1、问题
在项目开发过程中，遇到需要将页面上选择的文件上传至FTP服务器，遇到一些坑，比如上传文件中文名乱码，上传时指定上传目录不能自动创建等问题。

2、FTP上传文件工具类

 public class FtpUtil {
    private String hostname = "xxx";
    private Integer port = 21 ;
    private String username = "xxx";
    private String password = "xxx";
    private FTPClient client = null;

    public String initialize() throws Exception{
        client = new FTPClient();
        client.setControlEncoding("utf-8");
        client.connect(hostname, port);
        client.login(username, password);
        int replyCode = client.getReplyCode();
        if(!FTPReply.isPositiveCompletion(replyCode))
            return "Connect ftp failed";

        return "success";
    }

    public String uploadFile(String storePath, String fileName, String uploadFile) throws Exception {
        InputStream stream = new FileInputStream(new File(uploadFile));
        client.setFileType(client.BINARY_FILE_TYPE);
        this.prepareStorePath(client, storePath);
        client.sendCommand("OPTS UTF8", "ON");
        client.storeFile(fileName, stream);
        if (client.storeFile(fileName, stream))
            return "Upload file success";

        return "Upload file failed";
    }

    private void prepareStorePath(FTPClient client, String storePath) throws Exception{
        String[] split = storePath.split("\\\\");

        for (String str : split) {
            if (StringUtils.isBlank(str))
                continue;

            if (!client.changeWorkingDirectory(str)) {
                client.makeDirectory(str);
                client.changeWorkingDirectory(str);
            }
        }
    }
}  

3、Application.java测试上传

 public class Application {
    public static void main(String[] args) throws Exception {
        FtpUtil ftp = new FtpUtil();
        ftp.initialize();
        ftp.uploadFile("uploads", "W3School离线手册2017.chm", "F:\\ToolFile\\W3School离线手册2017.chm");
    }
}  

4、文件名中文乱码解决办法

 client.sendCommand("OPTS UTF8", "ON");  

5、指定文件存储目录不能创建解决办法

 private void prepareStorePath(FTPClient client, String storePath) throws Exception{
    String[] split = storePath.split("\\\\");

    for (String str : split) {
        if (StringUtils.isBlank(str))
            continue;

        if (!client.changeWorkingDirectory(str)) {
            client.makeDirectory(str);
            client.changeWorkingDirectory(str);
        }
    }
}  

如果您有什么好的想法与方法，欢迎评论区留言，我们一起讨论~