Java tutorial
package bijian.util.upload; /* * $Id: JakartaMultiPartRequest.java 932009 2010-04-08 17:01:16Z lukaszlenart $ * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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 com.opensymphony.xwork2.inject.Inject; import org.apache.commons.fileupload.FileItem; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.RequestContext; import org.apache.commons.fileupload.disk.DiskFileItem; import org.apache.commons.fileupload.disk.DiskFileItemFactory; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.struts2.StrutsConstants; import org.apache.struts2.dispatcher.multipart.MultiPartRequest; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import javax.servlet.http.HttpServletRequest; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import java.util.ArrayList; import java.util.Collections; import java.util.Enumeration; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Multipart form data request adapter for Jakarta Commons Fileupload package. */ public class MyMultiPartRequest implements MultiPartRequest { static final Logger LOG = LoggerFactory.getLogger(MultiPartRequest.class); // maps parameter name -> List of FileItem objects protected Map<String, List<FileItem>> files = new HashMap<String, List<FileItem>>(); // maps parameter name -> List of param values protected Map<String, List<String>> params = new HashMap<String, List<String>>(); // any errors while processing this request protected List<String> errors = new ArrayList<String>(); protected long maxSize; @Inject(StrutsConstants.STRUTS_MULTIPART_MAXSIZE) public void setMaxSize(String maxSize) { this.maxSize = Long.parseLong(maxSize); } /** * Creates a new request wrapper to handle multi-part data using methods adapted from Jason Pell's * multipart classes (see class description). * * @param saveDir the directory to save off the file * @param request the request containing the multipart * @throws java.io.IOException is thrown if encoding fails. */ public void parse(HttpServletRequest request, String saveDir) throws IOException { try { processUpload(request, saveDir); } catch (FileUploadException e) { LOG.warn("Unable to parse request", e); errors.add(e.getMessage()); } } private void processUpload(HttpServletRequest request, String saveDir) throws FileUploadException, UnsupportedEncodingException { for (FileItem item : parseRequest(request, saveDir)) { if (LOG.isDebugEnabled()) { LOG.debug("Found item " + item.getFieldName()); } if (item.isFormField()) { processNormalFormField(item, request.getCharacterEncoding()); } else { processFileField(item); } } } private void processFileField(FileItem item) { LOG.debug("Item is a file upload"); // Skip file uploads that don't have a file name - meaning that no file was selected. if (item.getName() == null || item.getName().trim().length() < 1) { LOG.debug("No file has been uploaded for the field: " + item.getFieldName()); return; } List<FileItem> values; if (files.get(item.getFieldName()) != null) { values = files.get(item.getFieldName()); } else { values = new ArrayList<FileItem>(); } values.add(item); files.put(item.getFieldName(), values); } private void processNormalFormField(FileItem item, String charset) throws UnsupportedEncodingException { LOG.debug("Item is a normal form field"); List<String> values; if (params.get(item.getFieldName()) != null) { values = params.get(item.getFieldName()); } else { values = new ArrayList<String>(); } // note: see http://jira.opensymphony.com/browse/WW-633 // basically, in some cases the charset may be null, so // we're just going to try to "other" method (no idea if this // will work) if (charset != null) { values.add(item.getString(charset)); } else { values.add(item.getString()); } params.put(item.getFieldName(), values); } private List<FileItem> parseRequest(HttpServletRequest servletRequest, String saveDir) throws FileUploadException { DiskFileItemFactory fac = createDiskFileItemFactory(saveDir); ServletFileUpload upload = new ServletFileUpload(fac); upload.setSizeMax(maxSize); FileUploadListener myFileUploadListener = new FileUploadListener(servletRequest); upload.setProgressListener(myFileUploadListener); return upload.parseRequest(createRequestContext(servletRequest)); } private DiskFileItemFactory createDiskFileItemFactory(String saveDir) { DiskFileItemFactory fac = new DiskFileItemFactory(); // Make sure that the data is written to file fac.setSizeThreshold(0); if (saveDir != null) { fac.setRepository(new File(saveDir)); } return fac; } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileParameterNames() */ public Enumeration<String> getFileParameterNames() { return Collections.enumeration(files.keySet()); } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getContentType(java.lang.String) */ public String[] getContentType(String fieldName) { List<FileItem> items = files.get(fieldName); if (items == null) { return null; } List<String> contentTypes = new ArrayList<String>(items.size()); for (FileItem fileItem : items) { contentTypes.add(fileItem.getContentType()); } return contentTypes.toArray(new String[contentTypes.size()]); } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFile(java.lang.String) */ public File[] getFile(String fieldName) { List<FileItem> items = files.get(fieldName); if (items == null) { return null; } List<File> fileList = new ArrayList<File>(items.size()); for (FileItem fileItem : items) { fileList.add(((DiskFileItem) fileItem).getStoreLocation()); } return fileList.toArray(new File[fileList.size()]); } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileNames(java.lang.String) */ public String[] getFileNames(String fieldName) { List<FileItem> items = files.get(fieldName); if (items == null) { return null; } List<String> fileNames = new ArrayList<String>(items.size()); for (FileItem fileItem : items) { fileNames.add(getCanonicalName(fileItem.getName())); } return fileNames.toArray(new String[fileNames.size()]); } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFilesystemName(java.lang.String) */ public String[] getFilesystemName(String fieldName) { List<FileItem> items = files.get(fieldName); if (items == null) { return null; } List<String> fileNames = new ArrayList<String>(items.size()); for (FileItem fileItem : items) { fileNames.add(((DiskFileItem) fileItem).getStoreLocation().getName()); } return fileNames.toArray(new String[fileNames.size()]); } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameter(java.lang.String) */ public String getParameter(String name) { List<String> v = params.get(name); if (v != null && v.size() > 0) { return v.get(0); } return null; } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterNames() */ public Enumeration<String> getParameterNames() { return Collections.enumeration(params.keySet()); } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterValues(java.lang.String) */ public String[] getParameterValues(String name) { List<String> v = params.get(name); if (v != null && v.size() > 0) { return v.toArray(new String[v.size()]); } return null; } /* (non-Javadoc) * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getErrors() */ public List getErrors() { return errors; } /** * Returns the canonical name of the given file. * * @param filename the given file * @return the canonical name of the given file */ private String getCanonicalName(String filename) { int forwardSlash = filename.lastIndexOf("/"); int backwardSlash = filename.lastIndexOf("\\"); if (forwardSlash != -1 && forwardSlash > backwardSlash) { filename = filename.substring(forwardSlash + 1, filename.length()); } else if (backwardSlash != -1 && backwardSlash >= forwardSlash) { filename = filename.substring(backwardSlash + 1, filename.length()); } return filename; } /** * Creates a RequestContext needed by Jakarta Commons Upload. * * @param req the request. * @return a new request context. */ private RequestContext createRequestContext(final HttpServletRequest req) { return new RequestContext() { public String getCharacterEncoding() { return req.getCharacterEncoding(); } public String getContentType() { return req.getContentType(); } public int getContentLength() { return req.getContentLength(); } public InputStream getInputStream() throws IOException { InputStream in = req.getInputStream(); if (in == null) { throw new IOException("Missing content in the request"); } return req.getInputStream(); } }; } }