java操作ftp下载文件示例

    /**
     *
     * java操作 ftp 下载
     * 文件下载。
     *
     */
    private void ftpdownload()
    {
        ftpclient ftpclient = null;
        inputstream input = null;
        boolean loginflag = false;
        list<string> list = new arraylist<string>();
        try
        {
            int defaultport = commonsmessage.ftp_default_port; // 21
            int timeout = m400constant.num_sixty_thousand * m400constant.num_two; // 120000
            ftpclient = new ftpclient();

            ftpclient.setdefaultport(defaultport);
            ftpclient.setconnecttimeout(timeout);
//            ftpclient.setsotimeout(timeout);
            ftpclient.setdefaulttimeout(timeout);
            ftpclient.setdatatimeout(timeout);
            ftpclient.setcontrolencoding("utf-8");
            ftpclientconfig conf = new ftpclientconfig(ftpclientconfig.syst_unix);
            conf.setserverlanguagecode("en");
            conf.setdefaultdateformatstr("mmm dd hh:mm");
            ftpclient.configure(conf);

            ftpclient.connect(systemconfig.getkey("scpftpip"));
            loginflag = ftpclient.login(systemconfig.getkey("scpftpusername").trim(),
                    systemconfig.getkey("scpftppassword").trim());
            string ftpdir = systemconfig.getkey("ftphangupdir").trim();
            if (!loginflag)
            {
                debugger.debug("login scp ftp is :" + loginflag);
            }
            // string ftpdir = systemconfig.getkey("ftphangupdir").trim();

            if (ftpclient.changeworkingdirectory(ftpdir))
            {
               

                ftpfile file[] = ftpclient.listfiles(ftpdir);

                if (file != null && file.length > 0)
                {
                    debugger.debug("hungup file size is:  " + file.length);
                    for (int i = 0; i < file.length; i++)
                    {
                        string filename = file[i].getname();
                        ftpclient.setbuffersize(commonsmessage.one_k_buffer_size);

                        // 设置文件类型（二进制）
                        ftpclient.setfiletype(ftp.binary_file_type);

                        input = ftpclient.retrievefilestream(filename);
                        processinput(ftpclient, input, list, filename);

                        // if (downflag) {
                        // ftpclient.deletefile(filename);
                        // }
                    }
                }
                else
                {
                    try
                    {
                        thread.sleep(m400constant.num_five_thousand);
                    }
                    catch (interruptedexception e)
                    {
                        /*
                         * if (debugger.isdebugenable()) {
                         * debugger.debug("failed to queryscptoquery", e); }
                         */
                        error("failed to queryscptoquery", e);
                    }
                }

            }
            else
            {
                debugger.debug("scp dir is error ");
            }

        }
        catch (exception e)
        {
            /*
             * debugger.debug("dowonload file is faild  ", e);
             */
            error("dowonload file is faild  ", e);
        }
        finally
        {
            close(input, "close inputstream  is faild  ");
            if (ftpclient != null)
            {
                try
                {
                    deletefile(ftpclient, list);
                    boolean logoutflag = false;
                    try
                    {
                        logoutflag = ftpclient.logout();
                        // debugger.debug("logout : " + logoutflag);
                    }
                    catch (exception e)
                    {
                        /*
                         * debugger.debug("logout : " + logoutflag);
                         */
                        error("logout : " + logoutflag, e);
                    }
                    ftpclient = null;
                }
                catch (exception e)
                {
                    /*
                     * if (debugger.isdebugenable()) {
                     * debugger.error("failed to ftpdownload", e); }
                     */
                    error("failed to ftpdownload", e);
                }
                // try {
                // ftpclient.disconnect();
                // } catch (ioexception e) {
                // if (debugger.isdebugenable()) {
                // debugger.debug("failed to ftpdownload", e);
                // }
                // }
            }
        }
    }

    /**
     * 处理ftp对应文件输入流。
     *
     * @param ftpclient
     *            ftp客户端对象
     * @param input
     *            ftp文件输入流
     * @param list
     *            处理完毕的文件列表，用于执行文件删除使用
     * @param filename
     *            当前处理的文件名称
     */
    private void processinput(ftpclient ftpclient, inputstream input, list<string> list, string filename)
    {
        if (input == null)
        {
            return;
        }
        // boolean downflag = callingservice(input);
        callingservice(input);
        try
        {
            input.close();
            ftpclient.completependingcommand();
            list.add(filename);
        }
        catch (exception e)
        {
            /*
             * debugger.debug("failed to ftpdownload", e);
             */
            error("failed to ftpdownload", e);
        }
    }
}