Java 如何将文件上传到 FTP 服务器？

How do you upload a file to an FTP server?

提问by Mike

I created a function to download files from an FTP server that I have access to. How would I upload files back to the FTP server?

我创建了一个函数来从我有权访问的 FTP 服务器下载文件。如何将文件上传回 FTP 服务器？

Below is the download_files method i used:

下面是我使用的 download_files 方法：

public static void download_files(String un, String pw, String ip, String dir, String fn, String fp){

    URLConnection con;
    BufferedInputStream in = null;
    FileOutputStream out = null;

    try{
        URL url = new URL("ftp://"+un+":"+pw+"@"+ip+"/"+dir+"/"+fn+";type=i");
        con = url.openConnection();
        in = new BufferedInputStream(con.getInputStream());
        out = new FileOutputStream(fp+fn);

        int i = 0;
        byte[] bytesIn = new byte[1024];

        while ((i = in.read(bytesIn)) >= 0) {
            out.write(bytesIn, 0, i);
        }

    }catch(Exception e){
        System.out.print(e);
        e.printStackTrace();
        System.out.println("Error while FTP'ing "+fn);
    }finally{
        try{
            out.close();
            in.close();
        }catch(IOException e){
            e.printStackTrace();
            System.out.println("Error while closing FTP connection");
        }
    }
}

采纳答案by Marcelo

Use the FTPClientClass from the Apache Commons Netlibrary.

使用Apache Commons Net库中的FTPClient类。

This is a snippet with an example:

这是一个带有示例的片段：

FTPClient client = new FTPClient();
FileInputStream fis = null;

try {
    client.connect("ftp.domain.com");
    client.login("admin", "secret");

    //
    // Create an InputStream of the file to be uploaded
    //
    String filename = "Touch.dat";
    fis = new FileInputStream(filename);

    //
    // Store file to server
    //
    client.storeFile(filename, fis);
    client.logout();
} catch (IOException e) {
    e.printStackTrace();
} finally {
    try {
        if (fis != null) {
            fis.close();
        }
        client.disconnect();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

Snippet taken from http://www.kodejava.org/examples/356.html

摘自http://www.kodejava.org/examples/356.html 的片段

回答by Michael J. Lee

Take a look at apache-commons-netthey have a some FTP tools which may help you out!

看看apache-commons-net他们有一些 FTP 工具可以帮助你！

回答by Steven

I have used the EDT FTP package, a free GPL library for FTP in Java: http://www.enterprisedt.com/products/edtftpj/overview.html

我使用了 EDT FTP 包，这是一个用于 Java FTP 的免费 G​​PL 库：http: //www.enterprisedt.com/products/edtftpj/overview.html

Here is a code sample, from the Demo.java class they provide:

这是一个代码示例，来自他们提供的 Demo.java 类：

ftp = new FTPClient();
ftp.setRemoteHost("hostname");

// connect
ftp.connect();

// login
ftp.login("user", "password");

// set up passive ASCII transfers
ftp.setConnectMode(FTPConnectMode.PASV);
ftp.setType(FTPTransferType.ASCII);

// get directory and print it to console            
String[] files = ftp.dir(".", true);
for (int i = 0; i < files.length; i++)
    log.debug(files[i]);

// copy file to server 
ftp.put("test.txt", "test.txt");

// copy file from server
ftp.get("test.txt" + ".copy", "test.txt");

// delete file from server
ftp.delete("test.txt");

// Shut down client                
ftp.quit();

回答by helios

Check out FTP4Jas well...

检查FTP4J以及...