servlet方式完美实现文件上传

package com.wen.decorator; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import org.apache.commons.fileupload.FileItemIterator; import org.apache.commons.fileupload.FileItemStream; import org.apache.commons.fileupload.FileUploadException; import org.apache.commons.fileupload.servlet.ServletFileUpload; import org.apache.commons.fileupload.util.Streams; public class MultipartWrapper extends HttpServletRequestWrapper { private Map<String, String[]> params = new HashMap<String, String[]>(); // private final static String PATH = // "C:\\Users\\John_wen\\Workspaces\\MyEclipse 10\\FileUpload\\WebRoot\\upload\\"; public MultipartWrapper(HttpServletRequest request) throws FileUploadException, IOException { super(request); setParams(request); } private void setParams(HttpServletRequest request) throws FileUploadException, IOException { boolean isMul = ServletFileUpload.isMultipartContent(request); if (isMul) {// 如果为true表示是文件上传 ServletFileUpload upload = new ServletFileUpload(); FileItemIterator fileItemIterator = upload.getItemIterator(request); InputStream is = null; while (fileItemIterator.hasNext()) { FileItemStream fis = fileItemIterator.next(); is = fis.openStream(); if (fis.isFormField()) { setFormField(fis.getFieldName(), is); } else { if (fis.getName() != null && !"".equals(fis.getName())) { String path = request.getSession().getServletContext().getRealPath("/upload"); // 表示文件，上传操作 Streams.copy(is, new FileOutputStream(path + "\\" + fis.getName()), true); } params.put(fis.getFieldName(), new String[] { fis.getName() }); } } } else {// 正常流程 params = request.getParameterMap(); } } private void setFormField(String fieldName, InputStream is) throws IOException { // 先取出params中对应的fieldName的值； String[] values = params.get(fieldName); if (params.containsKey(fieldName)) { // 如果包含有key values = Arrays.copyOf(values, values.length + 1); values[values.length - 1] = Streams.asString(is); params.put(fieldName, values); } else { params.put(fieldName, new String[] { Streams.asString(is) }); } } @Override public String getParameter(String name) { String[] values = params.get(name); if (values != null) { return values[0]; } else { return null; } } @Override public Map<String, String[]> getParameterMap() { return params; } @Override public String[] getParameterValues(String name) { String[] values = params.get(name); if (values != null) { return values; } else { return null; } } }