小知识——java实现FTP文件的上传、下载等操作

【本文将介绍java实现ftp文件的上传、下载、删除等操作】

本地搭建FTP服务器见：http://www.xitongcheng.com/jiaocheng/win7_article_38469.html

需要commons-net.jar，需要目标FTP服务器的ip、端口（默认21）、用户名、密码。

public class FtpUtil {
    private String ipAddr;
    private int port;
    private String userName;
    private String pwd;
	
    public FtpUtil(){super();}
    public FtpUtil(String ipAddr, int port, String userName, String pwd){
        this.ipAddr = ipAddr;
        this.port = port;
        this.userName = userName;
        this.pwd = pwd;
    }
	
    /**
     * 连接ftp ，成功返回FTPClient
     */
    public FTPClient connectFTP() {
        boolean success = false;
        FTPClient ftp = null;
        while (!success) {
            try {
                ftp = new FTPClient();
                ftp.setControlEncoding(\"UTF-8\");
                ftp.connect(ipAddr, port);
                FTPClientConfig conf = new FTPClientConfig(FTPClientConfig.SYST_NT);
                conf.setServerLanguageCode(\"zh\");
                ftp.login(userName, pwd);
                ftp.setFileType(FTPClient.BINARY_FILE_TYPE);
                int reply = ftp.getReplyCode();
                if (!FTPReply.isPositiveCompletion(reply)) {
                    ftp.disconnect();
                    success = false;
                }else{
                    success = true;
                }
                if(!success){
                    System.out.println(\"连接失败\");
                    Thread.sleep(3000);
                }
            } catch (SocketException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }  
        }
        System.out.println(\"连接成功\");
        return ftp;
    }
	
	
    /**
    * 创建目录
    * @param paths
    */
    private synchronized boolean markAndChangeDirectory(String paths , FTPClient ftp){
        boolean code = false;
        try {
            if(paths==null){
                paths =\"\";
            }
            String[] pathArrray = paths.split(\"/\");
            for(String path : pathArrray){
                if(!ftp.changeWorkingDirectory(path)){
                    ftp.makeDirectory(path);
                    ftp.changeWorkingDirectory(path);
                }
            }
            code = true;
        } catch (IOException e) {
            code = false;
        }
        return code;
    }
	
    /**
    * 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
    */
    //ftp.uploadFile(\"ftpFile/data\", \"123.docx\", \"E://123.docx\");
    public boolean uploadFile( String pathname, String fileName,String originfilename){
        InputStream inputStream = null;
        FTPClient ftp = null;
        try{
            inputStream = new FileInputStream(new File(originfilename));
            ftp = connectFTP();
            ftp.setFileType(FTP.BINARY_FILE_TYPE);
            markAndChangeDirectory(pathname,ftp);
            boolean code = ftp.storeFile(fileName, inputStream);
            inputStream.close();

            if(code){
                StringBuffer sb = new StringBuffer();
                sb.append(\"ftp://\");
                sb.append(userName).append(\":\").append(pwd).append(\"@\").append(ipAddr).append(\":\").append(port).append(ftp.printWorkingDirectory()+ \"/\" + fileName);
                System.out.println(\"文件地址：\"+sb);
                ftp.logout();
            }else{
                System.out.println(\"上传失败\");
                return false;
            }                    
        } catch (Exception e) {
            System.out.println(\"上传文件失败\");
            e.printStackTrace();
            return false;
        } finally{
            if(ftp.isConnected()){ 
                try{
                    ftp.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                }
            } 
            if(null != inputStream){
                try {
                    inputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                } 
            } 
        }
        return true;
    }
  
    /** 
    * 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 */
    //ftp.downloadFile(\"ftpFile/data\", \"123.docx\", \"E://\");
    public boolean downloadFile(String pathname, String filename, String localpath){ 
        FTPClient ftp = null;
        OutputStream os=null;
        try { 
            ftp = connectFTP();
            ftp.changeWorkingDirectory(pathname); 
            FTPFile[] ftpFiles = ftp.listFiles(); 
            for(FTPFile file : ftpFiles){ 
                if(filename.equalsIgnoreCase(file.getName())){ 
                    File localFile = new File(localpath + \"/\" + file.getName()); 
                    os = new FileOutputStream(localFile); 
                    ftp.retrieveFile(file.getName(), os); 
                    os.close(); 
                } 
            } 
            ftp.logout(); 
            System.out.println(\"下载文件成功\");
        } catch (Exception e) { 
            System.out.println(\"下载文件失败\");
            e.printStackTrace();
            return false;
        } finally{ 
            if(ftp.isConnected()){ 
                try{
                    ftp.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                }
            } 
            if(null != os){
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                } 
            } 
        } 
        return true; 
    }

    /** 
    * 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){  
        FTPClient ftp = null;
        try { 
            ftp = connectFTP();
            ftp.changeWorkingDirectory(pathname); 
            ftp.dele(filename); 
            ftp.logout();
            System.out.println(\"删除文件成功\");
        } catch (Exception e) { 
            System.out.println(\"删除文件失败\");
            e.printStackTrace();
            return false; 
        } finally {
            if(ftp.isConnected()){ 
                try{
                    ftp.disconnect();
                }catch(IOException e){
                    e.printStackTrace();
                }
            } 
        }
        return true; 
    }
	
    public String getIpAddr() {
        return ipAddr;
    }
    public void setIpAddr(String ipAddr) {
        this.ipAddr = ipAddr;
    }
    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 getPwd() {
        return pwd;
    }
    public void setPwd(String pwd) {
        this.pwd = pwd;
    }
}