Spring SpringMVC使用MultipartFile实现文件的上传

    如果需要实现跨服务器上传文件，就是将我们本地的文件上传到资源服务器上，比较好的办法就是通过ftp上传。这里是结合SpringMVC+ftp的形式上传的。我们需要先懂得如何配置springMVC，然后在配置ftp，最后再结合MultipartFile上传文件。

springMVC上传需要几个关键jar包，spring以及关联包可以自己配置，这里主要说明关键的jar包

1：spring-web-3.2.9.RELEASE.jar (spring的关键jar包，版本可以自己选择)

2：commons-io-2.2.jar (项目中用来处理IO的一些工具类包)

配置文件

SpringMVC是用MultipartFile来进行文件上传的，因此我们先要配置MultipartResolver，用于处理表单中的file

<!-- 上传文件解释器 --><bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"><property name="defaultEncoding" value="utf-8" /><property name="maxUploadSize" value="10485760" /><property name="maxInMemorySize" value="4096" /><property name="resolveLazily" value="true" /></bean>

其中属性详解：

defaultEncoding配置请求的编码格式，默认为iso-8859-1

maxUploadSize配置文件的最大单位，单位为字节

maxInMemorySize配置上传文件的缓存 ，单位为字节

resolveLazily属性启用是为了推迟文件解析，以便在UploadAction 中捕获文件大小异常

页面配置

在页面的form中加上enctype="multipart/form-data"

<form id="" name="" method="post" action="" enctype="multipart/form-data"> 

表单标签中设置enctype="multipart/form-data"来确保匿名上载文件的正确编码。 

是设置表单的MIME编码。默认情况，这个编码格式是application/x-www-form-urlencoded，不能用于文件上传；只有使用了multipart/form-data，才能完整的传递文件数据，进行下面的操作。enctype="multipart/form-data"是上传二进制数据。form里面的input的值以2进制的方式传过去，所以request就得不到值了。

编写上传控制类

编写一个上传方法，这里没有返回结果，需要跳转页面或者返回其他值可以将void改为String、Map<String,Object>等值，再return返回结果。

        /** * 上传 * @param request * @return */@ResponseBody@RequestMapping(value = "/upload", method = {RequestMethod.GET, RequestMethod.POST})public void upload(HttpServletRequest request) {MultipartHttpServletRequest multipartRequest=(MultipartHttpServletRequest)request;MultipartFile file = multipartRequest.getFile("file");//file是页面input的name名String basePath = "文件路径"try {MultipartResolver resolver = new CommonsMultipartResolver(request.getSession().getServletContext());  if (resolver.isMultipart(request)) {String fileStoredPath =  "文件夹路径";//随机生成文件名String randomName = StringUtil.getRandomFileName();String uploadFileName = file.getOriginalFilename();if (StringUtils.isNotBlank(uploadFileName)) {//截取文件格式名String suffix = uploadFileName.substring(uploadFileName.indexOf("."));//重新拼装文件名String newFileName = randomName + suffix;String savePath = basePath + "/" + newFileName;File saveFile = new File(savePath);File parentFile = saveFile.getParentFile();if (saveFile.exists()) {saveFile.delete();} else {if (!parentFile.exists()) {parentFile.mkdirs();}}//复制文件到指定路径FileUtils.copyInputStreamToFile(file.getInputStream(), saveFile);//上传文件到服务器FTPClientUtil.upload(saveFile, fileStoredPath);}}} catch (Exception e) {e.printStackTrace();}}

FTP客户端上传工具

package com.yuanding.common.util;import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.SocketException;import java.util.HashMap;import java.util.Map;import java.util.Properties;import org.apache.commons.lang.StringUtils;import org.apache.commons.net.ftp.FTP;import org.apache.commons.net.ftp.FTPClient;import org.apache.commons.net.ftp.FTPReply;import org.slf4j.Logger;import org.slf4j.LoggerFactory;/** * FTP客户端工具 */public class FTPClientUtil {/** * 日志 */private static final Logger LOGGER = LoggerFactory.getLogger(FTPClientUtil.class);/** * FTP server configuration--IP key,value is type of String */public static final String SERVER_IP = "SERVER_IP";/** * FTP server configuration--Port key,value is type of Integer */public static final String SERVER_PORT = "SERVER_PORT";/** * FTP server configuration--ANONYMOUS Log in key, value is type of Boolean */public static final String IS_ANONYMOUS = "IS_ANONYMOUS";/** * user name of anonymous log in */public static final String ANONYMOUS_USER_NAME = "anonymous";/** * password of anonymous log in */public static final String ANONYMOUS_PASSWORD = "";/** * FTP server configuration--log in user name, value is type of String */public static final String USER_NAME = "USER_NAME";/** * FTP server configuration--log in password, value is type of String */public static final String PASSWORD = "PASSWORD";/** * FTP server configuration--PASV key, value is type of Boolean */public static final String IS_PASV = "IS_PASV";/** * FTP server configuration--working directory key, value is type of String While logging in, the current directory * is the user's home directory, the workingDirectory must be set based on it. Besides, the workingDirectory must * exist, it can not be created automatically. If not exist, file will be uploaded in the user's home directory. If * not assigned, "/" is used. */public static final String WORKING_DIRECTORY = "WORKING_DIRECTORY";public static Map<String, Object> serverCfg = new HashMap<String, Object>();static Properties prop;static{LOGGER.info("开始加载ftp.properties文件!");prop = new Properties();try {InputStream fps = FTPClientUtil.class.getResourceAsStream("/ftp.properties");prop.load(fps);fps.close();} catch (Exception e) {LOGGER.error("读取ftp.properties文件异常!",e);}serverCfg.put(FTPClientUtil.SERVER_IP, values("SERVER_IP"));serverCfg.put(FTPClientUtil.SERVER_PORT, Integer.parseInt(values("SERVER_PORT")));serverCfg.put(FTPClientUtil.USER_NAME, values("USER_NAME"));serverCfg.put(FTPClientUtil.PASSWORD, values("PASSWORD"));LOGGER.info(String.valueOf(serverCfg));}/** * Upload a file to FTP server. *  * @param serverCfg : FTP server configuration * @param filePathToUpload : path of the file to upload * @param fileStoredName : the name to give the remote stored file, null, "" and other blank word will be replaced *            by the file name to upload * @throws IOException * @throws SocketException */public static final void upload(Map<String, Object> serverCfg, String filePathToUpload, String fileStoredName)throws SocketException, IOException {upload(serverCfg, new File(filePathToUpload), fileStoredName);}/** * Upload a file to FTP server. *  * @param serverCfg : FTP server configuration * @param fileToUpload : file to upload * @param fileStoredName : the name to give the remote stored file, null, "" and other blank word will be replaced *            by the file name to upload * @throws IOException * @throws SocketException */public static final void upload(Map<String, Object> serverCfg, File fileToUpload, String fileStoredName)throws SocketException, IOException {if (!fileToUpload.exists()) {throw new IllegalArgumentException("File to upload does not exists：" + fileToUpload.getAbsolutePath());}if (!fileToUpload.isFile()) {throw new IllegalArgumentException("File to upload is not a file:" + fileToUpload.getAbsolutePath());}if (StringUtils.isBlank((String) serverCfg.get(SERVER_IP))) {throw new IllegalArgumentException("SERVER_IP must be contained in the FTP server configuration.");}transferFile(true, serverCfg, fileToUpload, fileStoredName, null, null);}/** * Download a file from FTP server *  * @param serverCfg : FTP server configuration * @param fileNameToDownload : file name to be downloaded * @param fileStoredPath : stored path of the downloaded file in local * @throws SocketException * @throws IOException */public static final void download(Map<String, Object> serverCfg, String fileNameToDownload, String fileStoredPath)throws SocketException, IOException {if (StringUtils.isBlank(fileNameToDownload)) {throw new IllegalArgumentException("File name to be downloaded can not be blank.");}if (StringUtils.isBlank(fileStoredPath)) {throw new IllegalArgumentException("Stored path of the downloaded file in local can not be blank.");}if (StringUtils.isBlank((String) serverCfg.get(SERVER_IP))) {throw new IllegalArgumentException("SERVER_IP must be contained in the FTP server configuration.");}transferFile(false, serverCfg, null, null, fileNameToDownload, fileStoredPath);}private static final void transferFile(boolean isUpload, Map<String, Object> serverCfg, File fileToUpload,String serverFileStoredName, String fileNameToDownload, String localFileStoredPath) throws SocketException,IOException {String host = (String) serverCfg.get(SERVER_IP);Integer port = (Integer) serverCfg.get(SERVER_PORT);Boolean isAnonymous = (Boolean) serverCfg.get(IS_ANONYMOUS);String username = (String) serverCfg.get(USER_NAME);String password = (String) serverCfg.get(PASSWORD);Boolean isPASV = (Boolean) serverCfg.get(IS_PASV);String workingDirectory = (String) serverCfg.get(WORKING_DIRECTORY);FTPClient ftpClient = new FTPClient();InputStream fileIn = null;OutputStream fileOut = null;try {if (port == null) {LOGGER.debug("Connect to FTP server on " + host + ":" + FTP.DEFAULT_PORT);ftpClient.connect(host);} else {LOGGER.debug("Connect to FTP server on " + host + ":" + port);ftpClient.connect(host, port);}int reply = ftpClient.getReplyCode();if (!FTPReply.isPositiveCompletion(reply)) {LOGGER.error("FTP server refuses connection");return;}if (isAnonymous != null && isAnonymous) {username = ANONYMOUS_USER_NAME;password = ANONYMOUS_PASSWORD;}LOGGER.debug("Log in FTP server with username = " + username + ", password = " + password);if (!ftpClient.login(username, password)) {LOGGER.error("Fail to log in FTP server with username = " + username + ", password = " + password);ftpClient.logout();return;}// Here we will use the BINARY mode as the transfer file type,// ASCII mode is not supportted.LOGGER.debug("Set type of the file, which is to upload, to BINARY.");ftpClient.setFileType(FTP.BINARY_FILE_TYPE);if (isPASV != null && isPASV) {LOGGER.debug("Use the PASV mode to transfer file.");ftpClient.enterLocalPassiveMode();} else {LOGGER.debug("Use the ACTIVE mode to transfer file.");ftpClient.enterLocalActiveMode();}if (StringUtils.isBlank(workingDirectory)) {workingDirectory = "/";}LOGGER.debug("Change current working directory to " + workingDirectory);changeWorkingDirectory(ftpClient,workingDirectory);if (isUpload) { // uploadif (StringUtils.isBlank(serverFileStoredName)) {serverFileStoredName = fileToUpload.getName();}fileIn = new FileInputStream(fileToUpload);LOGGER.debug("Upload file : " + fileToUpload.getAbsolutePath() + " to FTP server with name : "+ serverFileStoredName);if (!ftpClient.storeFile(serverFileStoredName, fileIn)) {LOGGER.error("Fail to upload file, " + ftpClient.getReplyString());} else {LOGGER.debug("Success to upload file.");}} else { // download// make sure the file directory existsFile fileStored = new File(localFileStoredPath);if (!fileStored.getParentFile().exists()) {fileStored.getParentFile().mkdirs();}fileOut = new FileOutputStream(fileStored);LOGGER.debug("Download file : " + fileNameToDownload + " from FTP server to local : "+ localFileStoredPath);if (!ftpClient.retrieveFile(fileNameToDownload, fileOut)) {LOGGER.error("Fail to download file, " + ftpClient.getReplyString());} else {LOGGER.debug("Success to download file.");}}ftpClient.noop();ftpClient.logout();} finally {if (ftpClient.isConnected()) {try {ftpClient.disconnect();} catch (IOException f) {}}if (fileIn != null) {try {fileIn.close();} catch (IOException e) {}}if (fileOut != null) {try {fileOut.close();} catch (IOException e) {}}}}private static final boolean changeWorkingDirectory(FTPClient ftpClient, String workingDirectory) throws IOException{if(!ftpClient.changeWorkingDirectory(workingDirectory)){String [] paths = workingDirectory.split("/");for(int i=0 ;i<paths.length ;i++){if(!"".equals(paths[i])){if(!ftpClient.changeWorkingDirectory(paths[i])){ftpClient.makeDirectory(paths[i]);ftpClient.changeWorkingDirectory(paths[i]);}}}}return true;}public static final void upload(Map<String, Object> serverCfg, String filePathToUpload, String fileStoredPath, String fileStoredName)throws SocketException, IOException {upload(serverCfg, new File(filePathToUpload), fileStoredPath, fileStoredName);}public static final void upload(Map<String, Object> serverCfg, File fileToUpload, String fileStoredPath, String fileStoredName)throws SocketException, IOException {if(fileStoredPath!=null && !"".equals(fileStoredPath)){serverCfg.put(WORKING_DIRECTORY, fileStoredPath);}upload(serverCfg, fileToUpload, fileStoredName);}public static final void upload(String filePathToUpload, String fileStoredPath)throws SocketException, IOException {upload(serverCfg, filePathToUpload, fileStoredPath, "");}public static final void upload(File fileToUpload, String fileStoredPath)throws SocketException, IOException {upload(serverCfg, fileToUpload, fileStoredPath, "");}public static String values(String key) {String value = prop.getProperty(key);if (value != null) {return value;} else {return null;}}}

ftp.properties

#服务器地址SERVER_IP=192.168.1.1#服务器端口SERVER_PORT=21#帐号名USER_NAME=userftp#密码#PASSWORD=passwordftp

MultipartFileAPI

MultipartFilehttp://www.apihome.cn/api/spring/MultipartFile.html

参考文献：

http://blog.csdn.net/xiaojianpitt/article/details/6856536