Java 实现ftp 文件上传、下载和删除

本文利用apache ftp工具实现文件的上传下载和删除。具体如下：

1、下载相应的jar包

commons-net-1.4.1.jar

2、实现代码如下：

public class FtpUtils {
        //ftp服务器地址
        public String hostname = "192.168.1.249";
        //ftp服务器端口号默认为21
        public Integer port = 21 ;
        //ftp登录账号
        public String username = "root";
        //ftp登录密码
        public String password = "123";

        public FTPClient ftpClient = null;

        /**
         * 初始化ftp服务器
         */
        public void initFtpClient() {
            ftpClient = new FTPClient();
            ftpClient.setControlEncoding("utf-8");
            try {
                System.out.println("connecting...ftp服务器:"+this.hostname+":"+this.port);
                ftpClient.connect(hostname, port); //连接ftp服务器
                ftpClient.login(username, password); //登录ftp服务器
                int replyCode = ftpClient.getReplyCode(); //是否成功登录服务器
                if(!FTPReply.isPositiveCompletion(replyCode)){
                    System.out.println("connect failed...ftp服务器:"+this.hostname+":"+this.port);
                }
                System.out.println("connect successfu...ftp服务器:"+this.hostname+":"+this.port);
            }catch (MalformedURLException e) {
               e.printStackTrace();
            }catch (IOException e) {
               e.printStackTrace();
            }
        }

        /**
        * 上传文件
        * @param pathname ftp服务保存地址
        * @param fileName 上传到ftp的文件名
        *  @param originfilename 待上传文件的名称（绝对地址） *
        * @return
        */
        public boolean uploadFile( String pathname, String fileName,String originfilename){
            boolean flag = false;
            InputStream inputStream = null;
            try{
                System.out.println("开始上传文件");
                inputStream = new FileInputStream(new File(originfilename));
                initFtpClient();
                ftpClient.setFileType(ftpClient.BINARY_FILE_TYPE);
                CreateDirecroty(pathname);
                ftpClient.makeDirectory(pathname);
                ftpClient.changeWorkingDirectory(pathname);
                ftpClient.storeFile(fileName, inputStream);
                inputStream.close();
                ftpClient.logout();
                flag = true;
                System.out.println("上传文件成功");
            }catch (Exception e) {
                System.out.println("上传文件失败");
                e.printStackTrace();
            }finally{
                if(ftpClient.isConnected()){
                    try{
                        ftpClient.disconnect();
                    }catch(IOException e){
                        e.printStackTrace();
                    }
                }
                if(null != inputStream){
                    try {
                        inputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            return true;
        }
        /**
         * 上传文件
         * @param pathname ftp服务保存地址
         * @param fileName 上传到ftp的文件名
         * @param inputStream 输入文件流
         * @return
         */
        public boolean uploadFile( String pathname, String fileName,InputStream inputStream){
            boolean flag = false;
            try{
                System.out.println("开始上传文件");
                initFtpClient();
                ftpClient.setFileType(ftpClient.BINARY_FILE_TYPE);
                CreateDirecroty(pathname);
                ftpClient.makeDirectory(pathname);
                ftpClient.changeWorkingDirectory(pathname);
                ftpClient.storeFile(fileName, inputStream);
                inputStream.close();
                ftpClient.logout();
                flag = true;
                System.out.println("上传文件成功");
            }catch (Exception e) {
                System.out.println("上传文件失败");
                e.printStackTrace();
            }finally{
                if(ftpClient.isConnected()){
                    try{
                        ftpClient.disconnect();
                    }catch(IOException e){
                        e.printStackTrace();
                    }
                }
                if(null != inputStream){
                    try {
                        inputStream.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            return true;
        }
        //改变目录路径
         public boolean changeWorkingDirectory(String directory) {
                boolean flag = true;
                try {
                    flag = ftpClient.changeWorkingDirectory(directory);
                    if (flag) {
                      System.out.println("进入文件夹" + directory + " 成功！");

                    } else {
                        System.out.println("进入文件夹" + directory + " 失败！开始创建文件夹");
                    }
                } catch (IOException ioe) {
                    ioe.printStackTrace();
                }
                return flag;
            }

        //创建多层目录文件，如果有ftp服务器已存在该文件，则不创建，如果无，则创建
        public boolean CreateDirecroty(String remote) throws IOException {
            boolean success = true;
            String directory = remote + "/";
            // 如果远程目录不存在，则递归创建远程服务器目录
            if (!directory.equalsIgnoreCase("/") && !changeWorkingDirectory(new String(directory))) {
                int start = 0;
                int end = 0;
                if (directory.startsWith("/")) {
                    start = 1;
                } else {
                    start = 0;
                }
                end = directory.indexOf("/", start);
                String path = "";
                String paths = "";
                while (true) {
                    String subDirectory = new String(remote.substring(start, end).getBytes("GBK"), "iso-8859-1");
                    path = path + "/" + subDirectory;
                    if (!existFile(path)) {
                        if (makeDirectory(subDirectory)) {
                            changeWorkingDirectory(subDirectory);
                        } else {
                            System.out.println("创建目录[" + subDirectory + "]失败");
                            changeWorkingDirectory(subDirectory);
                        }
                    } else {
                        changeWorkingDirectory(subDirectory);
                    }

                    paths = paths + "/" + subDirectory;
                    start = end + 1;
                    end = directory.indexOf("/", start);
                    // 检查所有目录是否创建完毕
                    if (end <= start) {
                        break;
                    }
                }
            }
            return success;
        }

      //判断ftp服务器文件是否存在
        public boolean existFile(String path) throws IOException {
                boolean flag = false;
                FTPFile[] ftpFileArr = ftpClient.listFiles(path);
                if (ftpFileArr.length > 0) {
                    flag = true;
                }
                return flag;
            }
        //创建目录
        public boolean makeDirectory(String dir) {
            boolean flag = true;
            try {
                flag = ftpClient.makeDirectory(dir);
                if (flag) {
                    System.out.println("创建文件夹" + dir + " 成功！");

                } else {
                    System.out.println("创建文件夹" + dir + " 失败！");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return flag;
        }

        /** * 下载文件 *
        * @param pathname FTP服务器文件目录 *
        * @param filename 文件名称 *
        * @param localpath 下载后的文件路径 *
        * @return */
        public  boolean downloadFile(String pathname, String filename, String localpath){
            boolean flag = false;
            OutputStream os=null;
            try {
                System.out.println("开始下载文件");
                initFtpClient();
                //切换FTP目录
                ftpClient.changeWorkingDirectory(pathname);
                FTPFile[] ftpFiles = ftpClient.listFiles();
                for(FTPFile file : ftpFiles){
                    if(filename.equalsIgnoreCase(file.getName())){
                        File localFile = new File(localpath + "/" + file.getName());
                        os = new FileOutputStream(localFile);
                        ftpClient.retrieveFile(file.getName(), os);
                        os.close();
                    }
                }
                ftpClient.logout();
                flag = true;
                System.out.println("下载文件成功");
            } catch (Exception e) {
                System.out.println("下载文件失败");
                e.printStackTrace();
            } finally{
                if(ftpClient.isConnected()){
                    try{
                        ftpClient.disconnect();
                    }catch(IOException e){
                        e.printStackTrace();
                    }
                }
                if(null != os){
                    try {
                        os.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
            return flag;
        }

        /** * 删除文件 *
        * @param pathname FTP服务器保存目录 *
        * @param filename 要删除的文件名称 *
        * @return */
        public boolean deleteFile(String pathname, String filename){
            boolean flag = false;
            try {
                System.out.println("开始删除文件");
                initFtpClient();
                //切换FTP目录
                ftpClient.changeWorkingDirectory(pathname);
                ftpClient.dele(filename);
                ftpClient.logout();
                flag = true;
                System.out.println("删除文件成功");
            } catch (Exception e) {
                System.out.println("删除文件失败");
                e.printStackTrace();
            } finally {
                if(ftpClient.isConnected()){
                    try{
                        ftpClient.disconnect();
                    }catch(IOException e){
                        e.printStackTrace();
                    }
                }
            }
            return flag;
        }

        public static void main(String[] args) {
            FtpUtils ftp =new FtpUtils();
            //ftp.uploadFile("ftpFile/data", "123.docx", "E://123.docx");
            //ftp.downloadFile("ftpFile/data", "123.docx", "F://");
            ftp.deleteFile("ftpFile/data", "123.docx");
            System.out.println("ok");
        }
}