利用apache ftp工具实现文件的上传下载和删除，具体如下
1、下载相应的jar包
commons-net-1.4.1.jar
2、实现代码如下：
public class FtpUtils { //ftp服务器地址 public String hostname = "192.168.1.249"; //ftp服务器端口号默认为21 public Integer port = 21 ; //ftp登录账号 public String username = "root"; //ftp登录密码 public String password = "123"; public FTPClient ftpClient = null; /** * 初始化ftp服务器 */ 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 * @param originfilename 待上传文件的名称（绝对地址） * * @return */ public boolean uploadFile( String pathname, String fileName,String originfilename){ boolean flag = false; InputStream inputStream = null; try{ System.out.println("开始上传文件"); inputStream = new FileInputStream(new File(originfilename)); 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) { FtpUtils ftp =new FtpUtils(); //ftp.uploadFile("ftpFile/data", "123.docx", "E://123.docx"); //ftp.downloadFile("ftpFile/data", "123.docx", "F://"); ftp.deleteFile("ftpFile/data", "123.docx"); System.out.println("ok"); } } 以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持武林网。