Java 操作FTP服务器进行下载文件

用Java去操作FTP服务器去做下载，本文章里面分为单个下载和批量下载，批量下载只不过多了一层循环，为了方便参考，我代码都贴出来了。

不管单个下载还是多个，一定要记得，远程服务器的直接写文件夹路径，别加什么ftp://ip了

单个csv下载：

import org.apache.commons.io.FileUtils;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;import java.io.File;
import java.io.FileOutputStream;/*** Created by Administrator on 2018/8/29 0029.* FTP 工具类*/public class FTPUtil {/************************** 方案一 ****************************/public static void main(String[] args) {FTPUtil f = new FTPUtil();f.download();}public void download(){//进行下载文件---------------------------------开始//远程服务器下载地址//远程路径路径直接主要写，不用在前面加ip什么的，会报路径找不到的String fileurl = "/pub/himawari/L2/xxxx.csv";  //本地文件物理路径String realfilepath = "E:/xxxx.csv";//本地中新建文件夹目录System.out.println("存储路径realfilepath:" + realfilepath + "下载路径：" + fileurl);boolean bb = retepasvfile(realfilepath,fileurl,"xxxx.csv");}/*** 本地保存** @param localurl 本地文件物理路径* @param hosturl 远程服务器下载地址* @param filename 文件名称** @return*/public synchronized boolean retepasvfile(String localurl, String hosturl, String filename) {FTPClient ftp = new FTPClient();boolean re = false;try {System.out.println("本地存储路径==:" + localurl);File file = FileUtils.getFile(localurl);ftp.setConnectTimeout(10000);ftp.setDataTimeout(10000);ftp.connect("192.168.1.12", 21);ftp.login("username", "pwd");//ftp.bin();//  String str=ftp.pwd();ftp.enterLocalPassiveMode(); //被动模式ftp.setControlKeepAliveTimeout(60);ftp.setFileType(FTP.BINARY_FILE_TYPE);boolean b = ftp.changeWorkingDirectory(hosturl.substring(0, hosturl.lastIndexOf("/")));System.out.println("pwd：" + b + "---切换目录：" + hosturl.substring(0, hosturl.lastIndexOf("/")));long locationsize = file.length();//服务器上文件的大小if (b) {boolean res = false;res = ftp.retrieveFile(filename, new FileOutputStream(file));if (res) {//ftp.disconnect();System.out.println("文件下载完成");re = true;} else {System.out.println("文件下载失败");//ftp.disconnect();}}} catch (Exception e) {e.getStackTrace();System.out.println("retepasvfileSamba:e=3" + e);} finally {try {ftp.disconnect();} catch (Exception e) {}}return re;}/************************** 方案二 ****************************/public static void main(String[] args) {String server = "192.168.1.12";int port = 21;String username = "name";String password = "pwd";org.apache.commons.net.ftp.FTPClient ftpClient = new FTPClient();try {// 连接到FTP服务器ftpClient.connect(server, port);ftpClient.login(username, password);// 设置文件传输模式为二进制ftpClient.setFileType(FTP.BINARY_FILE_TYPE);// 下载文件从FTP服务器File fileToDownload = new File("ceshi/1111.xlsx");FileOutputStream outputStream = new FileOutputStream(fileToDownload,true);ftpClient.retrieveFile("E:\\1111.xlsx", outputStream);outputStream.close();// 断开连接ftpClient.logout();ftpClient.disconnect();System.out.println("文件上传和下载成功");} catch (Exception e) {e.printStackTrace();}}}

批量下载是基于第一个方案去做的：

import org.apache.commons.io.FileUtils;
import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPFile;import java.io.*;
import java.util.ArrayList;
import java.util.List;public class Text {/*public static void main(String[] args) {Text f = new Text();f.download();}*/public void download(){//进行下载文件---------------------------------开始//远程服务器下载地址String fileurl = "/pub/19/"; //远程目录//本地文件物理路径String realfilepath = "E:/excel采集"; //本地目录//本地中新建文件夹目录System.out.println("存储路径realfilepath:" + realfilepath + "下载路径：" + fileurl);boolean bb = retepasvfile(realfilepath,fileurl);}/*** 本地保存** @param localurl 本地文件物理路径* @param hosturl 远程服务器下载地址** @return*/public synchronized boolean retepasvfile(String localurl, String hosturl) {FTPClient ftp = new FTPClient();boolean re = false;try {System.out.println("本地存储路径==:" + localurl);File file = FileUtils.getFile(localurl);ftp.setConnectTimeout(10000);ftp.setDataTimeout(10000);ftp.connect("ftp.ptree.jaxa.jp", 21);ftp.login("fsr1812317746_gmail.com", "SP+wari8");//ftp.bin();//  String str=ftp.pwd();ftp.enterLocalPassiveMode(); //被动模式ftp.setControlKeepAliveTimeout(60);ftp.setFileType(FTP.BINARY_FILE_TYPE);boolean b = ftp.changeWorkingDirectory(hosturl.substring(0, hosturl.lastIndexOf("/")));System.out.println("pwd：" + b + "---切换目录：" + hosturl.substring(0, hosturl.lastIndexOf("/")));FTPFile[] ftpFiles = ftp.listFiles();System.out.println(ftpFiles.length);if (b) {boolean res = false;//唯一和单个下载改动的就是这里，去循环获取，然后单个下载，如果数量多的情况下，可以使用线程for (FTPFile ftpFile  : ftpFiles){res = ftp.retrieveFile(ftpFile.getName(), new FileOutputStream(file+"/"+ftpFile.getName()));if (res) {//ftp.disconnect();System.out.println(">>>>>> "+ftpFile.getName()+" 文件下载完成");re = true;} else {System.out.println("文件下载失败");//ftp.disconnect();}}}} catch (Exception e) {e.getStackTrace();System.out.println("retepasvfileSamba:e=3" + e);} finally {try {ftp.disconnect();} catch (Exception e) {}}return re;}}