Question

我想使用Java运行时类从sftp服务器下载文件。我不能使用像Jsch或SSHJ这样的库，因为我需要使用-B选项来增加缓冲区大小。到目前为止，我已尝试使用此代码：

public void download(String source, String destination,String port, String user, String host ){
    Runtime runtime = Runtime.getRuntime();
    String cmd = "sftp -oPort=" + port + " -B 150000 "+ user + "@" + host + ":" + source + " " + destination;

    String[] args = { "/bin/sh", "-c", cmd };
    try {
        long startTime = System.currentTimeMillis();
        log.info("cmd: "+ cmd);
        final Process process = runtime.exec(args);
        process.waitFor();
        long stopTime = System.currentTimeMillis();
        long elapsedTime = stopTime - startTime;
        System.out.println("Time: "+elapsedTime);

        BufferedReader bre = new BufferedReader(new InputStreamReader(process.getErrorStream()));
        StringBuffer sbe = new StringBuffer();
        String lineError;
        while ((lineError = bre.readLine()) != null) {   
          sbe.append(lineError).append("\n");
        }   
        String answerError = sbe.toString();
        if(answerError.length()>0)log.error("Error:"+answerError);
    } catch (IOException e) {
        e.printStackTrace();
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

我收到错误消息：正在连接xxxxxxx ... 使用主机的名称而不是＆＃34; xxxxxx＆＃34;

我已经在putty中直接尝试了这个命令并且效果很好但是当我在java中使用它时它根本不起作用。我还尝试使用runtime.exec（）的scp命令进行下载，而不是使用sftp进行下载。

有人知道为什么它不起作用？我找不到这种方法的例子。或者有人知道用于sftp传输的库，允许设置-B选项吗？我可能错过了Jsch和Sshj的方法。

提前致谢

Answer 1

我在Windows上使用psftp执行此操作。我希望你在* nix上使用sftp的结果应该是一样的。

 static java.io.File downloadFileViaSftp(String file) {
    String string = null;

    try {
        String c = "psftp -l user -P 22 -v -pw password hostname";
        Process p = Runtime.getRuntime().exec(c);

        OutputStream out = p.getOutputStream();

        Writer out2 = new BufferedWriter(new OutputStreamWriter(out));

        out2.write("get " + file + "\n");
        out2.flush();
        out2.write("close\n");
        out2.flush();
        out2.write("quit\n");
        out2.flush();
        out2.close();

        InputStream in = p.getInputStream();
        InputStream err = p.getErrorStream();

        BufferedReader bufferedreader1 = new BufferedReader(new InputStreamReader(in), 999999);
        BufferedReader bufferedreader2 = new BufferedReader(new InputStreamReader(err), 999999);

        while ((string = bufferedreader2.readLine()) != null) {
            System.out.println("2=" + string);
            System.out.flush();
        }
        bufferedreader2.close();

        while ((string = bufferedreader1.readLine()) != null) {
            System.out.println("1=" + string);
            System.out.flush();
        }
        bufferedreader1.close();

        int x = p.waitFor();
        p.destroy();

    } catch (Exception e) {
        e.printStackTrace();
        return null;
    }

    return new java.io.File(file);

}

使用runtime.exec发送SFTP命令

1 个答案: