上传文件到ftp 并下载，或删除

 import org.apache.commons.net.ftp.FTPClient;import org.apache.commons.net.ftp.FTPReply;import java.io.File;import java.io.FileInputStream;import java.io.IOException;/** * Created by wangyanlong on 2017/4/19. */public class FTPUtils {    private FTPClient ftp;    private String addrress;    private int port;    private String username;    private String password;    private String path;   //上传到ftp下面的那个路径下面    public FTPUtils(String addrress, int port, String username, String password, String path) {        this.addrress = addrress;        this.password = password;        this.username = username;        this.path = path;        this.port = port;    }    public FTPUtils() {    }    public static FTPUtils ftpUtils = null;    public static FTPUtils getInstance() {        if (ftpUtils == null) {            synchronized (FTPUtils.class) {                if (ftpUtils == null) {                    ftpUtils = new FTPUtils();                }            }        }        return ftpUtils;    }
/** * 下载文件 * * @param path * @return */public boolean dowinFile(String path, String filename) {    boolean bool = false;    OutputStream outputStream = null;    try {        String localPath = System.getProperty("user.home") + "\\Downloads\\";        this.connect();        System.out.println("链接成功！");        ftp.changeWorkingDirectory(path);//切换到当前目录        System.out.println("切换目录是否成功" + true);        FTPFile[] files = ftp.listFiles(path + "\\" + filename);        for (FTPFile f : files) {            if (filename.equals(f.getName())) {                System.out.println("本地下载路径：" + localPath + filename);                outputStream = new FileOutputStream(localPath + filename);                bool = ftp.retrieveFile(f.getName(), outputStream);            }        }        System.out.println("下载是否成功：" + bool);    } catch (IOException e) {        e.printStackTrace();    } finally {        try {            outputStream.close();            this.destroy();        } catch (IOException e) {            e.printStackTrace();        }    }    return bool;}
/** * 删除文件 * * @param path * @return */public boolean removeFile(String path) {    boolean bool=false;    try {       bool= ftp.deleteFile(path);    } catch (IOException e) {        e.printStackTrace();    }    return  bool;}
    /**
     * @param file 上传
     * @throws Exception
     */
    public void ftpUpload(File file, String dir) throws Exception {
        this.connect(dir);//获取链接
        //创需要的文件夹
        if (dir != null) {
            ftp.makeDirectory(dir);
            ftp.changeWorkingDirectory(dir);
        }
        this.uploadFile(file);

        this.destroy();
    }


    /**
     * 链接ftp
     *
     * @param dir
     * @throws IOException
     */
    public void connect(String dir) throws IOException {
        ftp = new FTPClient();
        ftp.connect(addrress, port);
        ftp.login(username, password);
        ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
        int reply;
        reply = ftp.getReplyCode();
        if (!FTPReply.isPositiveCompletion(reply)) {
            ftp.disconnect();
        }
        ftp.changeWorkingDirectory(path);

    }

    //真正上传文件
    public void uploadFile(File file) throws IOException {
        if (file.isDirectory()) {
            ftp.makeDirectory(file.getName());
            ftp.changeWorkingDirectory(file.getName());
            File[] files = file.listFiles();
            for (File f : files) {
                uploadFile(f);
                if (f.isDirectory()) {
                    ftp.changeToParentDirectory();
                }
            }
        } else {
            FileInputStream input = new FileInputStream(file);
            boolean result = ftp.storeFile(file.getName(), input);
            ftp.setDataTimeout(1200);
            System.out.println(result);
            input.close();
        }
    }

    public void destroy() throws IOException {
        if (ftp != null) {
            ftp.disconnect();
            ftp = null;
        }
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public String getAddrress() {
        return addrress;
    }

    public void setAddrress(String addrress) {
        this.addrress = addrress;
    }

    public int getPort() {
        return port;
    }

    public void setPort(int port) {
        this.port = port;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public static void main(String[] args) throws Exception {

        FTPUtils t = new FTPUtils();

        t.setAddrress("");
        t.setPort(21);
        t.setUsername("");
        t.setPassword("");
        t.setPath("\\");

        File file = new File("F:\\file\\ddd\\");
        t.ftpUpload(file, "FF");
    }


}