2019独角兽企业重金招聘Python工程师标准>>> 
本文利用apache ftpserver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");
}
}