1、原理就不介绍了，大家直接看代码
2、/*** Description: 向FTP服务器上传文件* @Version1.0 Jul 2蚀卺垦肝7, 2008 桃轾庾殇4:31:09 PM by 崔红保（[email protected]）创建* @param url FTP服务器hostname* @param port FTP服务器端口* @param username FTP登录账号* @param password FTP登录密码* @param path FTP服务器保存目录* @param filename 上传到FTP服务器上的文件名* @param input 输入流* @return 成功返回true，否则返回false*/publicstaticboolean uploadFile(String url,int port,String username, String password, String path, String filename, InputStream input) {boolean success = false;FTPClient ftp = new FTPClient();try {int reply;ftp.connect(url, port);//连接FTP服务器//如果采用默认端口，可以使用ftp.connect(url)的方式直接连接FTP服务器ftp.login(username, password);//登录reply = ftp.getReplyCode();if (!FTPReply.isPositiveCompletion(reply)) {ftp.disconnect();return success;}ftp.changeWorkingDirectory(path);ftp.storeFile(filename, input);input.close();ftp.logout();success = true;} catch (IOException e) {e.printStackTrace();} finally {if (ftp.isConnected()) {try {ftp.disconnect();} catch (IOException ioe) {}}}return success;}<pre></pre>/*** Description: 向FTP服务器上传文件* @Version1.0 Jul 27, 2008 4:31:09 PM by 崔红保（[email protected]）创建* @param url FTP服务器hostname* @param port FTP服务器端口* @param username FTP登录账号* @param password FTP登录密码* @param path FTP服务器保存目录* @param filename 上传到FTP服务器上的文件名* @param input 输入流* @return 成功返回true，否则返回false*/public static boolean uploadFile(String url,int port,String username, String password, String path, String filename, InputStream input) {boolean success = false;FTPClient ftp = new FTPClient();try {int reply;ftp.connect(url, port);//连接FTP服务器//如果采用默认端口，可以使用ftp.connect(url)的方式直接连接FTP服务器ftp.login(username, password);//登录reply = ftp.getReplyCode();if (!FTPReply.isPositiveCompletion(reply)) {ftp.disconnect();return success;}ftp.changeWorkingDirectory(path);ftp.storeFile(filename, input);input.close();ftp.logout();success = true;} catch (IOException e) {e.printStackTrace();} finally {if (ftp.isConnected()) {try {ftp.disconnect();} catch (IOException ioe) {}}}return success;}
3、两个小例子：1.将本地文件上传到FTP服务器上，代码如下：
4、@Testpublicvoid testUpLoadFromDisk(){try {FileInputStream in=new FileInputStream(new File("D:/test.txt"));boolean flag = uploadFile("127.0.0.1", 21, "test", "test", "D:/ftp", "test.txt", in);System.out.println(flag);} catch (FileNotFoundException e) {e.printStackTrace();}}<pre></pre>@Testpublic void testUpLoadFromDisk(){try {FileInputStream in=new FileInputStream(new File("D:/test.txt"));boolean flag = uploadFile("127.0.0.1", 21, "test", "test", "D:/ftp", "test.txt", in);System.out.println(flag);} catch (FileNotFoundException e) {e.printStackTrace();}}
5、在FTP服务器上生成一个文件，并将一个字符串写入到该文件中
6、@Testpublicvoid testUpLoadFromString(){try {InputStrea罪焐芡拂m input = new ByteArrayInputStream("test ftp".getBytes("utf-8"));boolean flag = uploadFile("127.0.0.1", 21, "test", "test", "D:/ftp", "test.txt", input);System.out.println(flag);} catch (UnsupportedEncodingException e) {e.printStackTrace();}}<pre></pre>@Testpublic void testUpLoadFromString(){try {InputStream input = new ByteArrayInputStream("test ftp".getBytes("utf-8"));boolean flag = uploadFile("127.0.0.1", 21, "test", "test", "D:/ftp", "test.txt", input);System.out.println(flag);} catch (UnsupportedEncodingException e) {e.printStackTrace();}}