the <code>tempDir</code> * servlet init param, or the <code>tempDir</code> attribute of the * <controller> element in the Struts config file.</li> * <li>The container-specified temp dir, obtained from the * <code>javax.servlet.context.tempdir</code> servlet context * attribute.</li> * <li>The temp dir specified by the <code>java.io.tmpdir</code> system * property.</li> * (/ol> * * @param mc The module config instance for which the path should be * determined. * * @return The path to the directory to be used to store uploaded files. */ protected String getRepositoryPath(ModuleConfig mc) { // First, look for an explicitly defined temp dir. String tempDir = mc.getControllerConfig().getTempDir(); // If none, look for a container specified temp dir. if (tempDir == null || tempDir.length() == 0) { if (servlet != null) { ServletContext context = servlet.getServletContext(); File tempDirFile = (File) context.getAttribute("javax.servlet.context.tempdir"); tempDir = tempDirFile.getAbsolutePath(); } // If none, pick up the system temp dir. if (tempDir == null || tempDir.length() == 0) { tempDir = System.getProperty("java.io.tmpdir"); } } if (log.isTraceEnabled()) { log.trace("File upload temp dir: " + tempDir); } return tempDir; } /** * Adds a regular text parameter to the set of text parameters for this * request and also to the list of all parameters. Handles the case of * multiple values for the same parameter by using an array for the * parameter value. * * @param request The request in which the parameter was specified. * @param item The file item for the parameter to add. */ protected void addTextParameter(HttpServletRequest request, FileItem item) { String name = item.getFieldName(); String value = null; boolean haveValue = false; String encoding = request.getCharacterEncoding(); if (encoding != null) { try { value = item.getString(encoding); haveValue = true; } catch (Exception e) { // Handled below, since haveValue is false. } } if (!haveValue) { try { value = item.getString("ISO-8859-1"); } catch (java.io.UnsupportedEncodingException uee) { value = item.getString(); } haveValue = true; } if (request instanceof MultipartRequestWrapper) { MultipartRequestWrapper wrapper = (MultipartRequestWrapper) request; wrapper.setParameter(name, value); } String[] oldArray = (String[]) elementsText.get(name); String[] newArray; if (oldArray != null) { newArray = new String[oldArray.length + 1]; System.arraycopy(oldArray, 0, newArray, 0, oldArray.length); newArray[oldArray.length] = value; } else { newArray = new String[] { value }; } elementsText.put(name, newArray); elementsAll.put(name, newArray); } /** * Adds a file parameter to the set of file parameters for this request * and also to the list of all parameters. * * @param item The file item for the parameter to add. */ protected void addFileParameter(FileItem item) { FormFile formFile = new CommonsFormFile(item); elementsFile.put(item.getFieldName(), formFile); elementsAll.put(item.getFieldName(), formFile); } // ---------------------------------------------------------- Inner Classes /** * This class implements the Struts <code>FormFile</code> interface by * wrapping the Commons FileUpload <code>FileItem</code> interface. This * implementation is <i>read-only</i>; any attempt to modify an instance * of this class will result in an <code>UnsupportedOperationException</code>. */ static class CommonsFormFile implements FormFile, Serializable { /** * The <code>FileItem</code> instance wrapped by this object. */ FileItem fileItem; /** * Constructs an instance of this class which wraps the supplied * file item. * * @param fileItem The Commons file item to be wrapped. */ public CommonsFormFile(FileItem fileItem) { this.fileItem = fileItem; } /** * Returns the content type for this file. * * @return A String representing content type. */ public String getContentType() { return fileItem.getContentType(); } /** * Sets the content type for this file. * <p> * NOTE: This method is not supported in this implementation. * * @param contentType A string representing the content type. */ public void setContentType(String contentType) { throw new UnsupportedOperationException("The setContentType() method is not supported."); } /** * Returns the size, in bytes, of this file. * * @return The size of the file, in bytes. */ public int getFileSize() { return (int) fileItem.getSize(); } /** * Sets the size, in bytes, for this file. * <p> * NOTE: This method is not supported in this implementation. * * @param filesize The size of the file, in bytes. */ public void setFileSize(int filesize) { throw new UnsupportedOperationException("The setFileSize() method is not supported."); } /** * Returns the (client-side) file name for this file. * * @return The client-size file name. */ public String getFileName() { return getBaseFileName(fileItem.getName()); } /** * Sets the (client-side) file name for this file. * <p> * NOTE: This method is not supported in this implementation. * * @param fileName The client-side name for the file. */ public void setFileName(String fileName) { throw new UnsupportedOperationException("The setFileName() method is not supported."); } /** * Returns the data for this file as a byte array. Note that this may * result in excessive memory usage for large uploads. The use of the * {@link #getInputStream() getInputStream} method is encouraged * as an alternative. * * @return An array of bytes representing the data contained in this * form file. * * @exception java.io.FileNotFoundException If some sort of file representation * cannot be found for the FormFile * @exception java.io.IOException If there is some sort of IOException */ public byte[] getFileData() throws FileNotFoundException, IOException { return fileItem.get(); } /** * Get an InputStream that represents this file. This is the preferred * method of getting file data. * @exception java.io.FileNotFoundException If some sort of file representation * cannot be found for the FormFile * @exception java.io.IOException If there is some sort of IOException */ public InputStream getInputStream() throws FileNotFoundException, IOException { return fileItem.getInputStream(); } /** * Destroy all content for this form file. * Implementations should remove any temporary * files or any temporary file data stored somewhere */ public void destroy() { fileItem.delete(); } /** * Returns the base file name from the supplied file path. On the surface, * this would appear to be a trivial task. Apparently, however, some Linux * JDKs do not implement <code>File.getName()</code> correctly for Windows * paths, so we attempt to take care of that here. * * @param filePath The full path to the file. * * @return The base file name, from the end of the path. */ protected String getBaseFileName(String filePath) { // First, ask the JDK for the base file name. String fileName = new File(filePath).getName(); // Now check for a Windows file name parsed incorrectly. int colonIndex = fileName.indexOf(":"); if (colonIndex == -1) { // Check for a Windows SMB file path. colonIndex = fileName.indexOf("\\\\"); } int backslashIndex = fileName.lastIndexOf("\\"); if (colonIndex > -1 && backslashIndex > -1) { // Consider this filename to be a full Windows path, and parse it // accordingly to retrieve just the base file name. fileName = fileName.substring(backslashIndex + 1); } return fileName; } /** * Returns the (client-side) file name for this file. * * @return The client-size file name. */ public String toString() { return getFileName(); } } }