【FTP】java实现FTP服务上传下载

1、首先在pom文件中添加ftp相关依赖。

	
		
			commons-net
			commons-net
			3.3
		

2、代码库如下

package com.zero.service.impl;

import com.zero.Shift;
import com.zero.StatusCode;
import com.zero.config.FtpConfig;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;
import org.apache.commons.net.ftp.FTPReply;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.util.StringUtils;

import java.io.*;
import java.net.SocketException;

/**
 * Created by shuo on 2018/5/21.
 */
@Service("ftpService")
@Slf4j
public class FtpServiceImpl {

    public FTPClient ftpClient = null;
    public   FTPClient getFTPClient(String ftpHost, String ftpUserName,
                                         String ftpPassword, int ftpPort) throws SocketException,IOException {
        ftpClient = new FTPClient();
        ftpClient.setControlEncoding("utf-8");
        ftpClient.setDataTimeout(60000);       //设置传输超时时间为60秒
        ftpClient.setConnectTimeout(60000);       //连接超时为60秒
        try {
            ftpClient.connect(ftpHost, ftpPort);// 连接FTP服务器
            ftpClient.login(ftpUserName, ftpPassword);// 登陆FTP服务器
            if (!FTPReply.isPositiveCompletion(ftpClient.getReplyCode())) {
                log.error("未连接到FTP，用户名或密码错误。");
                ftpClient.disconnect();
            }
        } catch (SocketException e) {
            e.printStackTrace();
            throw new SocketException("FTP的IP地址可能错误，请正确配置。");
        } catch (IOException e) {
            e.printStackTrace();
            throw new SocketException("FTP的端口错误,请正确配置。");
        }
        return ftpClient;
    }


    /**
     * 上传文件
     * @param pathName ftp服务保存地址
     * @param fileName 上传到ftp的文件名
     *  @param originfilename 待上传文件的名称（绝对地址） *
     * @return
     */
    public boolean uploadFile(FTPClient ftpClient,String orgId, String pathName, String fileName,String originfilename) throws Exception {
        InputStream inputStream = new FileInputStream(new File(originfilename));
        return uploadFile(ftpClient,pathName,fileName,inputStream);
    }
    /**
     * 上传文件
     * @param realPathName ftp服务保存地址
     * @param uuidName 上传到ftp的文件名
     * @param inputStream 输入文件流
     * @return
     */
    public boolean uploadFile(FTPClient ftpClient,String realPathName, String uuidName,InputStream inputStream) throws Exception{
        boolean flag=false;
        try{
            this.ftpClient=ftpClient;
            ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
            createDirecroty(realPathName);
            ftpClient.makeDirectory(realPathName);
            ftpClient.changeWorkingDirectory(realPathName);
            ftpClient.storeFile(uuidName, inputStream);
            inputStream.close();
            ftpClient.logout();
            flag=true;
        }catch (Exception e) {
            e.printStackTrace();
            System.out.println("上传文件失败");
        }finally{
            if(ftpClient.isConnected()){
                try{
                    ftpClient.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                    throw new Exception("上传文件失败");
                }
            }

        }
        return flag;
    }
    //改变目录路径
    public boolean changeWorkingDirectory(String directory) throws Exception {
        boolean flag = true;
        try {
            //flag = getDefaultFtpClient().changeWorkingDirectory(directory);
            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();
            throw new Exception("改变目录路径失败");
        }
        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 Exception {
        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;
                System.out.println("***************");
                System.out.println("subDirectory:"+subDirectory);
                System.out.println("path:"+path);
                //false表示当前文件夹下没有文件
                if (!existFile(path)) {
                    System.out.println("path:"+path+";existFile");
                    if (makeDirectory(subDirectory)) {
                        System.out.println("path:"+path+";makeDirectory");
                        changeWorkingDirectory(subDirectory);
                        System.out.println("path:"+path+";changeWorkingDirectory");
                    } else {
                        System.out.println("创建目录[" + subDirectory + "]失败");
                        changeWorkingDirectory(subDirectory);
                    }
                } else {
                    System.out.println("path:"+path+";changeWorkingDirectory1");
                    changeWorkingDirectory(subDirectory);
                    System.out.println("path:"+path+";changeWorkingDirectory2");
                }

                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);
        //FTPFile[] ftpFileArr = getDefaultFtpClient().listFiles(path);
        if (ftpFileArr.length > 0) {
            flag = true;
        }
        return flag;
    }

    //创建目录
    public boolean makeDirectory(String dir) {
        boolean flag = true;
        try {
//            flag = getDefaultFtpClient().makeDirectory(dir);
            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(FTPClient ftpClient,String pathName, String fileName, OutputStream os) throws Exception{
        boolean flag;
        //OutputStream os=null;
        try {
            System.out.println("开始下载文件");
            this.ftpClient=ftpClient;
            //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) {
            e.printStackTrace();
            throw new Exception("下载文件失败");
        } finally{
            if(ftpClient.isConnected()){
                try{
                    ftpClient.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                    throw new Exception("下载文件失败");
                }
            }
            if(null != os){
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                    throw new Exception("下载文件失败");
                }
            }
        }
        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(FTPClient ftpClient,String pathName, String fileName) throws Exception{
        boolean flag;

        try {
            System.out.println("开始删除文件");
            this.ftpClient=ftpClient;
            //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) {
            e.printStackTrace();
            throw new Exception("删除文件失败");
        } finally {
            if(ftpClient.isConnected()){
                try{
                    ftpClient.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                    throw new Exception("删除文件失败");
                }
            }
        }
        return flag;
    }
}

3、客户端

       首先先获取FTPClient对象。然后就可以进行上传、下载、删除等操作啦。需要注意的是ftpclient不支持一次创建多级目录，因此需要通过迭代来创建多级目录。创建多级目录的时候需要保证是同一个对象。