<%@page pageEncoding="UTF-8" import="java.io.*"%> <%@include file="UploadRequest.jsp"%> <%! public static class UploadException extends Exception { private static final long serialVersionUID = 579958777177500819L; public UploadException(String msg) { super(msg); } } public static class Upload { /** * 接受上传 * * @param uRequest * 上传 POJO * @return * @throws UploadException */ public UploadRequest upload(UploadRequest uRequest) throws UploadException { HttpServletRequest req = uRequest.getRequest(); // 取得客户端上传的数据类型 String contentType = req.getContentType(); if(!req.getMethod().equals("POST")){ throw new UploadException("必须 POST 请求"); } if (contentType.indexOf("multipart/form-data") == -1) { throw new UploadException("未设置表单 multipart/form-data"); } int formDataLength = req.getContentLength(); if (formDataLength > uRequest.getMaxFileSize()) { // 是否超大 throw new UploadException("文件大小超过系统限制！"); } // 保存上传的文件数据 byte dateBytes[] = new byte[formDataLength]; int byteRead = 0, totalRead = 0; try(DataInputStream in = new DataInputStream(req.getInputStream());){ while (totalRead < formDataLength) { byteRead = in.read(dateBytes, totalRead, formDataLength); totalRead += byteRead; } } catch (IOException e) { e.printStackTrace(); throw new UploadException(e.toString()); } // 取得数据分割字符串 int lastIndex = contentType.lastIndexOf("="); // 数据分割线开始位置boundary=--------------------------- String boundary = contentType.substring(lastIndex + 1, contentType.length());// ---------------------------257261863525035 // 计算开头数据头占用的长度 int startPos = getStartPos(dateBytes); // 边界位置 int endPos = byteIndexOf(dateBytes, boundary.getBytes(), (dateBytes.length - startPos)) - 4; // 创建文件 String fileName = uRequest.getUpload_save_folder() + getFileName(dateBytes, uRequest.isNewName()); uRequest.setUploaded_save_fileName(fileName); File checkedFile = initFile(uRequest); // 写入文件 try(FileOutputStream fileOut = new FileOutputStream(checkedFile);){ fileOut.write(dateBytes, startPos, endPos - startPos); fileOut.flush(); uRequest.setOk(true); } catch (FileNotFoundException e) { e.printStackTrace(); throw new UploadException(e.toString()); } catch (IOException e) { e.printStackTrace(); throw new UploadException(e.toString()); } return uRequest; } } /** * 获取开头数据头占用的长度 * * @param dateBytes * 文件二进制数据 * @return */ private static int getStartPos(byte[] dateBytes) { int startPos; startPos = byteIndexOf(dateBytes, "filename=\"".getBytes(), 0); startPos = byteIndexOf(dateBytes, "\n".getBytes(), startPos) + 1; // 遍历掉3个换行符到数据块 startPos = byteIndexOf(dateBytes, "\n".getBytes(), startPos) + 1; startPos = byteIndexOf(dateBytes, "\n".getBytes(), startPos) + 1; return startPos; } /** * 在字节数组里查找某个字节数组，找到返回>=0，未找到返回-1 * @param data * @param search * @param start * @return */ private static int byteIndexOf(byte[] data, byte[] search, int start) { int index = -1; int len = search.length; for (int i = start, j = 0; i < data.length; i++) { int temp = i; j = 0; while (data[temp] == search[j]) { // System.out.println((j+1)+",值："+data[temp]+","+search[j]); // 计数 j++; temp++; if (j == len) { index = i; return index; } } } return index; } /** * 如果没有指定目录则创建；检测是否可以覆盖文件 * * @param uRequest * 上传 POJO * @return * @throws UploadException */ private static File initFile(UploadRequest uRequest) throws UploadException { File dir = new File(uRequest.getUpload_save_folder()); if (!dir.exists()) dir.mkdirs(); File checkFile = new File(uRequest.getUploaded_save_fileName()); if (!uRequest.isFileOverwrite() && checkFile.exists()) { throw new UploadException("文件已经存在，禁止覆盖！"); } return checkFile; } /** * 获取 POST Body 中的文件名 * * @param dateBytes * 文件二进制数据 * @param isAutoName * 是否自定命名，true = 时间戳文件名 * @return */ private static String getFileName(byte[] dateBytes, boolean isAutoName) { String saveFile = null; if(isAutoName){ saveFile = "2016" + System.currentTimeMillis(); } else { String data = null; try { data = new String(dateBytes, "UTF-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); data = "errFileName"; } // 取得上传的文件名 saveFile = data.substring(data.indexOf("filename=\"") + 10); saveFile = saveFile.substring(0, saveFile.indexOf("\n")); saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1, saveFile.indexOf("\"")); } return saveFile; } %>
通过 DataInputStream 读取流数据到 dataBytes 中然后写入 FileOutputStream。另外还有些围绕配置的逻辑。