知识点：

springBoot后端项目，接收前端框架传到的图片，把图片上传到ftp图片服务器上

注意：在上传的过程中可能回出现，可以创建文件夹，但是图片上传不了的问题；

尝试了网上的很多方法，最后将filename改为全路径上传成功

1. pom.xml中引入依赖的包

<!-- 加入上传文件组件 -->
<!-- https://mvnrepository.com/artifact/commons-net/commons-net -->
<dependency>
   <groupId>commons-net</groupId>
   <artifactId>commons-net</artifactId>
   <version>3.3</version>
</dependency>

2.ftp上传工具类FtpFileUtil.java

package com.hand.hand.util;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;

import java.io.IOException;
import java.io.InputStream;

/**
 * Created by nishuai on 2018/1/12.
 */
public class FtpFileUtil {

    //ftp服务器ip地址
    private static final String FTP_ADDRESS = "101.132.1.113";
    //端口号
    private static final int FTP_PORT = 21;
    //用户名
    private static final String FTP_USERNAME = "ftp";
    //密码
    private static final String FTP_PASSWORD = "123456";
    //图片路径
    private static final String FTP_BASEPATH = "/home/ftpadmin/health/images";

    public  static boolean uploadFile(String originFileName,InputStream input){
        boolean success = false;
        FTPClient ftp = new FTPClient();
        ftp.setControlEncoding("GBK");
        try {
            int reply;
            ftp.connect(FTP_ADDRESS, FTP_PORT);// 连接FTP服务器
            ftp.login(FTP_USERNAME, FTP_PASSWORD);// 登录
            reply = ftp.getReplyCode();
            if (!FTPReply.isPositiveCompletion(reply)) {
                ftp.disconnect();
                return success;
            }
            ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
            ftp.makeDirectory(FTP_BASEPATH );
            ftp.changeWorkingDirectory(FTP_BASEPATH );
            ftp.storeFile(originFileName,input);
            input.close();
            ftp.logout();
            success = true;
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (ftp.isConnected()) {
                try {
                    ftp.disconnect();
                } catch (IOException ioe) {
                }
            }
        }
        return success;
    }

}

3.controller层接口 FtpFileUploadController.java

package com.hand.hand.controller;
import com.hand.hand.util.FtpFileUtil;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
import java.io.InputStream;

/**
 * Created by nishuai on 2017/12/26.
 */
@CrossOrigin
@Controller
public class FtpFileUploadController {

    //ftp处理文件上传
    @RequestMapping(value="/ftpuploadimg", method = RequestMethod.POST)
    public @ResponseBody String uploadImg(@RequestParam("file") MultipartFile file,
                                          HttpServletRequest request) throws IOException {

        String fileName = file.getOriginalFilename();
        InputStream inputStream=file.getInputStream();
        String filePath=null;

        Boolean flag=FtpFileUtil.uploadFile(fileName,inputStream);
        if(flag==true){
            System.out.println("ftp上传成功！");
            filePath=fileName;
        }

        return  filePath;  //该路径图片名称，前端框架可用ngnix指定的路径+filePath,即可访问到ngnix图片服务器中的图片
    }

}