struts实现的文件上传下载功能

package com.hailong.util; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URLEncoder; import java.text.SimpleDateFormat; import java.util.Date; import java.util.List; import java.util.Random; import javax.servlet.http.HttpServletResponse; import org.apache.commons.configuration.Configuration; import org.apache.commons.configuration.ConfigurationException; import org.apache.commons.configuration.PropertiesConfiguration; import org.apache.commons.io.IOUtils; import org.apache.struts.upload.FormFile; import sun.net.TelnetInputStream; import sun.net.TelnetOutputStream; import sun.net.ftp.FtpClient; /** * FTP处理文件上传下载 * @author xzh * */ public class FtpFileManager { private FtpClient ftpClient; private static final String MAX_SIZE = "1M"; //上传文件重命名随机数 private static final int RANDOMINT = 999999; // 模块名 private String moduleName; /** * 构造方法 * * @param moduleName * 模块名 */ public FtpFileManager(String moduleName) { this.moduleName = moduleName; } /** * 链接FTP服务器 * @throws IOException IOException * @throws ThirdgsException ThirdgsException */ private void connectServer() throws IOException, ThirdgsException { Configuration config = this.getConfig(); if (config == null) { throw new ThirdgsException("未找到相关的配置!"); } //server：FTP服务器的IP地址 String server = config.getString("ftp.server"); int port = 21; try { //port:FTP端口 port = new Integer(config.getString("ftp.port")).intValue(); } catch (Exception e) { //若端口配置不合法,默认21 } //user:登录FTP服务器的用户名 String user = config.getString("ftp.user"); //password：登录FTP服务器的密码 String password = config.getString("ftp.password"); //path：FTP服务器上的路径(FTP服务下主目录的子目录) String path = config.getString("ftp.path"); ftpClient = new FtpClient(); try { ftpClient.openServer(server, port); ftpClient.login(user, password); } catch (Exception e) { throw new ThirdgsException("FTP登录失败,原因:" + e.getMessage()); } // path是FTP服务下主目录的子目录 if (path.length() != 0) { ftpClient.cd(path); } try { //在FTP上创建目录 : XMKD 命令 ftpClient.sendServer("XMKD " + moduleName + "\r\n"); } catch (Exception e) { //若存在则忽略 } //使用sendserver发送命令后，需要接收服务器的相应后才能继续下面的操作. ftpClient.readServerResponse(); ftpClient.cd(moduleName); // 用2进制上传 ftpClient.binary(); } /** * 退出FTP服务器 * @throws IOException IOException */ private void logout() throws IOException { if (null != ftpClient) { ftpClient.closeServer(); } } /** * * @param formFile 文件对象 * @return String * @throws IOException IOException * @throws ThirdgsException ThirdgsException */ public String uploadFile(FormFile formFile) throws IOException, ThirdgsException { try { this.validate(formFile); this.connectServer(); String filename = this.saveFileToServer(formFile); return filename; } finally { this.logout(); } } /** * 下载文件 * @param fileName 下载文件名 * @param response response * @throws Exception Exception */ public void downFile(String fileName, HttpServletResponse response) throws Exception { try { this.connectServer(); this.download(fileName, response); } finally { this.logout(); } } /** * 查看图片 * @param fileName 查看图片名 * @param response response * @throws Exception Exception */ public void showPic(String fileName, HttpServletResponse response) throws Exception { try { this.connectServer(); this.show(fileName, response); } finally { this.logout(); } } /** * 得到文件服务基地址 * @return String * @throws ConfigurationException ConfigurationException */ public String getBaseUrl() throws ConfigurationException { Configuration config = new PropertiesConfiguration("adc_web_config.properties"); String baseUrl = config.getString("file.root.url") + "/" + moduleName; return baseUrl; } /** * 上传文件;并返回上传文件的名称 * @param formFile formFile * @return String * @throws ThirdgsException ThirdgsException * @throws IOException IOException */ private String saveFileToServer(FormFile formFile) throws IOException, ThirdgsException { TelnetOutputStream os = null; InputStream is = null; String filename = "ftpup_" + getName() + "." + getExtName(formFile.getFileName()); try { os = ftpClient.put(filename); is = formFile.getInputStream(); IOUtils.copy(is, os); } catch (IOException e) { throw new ThirdgsException("上传文件失败,原因:" + e.getMessage()); } finally { if (is != null) { is.close(); } if (os != null) { os.close(); } } return filename; } /** * 下载文件 * * @param fileName * FormFile对象 * @param response * HTTP响应 * @throws Exception Exception */ private void download(String fileName, HttpServletResponse response) throws Exception { TelnetInputStream ftpIn = ftpClient.get(fileName); response.setHeader("Content-disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8")); OutputStream out = null; try { out = response.getOutputStream(); IOUtils.copy(ftpIn, out); } catch (Exception e) { throw new ThirdgsException("下载文件失败,原因:" + e.getMessage()); } finally { if (ftpIn != null) { ftpIn.close(); } } } /** * 显示图片 * * @param fileName * FormFile对象 * @param response * HTTP响应 * @throws IOException IOException */ private void show(String fileName, HttpServletResponse response) throws IOException { TelnetInputStream ftpIn = ftpClient.get(fileName); OutputStream out = null; try { out = response.getOutputStream(); IOUtils.copy(ftpIn, out); } finally { if (ftpIn != null) { ftpIn.close(); } } } /** * * @return Configuration */ private Configuration getConfig() { Configuration config; try { config = new PropertiesConfiguration("adc_web_config.properties"); } catch (ConfigurationException e) { return null; } return config; } /** * 验证上传文件的合法性(类型,大小等) * @param formFile formFile * @throws ThirdgsException ThirdgsException */ private voi