近日在试用jcifs_1.3.8 实现Java直接读取局域网内共享文件，其实现就像Linux下的SMB协议，感觉挺方便的~ 可是在实现文件下载时发生了一个奇怪的情况：Txt文件可以正常下载，但是多会了几行空行在前面，而其他文件（如Excle）等则会损坏，结果发现是JSP中换行的问题，现在把实验贴上来以防忘记，顺便与大家分享 ^^ 1. 下载 jcifs-1.3.8.jar 2. 测试JSP：
<%@ page language="java" pageEncoding="UTF-8" contentType="text/html; charset=UTF-8" import="jcifs.smb.*,java.io.*,java.util.*, java.net.URLEncoder,java.net.URLDecoder" %><%! // --------不能有空行 public java.util.List getFileList(String url){ try { SmbFile sf = new SmbFile(url); if(sf!=null){ /*// 仅过滤文件 SmbFile[] files = sf.listFiles(new SmbFilenameFilter(){ public boolean accept(SmbFile dir, String name) throws SmbException { return name.endsWith(".txt"); } }); */ SmbFile[] files = sf.listFiles(); if (files != null) { java.util.List list = new ArrayList(); for (int i = 0; i < files.length; i++){ Map map = new HashMap(); map.put("name", URLEncoder.encode(files[i].getName(),"UTF-8")); map.put("recordurlall", URLEncoder.encode(files[i].getURL().toString(),"UTF-8")); list.add(map); } return list; } } } catch (Exception e) { e.printStackTrace(); } return null; } public byte[] getFile(String url){ SmbFileInputStream in = null; try { ByteArrayOutputStream out = new ByteArrayOutputStream(); in = new SmbFileInputStream(url); // 建立smb文件輸入流 byte buffer[] = new byte[4096]; for(int n = 0; (n = in.read(buffer))>0;){ out.write(buffer, 0, n); } return out.toByteArray(); } catch (Exception e) { e.printStackTrace(); } finally{ try { if (in != null) in.close(); } catch (IOException e) { } } return null; } public byte[] getFile2(String url){ SmbFileInputStream in = null; try { ByteArrayOutputStream out = new ByteArrayOutputStream(); SmbFile sf = new SmbFile(url); // 建立smb文件輸入流 in = new SmbFileInputStream(sf); byte[] b = new byte[4096]; int n; while(( n = in.read( b )) > 0 ) { out.write(b, 0, n); } return out.toByteArray(); } catch (Exception e) { e.printStackTrace(); } finally{ try { if (in != null) in.close(); } catch (IOException e) { } } return null; } public void print(String fileName, HttpServletResponse response, byte[] destFiles) throws Exception{ //檔案名稱 String encodeFileName = java.net.URLEncoder.encode(fileName, "UTF-8"); if(fileName.endsWith(".xls")) response.setContentType("application/vnd.ms-excel"); else response.setContentType("text/plain"); //加上下列兩行才可開啟檔案 //response.setHeader("Pragma", ""); //response.setHeader("Cache-Control", ""); //response.setHeader("Content-Disposition", "inline; filename=" + encodeFileName + ";"); //直接開啟檔案 response.setHeader("Content-Disposition","attachment; filename=" + encodeFileName + ";"); //另存新檔 InputStream is = null; javax.servlet.ServletOutputStream out = null; try { is = new ByteArrayInputStream(destFiles); out = response.getOutputStream(); byte buffer[] = new byte[4096]; response.flushBuffer(); for(int n = 0; -1 != (n = is.read(buffer));){ out.write(buffer, 0, n); } } finally { is.close(); } } %><% // --------不能有空行 String type = request.getParameter("type"); if ("1".equals(type)) { String url = URLDecoder.decode(request.getParameter("url"),"UTF-8"); if (url != null && !"".equals(url)) { String name = URLDecoder.decode(request.getParameter("name"),"UTF-8"); byte[] file = getFile2(url); if (file != null) { print(name, response, file); } } } else { java.util.List files = getFileList("smb://账号:密码@主机名或IP/Temp/"); if (files != null) { out.println("<table border='1'>"); Map data = null; for (int i = 0; i < files.size(); i++) { data = (Map) files.get(i); out.println("<tr><td><a target='dataframe' href='" + request.getContextPath() + "/smb.jsp?type=1&url=" + data.get("recordurlall") + "&name=" + data.get("name") + "'>" + URLDecoder.decode((String)data.get("name"),"UTF-8") + "</a><td></tr>"); } out.println("</table>"); out.println("<iframe name='dataframe' width='0' height='0'></iframe>"); } } %>3. 效果如下图： 注意： 为了保证下载文件不损坏，在JSP中的<%...%><%...%>之间不能有任何换行或空白，否则就会出现多出了些空行从而导致源文件损坏，当然如果用Servlet或 Struts等Java端实现就不会存在这样的问题……
相关资源：java 读取局域网机器上共享文件
