图片上传到ftp服务器，用户图片的获取

<div class="am-u-md-4">
                    <img class="am-img-circle am-img-thumbnail" th:src="${userInformation.imgId}"/>
                </div>
                <div class="am-u-md-8">
                    <div class="layui-upload">
                        <button type="button" class="layui-btn" id="test2">更改头像</button>
                        <blockquote class="layui-elem-quote layui-quote-nm" style="margin-top: 10px;">
                            预览图：
                            <div class="layui-upload-list" id="demo2"></div>
                        </blockquote>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>

<script src="/js/layui.all.js" charset="utf-8"></script>
<script>
    layui.use('upload', function() {
        var $ = layui.jquery
            , upload = layui.upload;

        var id=0;
        //多图片上传
        var uploadInst = upload.render({

            elem: '#test2'
            ,url: '/addpic'
            ,multiple: true
            ,before: function(obj){
                //
                //预读本地文件示例，不支持ie8
                obj.preview(function(index, file, result){
                    id++;
                    $('#demo2').append('<img id="img'+id+'" src="'+ result +'" alt="'+ file.name +'" class="layui-upload-img">')

                });
            }
            , done: function (res) {
                alert("上传成功!"+id);
                $('#demo2').append('<button id="but'+id+'" onclick="delete1(\''+res.path+'\','+id+')\">删除</button>')
            }
        });
    });





</script>
<script>
    function delete1(path,id) {

        $.ajax({
            /*url:'/deleteoneimg',*/
            type:'GET',
            data:{
                path:path
            },
            success:function () {

                $("#img"+id).remove();
                $("#but"+id).remove();
            }
        });
    }
</script>

package com.dream.dreamsdtr.utils;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;

import java.io.*;
import java.net.MalformedURLException;

public class FTPUtils {
    //ftp服务器地址
    public String hostname = "10.2.3.132";
    //ftp服务器端口号默认为21
    public Integer port = 21;
    //ftp登录账号
    public String username = "ftpuser";
    //ftp登录密码
    public String password = "123456";

    public FTPClient ftpClient = null;

    public void initFtpClient() {
        ftpClient = new FTPClient();
        ftpClient.setControlEncoding("utf-8");
        try {
            System.out.println("connecting...ftp服务器:" + this.hostname + ":" + this.port);
            ftpClient.connect(hostname, port); //连接ftp服务器
            ftpClient.login(username, password); //登录ftp服务器
            int replyCode = ftpClient.getReplyCode(); //是否成功登录服务器
            if (!FTPReply.isPositiveCompletion(replyCode)) {
                System.out.println("connect failed...ftp服务器:" + this.hostname + ":" + this.port);
            }
            System.out.println("connect successfu...ftp服务器:" + this.hostname + ":" + this.port);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 上传文件
     *
     * @param pathname       ftp服务保存地址
     * @param fileName       上传到ftp的文件名
     * @return
     */
    public boolean uploadFile(String pathname, String fileName,FileInputStream inputStream) {
        boolean flag = false;

        try {
            System.out.println("开始上传文件");
            initFtpClient();
            ftpClient.setFileType(ftpClient.BINARY_FILE_TYPE);
            CreateDirecroty(pathname);
            ftpClient.makeDirectory(pathname);
            ftpClient.changeWorkingDirectory(pathname);
            ftpClient.storeFile(fileName, inputStream);
            inputStream.close();
            ftpClient.logout();
            flag = true;
            System.out.println("上传文件成功");
        } catch (Exception e) {
            System.out.println("上传文件失败");
            e.printStackTrace();
        } finally {
            if (ftpClient.isConnected()) {
                try {
                    ftpClient.disconnect();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != inputStream) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return true;
    }

    /**
     * 上传文件
     *
     * @param pathname    ftp服务保存地址
     * @param fileName    上传到ftp的文件名
     * @param inputStream 输入文件流
     * @return
     */
    public boolean uploadFile(String pathname, String fileName, InputStream inputStream) {
        boolean flag = false;
        try {
            System.out.println("开始上传文件");
            initFtpClient();
            ftpClient.setFileType(ftpClient.BINARY_FILE_TYPE);
            CreateDirecroty(pathname);
            ftpClient.makeDirectory(pathname);
            ftpClient.changeWorkingDirectory(pathname);
            ftpClient.storeFile(fileName, inputStream);
            inputStream.close();
            ftpClient.logout();
            flag = true;
            System.out.println("上传文件成功");
        } catch (Exception e) {
            System.out.println("上传文件失败");
            e.printStackTrace();
        } finally {
            if (ftpClient.isConnected()) {
                try {
                    ftpClient.disconnect();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != inputStream) {
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return true;
    }

    //改变目录路径
    public boolean changeWorkingDirectory(String directory) {
        boolean flag = true;
        try {
            flag = ftpClient.changeWorkingDirectory(directory);
            if (flag) {
                System.out.println("进入文件夹" + directory + " 成功！");

            } else {
                System.out.println("进入文件夹" + directory + " 失败！开始创建文件夹");
            }
        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
        return flag;
    }

    //创建多层目录文件，如果有ftp服务器已存在该文件，则不创建，如果无，则创建
    public boolean CreateDirecroty(String remote) throws IOException {
        boolean success = true;
        String directory = remote + "/";
        // 如果远程目录不存在，则递归创建远程服务器目录
        if (!directory.equalsIgnoreCase("/") && !changeWorkingDirectory(new String(directory))) {
            int start = 0;
            int end = 0;
            if (directory.startsWith("/")) {
                start = 1;
            } else {
                start = 0;
            }
            end = directory.indexOf("/", start);
            String path = "";
            String paths = "";
            while (true) {
                String subDirectory = new String(remote.substring(start, end).getBytes("GBK"), "iso-8859-1");
                path = path + "/" + subDirectory;
                if (!existFile(path)) {
                    if (makeDirectory(subDirectory)) {
                        changeWorkingDirectory(subDirectory);
                    } else {
                        System.out.println("创建目录[" + subDirectory + "]失败");
                        changeWorkingDirectory(subDirectory);
                    }
                } else {
                    changeWorkingDirectory(subDirectory);
                }

                paths = paths + "/" + subDirectory;
                start = end + 1;
                end = directory.indexOf("/", start);
                // 检查所有目录是否创建完毕
                if (end <= start) {
                    break;
                }
            }
        }
        return success;
    }

    //判断ftp服务器文件是否存在
    public boolean existFile(String path) throws IOException {
        boolean flag = false;
        FTPFile[] ftpFileArr = ftpClient.listFiles(path);
        if (ftpFileArr.length > 0) {
            flag = true;
        }
        return flag;
    }

    //创建目录
    public boolean makeDirectory(String dir) {
        boolean flag = true;
        try {
            flag = ftpClient.makeDirectory(dir);
            if (flag) {
                System.out.println("创建文件夹" + dir + " 成功！");

            } else {
                System.out.println("创建文件夹" + dir + " 失败！");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return flag;
    }

    /**
     * 下载文件 *
     *
     * @param pathname  FTP服务器文件目录 *
     * @param filename  文件名称 *
     * @param localpath 下载后的文件路径 *
     * @return
     */
    public boolean downloadFile(String pathname, String filename, String localpath) {
        boolean flag = false;
        OutputStream os = null;
        try {
            System.out.println("开始下载文件");
            initFtpClient();
            //切换FTP目录
            ftpClient.changeWorkingDirectory(pathname);
            FTPFile[] ftpFiles = ftpClient.listFiles();
            for (FTPFile file : ftpFiles) {
                if (filename.equalsIgnoreCase(file.getName())) {
                    File localFile = new File(localpath + "/" + file.getName());
                    os = new FileOutputStream(localFile);
                    ftpClient.retrieveFile(file.getName(), os);
                    os.close();
                }
            }
            ftpClient.logout();
            flag = true;
            System.out.println("下载文件成功");
        } catch (Exception e) {
            System.out.println("下载文件失败");
            e.printStackTrace();
        } finally {
            if (ftpClient.isConnected()) {
                try {
                    ftpClient.disconnect();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != os) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return flag;
    }

    /**
     * 删除文件 *
     *
     * @param pathname FTP服务器保存目录 *
     * @param filename 要删除的文件名称 *
     * @return
     */
    public boolean deleteFile(String pathname, String filename) {
        boolean flag = false;
        try {
            System.out.println("开始删除文件");
            initFtpClient();
            //切换FTP目录
            ftpClient.changeWorkingDirectory(pathname);
            ftpClient.dele(filename);
            ftpClient.logout();
            flag = true;
            System.out.println("删除文件成功");
        } catch (Exception e) {
            System.out.println("删除文件失败");
            e.printStackTrace();
        } finally {
            if (ftpClient.isConnected()) {
                try {
                    ftpClient.disconnect();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return flag;
    }

    public static void main(String[] args) throws FileNotFoundException {
        FTPUtils ftp = new FTPUtils();
        //ftp.uploadFile("www/images", "7.jpg", "C:/Users/admin/Desktop/sdtr/5.jpg");
        //ftp.downloadFile("ftpFile/data", "123.docx", "F://");
//        ftp.deleteFile("ftpFile/data", "123.docx");
        System.out.println("ok");
    }


}