基于commons-net实现ftp创建文件夹、上传、下载功能.

commons-net 概述 与 下载

1、Apache
官方说明地址：http://commons.apache.org/proper/commons-net/index.html
2、Apache 的 common-net 是 commos 顶级项目下一个非常强大的用于网络编程的子项目

FtpClientUtil

​ package com.demo.ftp;

import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.IOException;  
import java.io.InputStream;  
import java.io.OutputStream;  
import java.io.PrintWriter;  
import java.net.ConnectException;  

import org.apache.commons.net.PrintCommandListener;  
import org.apache.commons.net.ftp.FTP;  
import org.apache.commons.net.ftp.FTPClient;  
import org.apache.commons.net.ftp.FTPReply;  

/** 
 * @author oldlu 
 */  
public class FtpClientUtil {  
    /** 
     * ftp服务器地址 
     */  
    private  String server;  
    /** 
     * 端口 
     */  
    private  int port;  
    /** 
     * 用户名 
     */  
    private  String username;  
    /** 
     *  
     */  
    private  String password;  

    public FtpClientUtil () {  
        server = "localhost";  
        port = 21;  
        username = "kun";  
        password = "111111";  
    }  

    public FtpClientUtil(String server, int port, String username,  
            String password) {  
        this.server = server;  
        this.port = port;  
        this.username = username;  
        this.password = password;  
    }  
    /**上传文件 
     * @param remoteFileName 远程文件名称 
     * @param locaFileName 本地文件名称 
     */  
    public void upload(String remoteFileName,String locaFileName){  
        FTPClient ftp=null;   
        try {  
            ftp = new FTPClient();  
            ftp.addProtocolCommandListener( new PrintCommandListener( new PrintWriter( System.out ), true ) );  
            //连接ftp服务器  
            connect( ftp );  
            //设置属性  
            setProperty( ftp );  
            //上传文件  
            upload( ftp, remoteFileName, locaFileName );  
            //退出  
            logout( ftp );  
        } catch (Exception e) {  
            e.printStackTrace();  
        }finally {  
            if (ftp.isConnected()) {  
                try {  
                    ftp.disconnect();  
                } catch (IOException f) {  
                }  
            }  
        }  

    }  
    /**上传文件 
     * @param remoteFileName 远程文件名称 
     * @param locaFileName 本地文件名称 
     */  
    public void download(String remoteFileName,String locaFileName){  
        FTPClient ftp=null;   
        try {  
            ftp = new FTPClient();  
            ftp.addProtocolCommandListener( new PrintCommandListener( new PrintWriter( System.out ), true ) );  
            //连接ftp服务器  
            connect( ftp );  
            //设置属性  
            setProperty( ftp );  
            //下载文件  
            download( ftp, remoteFileName, locaFileName );  
            //退出  
            logout( ftp );  
        } catch (Exception e) {  
            e.printStackTrace();  
        }finally {  
            if (ftp.isConnected()) {  
                try {  
                    ftp.disconnect();  
                } catch (IOException f) {  
                }  
            }  
        }  
    }  
    /**创建文件夹 
     * @param remotePathName 远程文件夹名称 
     */  
    public void mkdir(String remotePathName) {  
        FTPClient ftp=null;   
        try {  
            ftp = new FTPClient();  
            ftp.addProtocolCommandListener( new PrintCommandListener( new PrintWriter( System.out ), true ) );  
            //连接ftp服务器  
            connect( ftp );  
            //设置属性  
            setProperty( ftp );  
            //创建文件夹  
            mkdir( ftp, remotePathName);  
            //退出  
            logout( ftp );  
        } catch (Exception e) {  
            e.printStackTrace();  
        }finally {  
            if (ftp.isConnected()) {  
                try {  
                    ftp.disconnect();  
                } catch (IOException f) {  
                }  
            }  
        }  
    }  
    /** 
     * @param ftp 
     * @param remotePathName 
     */  
    private void mkdir(FTPClient ftp, String remotePathName) throws Exception{  
        ftp.makeDirectory(remotePathName);  
    }  

    /** 
     * @param ftp 
     * @param remoteFileName 
     * @param locaFileName 
     */  
    private void download(FTPClient ftp, String remoteFileName,  
            String locaFileName) throws Exception{  
        OutputStream output=null;  
        output = new FileOutputStream(locaFileName);  
        ftp.retrieveFile(remoteFileName, output);   
        output.close();  
    }  

    /** 
     * @param ftp 
     * @throws Exception  
     */  
    private void setProperty(FTPClient ftp) throws Exception {  
        ftp.enterLocalPassiveMode();  
        //二进制传输,默认为ASCII  
        ftp.setFileType(FTP.BINARY_FILE_TYPE);  
    }  

    /** 
     * @param ftp 
     */  
    private void logout(FTPClient ftp) throws Exception{  
        ftp.noop();  
        ftp.logout();  
    }  

    /** 
     * @param ftp 
     * @param remoteFileName 
     * @param locaFileName 
     */  
    private void upload(FTPClient ftp, String remoteFileName,  
            String locaFileName) throws Exception{  
        //上传  
        InputStream input;  

        input = new FileInputStream(locaFileName);  

        ftp.storeFile(remoteFileName, input);  

        input.close();  
    }  

    /** 
     * @param ftp 
     */  
    private void connect(FTPClient ftp) throws Exception{  
        //连接服务器  
        ftp.connect( server, port);  
        int reply = ftp.getReplyCode();  
        //是否连接成功  
        if ( !FTPReply.isPositiveCompletion( reply ) )         {  
            throw new ConnectException( server+" 服务器拒绝连接" );  
        }  
        //登陆  
        if (!ftp.login(username, password)) {  
             throw new ConnectException( "用户名或密码错误" );  
        }  
    }  
}  </pre> 

FtpTest

​ package com.demo.ftp;

/** 
 * @author oldlu
 */  
public class FtpTest {  

    public static void main(String[] args) {  
        //上传文件  
        //upload();  
        //下载文件  
        //download();  
        //创建文件夹  
        mkdir();  
    }  

    /** 
     *  
     */  
    private static void mkdir() {  
        FtpClientUtil clientUtil=new FtpClientUtil();  
        clientUtil.mkdir("test");  
    }  

    /** 
     *  
     */  
    private static void download() {  
        String remoteFileName="./111.txt";  
        String locaFileName="F:\\test\\txt\\3333.txt";  
        FtpClientUtil clientUtil=new FtpClientUtil();  
        clientUtil.download(remoteFileName, locaFileName);  
    }  

    /** 
     *  
     */  
    private static void upload() {  
        String remoteFileName="./111.txt";  
        String locaFileName="F:\\test\\txt\\aaa.txt";  
        FtpClientUtil clientUtil=new FtpClientUtil();  
        clientUtil.upload(remoteFileName, locaFileName);  
    }  
}  </pre>