Java实现FTP上传下载文件的工具包有很多，这里我采用Java自带的API，实现FTP上传下载文件。另外JDK1.7以前的版本与其之后版本的API有了较大的改变了。
例如：
| JDK1.7之前 | JDK1.7 |
| ftpClient = new FtpClinet() | ftpClient = FtpClient.create(ip) |
| ftpclient.login(user,password) | ftpclient.login(user,null,password) |
| ftpclient.binary() | ftpClient.setBinaryType(); |
一. 连接FTP服务器
1: public class FTPUtil {
2: //FTP服务器IP地址
3: public final static String FTP_HOST = "10.103.240.255";
4:
5: //FTP服务器端口
6: public final static int FTP_PORT = 21;
7:
8: //FTP服务器用户名
9: public final static String FTP_USER = "bloodHunter";
10:
11: //密码
12: public final static String FTP_PASSWORD = "wbljy";
13:
14:
15: public static FtpClient getConnect()
16: {
17: try {
18: FtpClient ftpClient = FtpClient.create(FTP_HOST);
19: ftpClient.login(FTP_USER, FTP_PASSWORD.toCharArray());
20: return ftpClient;
21: } catch (FtpProtocolException e) {
22: // TODO Auto-generated catch block
23: e.printStackTrace();
24: System.out.println("Connect to FTP Server fail!");
25: return null;
26: } catch (IOException e) {
27: // TODO Auto-generated catch block
28: e.printStackTrace();
29: System.out.println("Connect to FTP Server fail!");
30: return null;
31: }
32:
33: }
34: }
二. 上传文件
1: /*
2: * ftp file upload
3: * @param path 上传文件的路径
4: * @param fileName 上传文件名称
5: * @return 上传成功返回true,否则返回false
6: * */
7:
8: public static boolean FtpUpload(String path,String fileName)
9: {
10: TelnetOutputStream os = null;
11: FileInputStream is = null;
12: FtpClient ftpClient = getConnect();
13: try {
14: ftpClient.setBinaryType();
15: os = (TelnetOutputStream) ftpClient.putFileStream(fileName, true);
16: is = new FileInputStream(new File(path));
17: byte[] buffer = new byte[1024];
18: int c;
19: while((c = is.read(buffer)) != -1)
20: {
21: os.write(buffer,0,c);
22: }
23: System.out.println("Upload Success!");
24: return true;
25: } catch (Exception e) {
26: // TODO: handle exception
27: e.printStackTrace();
28: System.out.println("Upload fail!");
29: return false;
30: }finally{
31: try {
32: ftpClient.close();
33: is.close();
34: os.close();
35: } catch (IOException e) {
36: // TODO Auto-generated catch block
37: e.printStackTrace();
38: }
39: }
40: }
三. 下载文件
1: /*
2: * ftp file download
3: * @param path 下载文件的保存路径
4: * @param fileName 下载文件名称
5: * @return 下载成功返回true,否则返回false
6: * */
7: public static boolean FtpDownload(String path,String fileName)
8: {
9: FileInputStream is = null;
10: FileOutputStream os = null;
11: FtpClient ftpClient = getConnect();
12: try {
13: is = (FileInputStream) ftpClient.getFileStream(fileName);
14: os = new FileOutputStream(new File(path));
15: byte[] buffer = new byte[1024];
16: int c;
17: while((c = is.read(buffer)) != -1)
18: {
19: os.write(buffer,0,c);
20: }
21: System.out.println("Download Success!");
22: return true;
23: } catch (FtpProtocolException e) {
24: // TODO Auto-generated catch block
25: e.printStackTrace();
26: System.out.println("Download fail!");
27: return false;
28: } catch (IOException e) {
29: // TODO Auto-generated catch block
30: e.printStackTrace();
31: System.out.println("Download fail");
32: return false;
33: }catch (Exception e) {
34: // TODO: handle exception
35: e.printStackTrace();
36: return false;
37: }
38: finally{
39: try {
40: is.close();
41: os.close();
42: ftpClient.close();
43: } catch (IOException e) {
44: // TODO Auto-generated catch block
45: e.printStackTrace();
46: }
47: }
48: }
四. 遍历FTP目录文件
1: /*
2: * FTP getFileList
3: * @param filenames 保存遍历的文件名
4: * @param path 遍历目录的路径
5: * */
6: public static void getFtpFileList(List<String> filenames,String path){
7: //DataInputStream ds = null;
8: BufferedReader ds = null;
9: FtpClient ftpClient = getConnect();
10: try {
11: ds = new BufferedReader(new InputStreamReader(ftpClient.nameList(path),"ISO-8859-1"));
12: String line = "";
13: while((line = ds.readLine())!=null){
14: line = new String(line.getBytes("ISO-8859-1"),"GBK");
15: String name[] = line.split("/");
16: filenames.add(name[name.length - 1]);
17: }
18: } catch (FtpProtocolException e) {
19: // TODO Auto-generated catch block
20: e.printStackTrace();
21: } catch (IOException e) {
22: // TODO Auto-generated catch block
23: e.printStackTrace();
24: }finally{
25: try {
26: ds.close();
27: ftpClient.close();
28: } catch (IOException e) {
29: // TODO Auto-generated catch block
30: e.printStackTrace();
31: }
32: }
33: }