JAVA技术实现上传下载文件到FTP服务器(完整)

具体详细介绍请看下文：

在使用文件进行交互数据的应用来说，使用FTP服务器是一个很好的选择。本文使用Apache Jakarta Commons Net（commons-net-3.3.jar） 基于FileZilla Server服务器实现FTP服务器上文件的上传/下载/删除等操作。

关于FileZilla Server服务器的详细搭建配置过程，详情请见 FileZilla Server安装配置教程 。之前有朋友说，上传大文件（几百M以上的文件）到FTP服务器时会重现无法重命名的问题，但本人亲测上传2G的文件到FileZilla Server都没有该问题，朋友们可以放心使用该代码。

FavFTPUtil.Java

package com.favccxx.favsoft.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

public class FavFTPUtil {
 
 
 public static boolean uploadFile(String hostname, int port, String username, String password, String pathname, String fileName, InputStream inputStream){
 boolean flag = false;
 FTPClient ftpClient = new FTPClient();
 ftpClient.setControlEncoding("UTF-8");
 try {
 //连接FTP服务器
 ftpClient.connect(hostname, port);
 //登录FTP服务器
 ftpClient.login(username, password);
 //是否成功登录FTP服务器
 int replyCode = ftpClient.getReplyCode();
 if(!FTPReply.isPositiveCompletion(replyCode)){
 return flag;
 }
 
 ftpClient.setFileType(FTPClient.BINARY_FILE_TYPE);
 ftpClient.makeDirectory(pathname);
 ftpClient.changeWorkingDirectory(pathname);
 ftpClient.storeFile(fileName, inputStream);
 inputStream.close();
 ftpClient.logout();
 flag = true;
 } catch (Exception e) {
 e.printStackTrace();
 } finally{
 if(ftpClient.isConnected()){
 try {
 ftpClient.disconnect();
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 }
 return flag;
 }
 
 
 
 public static boolean uploadFileFromProduction(String hostname, int port, String username, String password, String pathname, String filename, String originfilename){
 boolean flag = false;
 try {
 InputStream inputStream = new FileInputStream(new File(originfilename));
 flag = uploadFile(hostname, port, username, password, pathname, filename, inputStream); 
 } catch (Exception e) {
 e.printStackTrace();
 }
 return flag;
 }
 
 
 public static boolean uploadFileFromProduction(String hostname, int port, String username, String password, String pathname, String originfilename){
 boolean flag = false;
 try {
 String fileName = new File(originfilename).getName();
 InputStream inputStream = new FileInputStream(new File(originfilename));
 flag = uploadFile(hostname, port, username, password, pathname, fileName, inputStream); 
 } catch (Exception e) {
 e.printStackTrace();
 }
 return flag;
 }
 
 
 
 public static boolean deleteFile(String hostname, int port, String username, String password, String pathname, String filename){
 boolean flag = false;
 FTPClient ftpClient = new FTPClient();
 try {
 //连接FTP服务器
 ftpClient.connect(hostname, port);
 //登录FTP服务器
 ftpClient.login(username, password);
 //验证FTP服务器是否登录成功
 int replyCode = ftpClient.getReplyCode();
 if(!FTPReply.isPositiveCompletion(replyCode)){
 return flag;
 }
 //切换FTP目录
 ftpClient.changeWorkingDirectory(pathname);
 ftpClient.dele(filename);
 ftpClient.logout();
 flag = true;
 } catch (Exception e) {
 e.printStackTrace();
 } finally{
 if(ftpClient.isConnected()){
 try {
 ftpClient.logout();
 } catch (IOException e) {
 
 }
 }
 }
 return flag;
 }
 
 
 public static boolean downloadFile(String hostname, int port, String username, String password, String pathname, String filename, String localpath){
 boolean flag = false;
 FTPClient ftpClient = new FTPClient();
 try {
 //连接FTP服务器
 ftpClient.connect(hostname, port);
 //登录FTP服务器
 ftpClient.login(username, password);
 //验证FTP服务器是否登录成功
 int replyCode = ftpClient.getReplyCode();
 if(!FTPReply.isPositiveCompletion(replyCode)){
 return flag;
 }
 //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());
 OutputStream os = new FileOutputStream(localFile);
 ftpClient.retrieveFile(file.getName(), os);
 os.close();
 }
 }
 ftpClient.logout();
 flag = true;
 } catch (Exception e) {
 e.printStackTrace();
 } finally{
 if(ftpClient.isConnected()){
 try {
 ftpClient.logout();
 } catch (IOException e) {
 
 }
 }
 }
 return flag;
 }

}
FavFTPUtilTest.java

package com.favccxx.favsoft.util;

import junit.framework.TestCase;

public class FavFTPTest extends TestCase {
 
 public void testFavFTPUtil(){
 String hostname = "127.0.0.1";
 int port = 21;
 String username = "business";
 String password = "business";
 String pathname = "business/ebook"; 
 String filename = "big.rar"; 
 String originfilename = "C:\Users\Downloads\Downloads.rar";
 FavFTPUtil.uploadFileFromProduction(hostname, port, username, password, pathname, filename, originfilename);
// String localpath = "D:/";
 
// FavFTPUtil.downloadFile(hostname, port, username, password, pathname, filename, localpath);
 }

}

以上就是JAVA通过FTP上传下载文件的完整代码，希望对大家有所帮助。