Android使用ftp方式實現文件上傳和下載

近期在工作上一直再維護平臺OTA在線升級項目，其中關於這個升級文件主要是存放於ftp服務器上的，然後客戶端通過走ftp協議方式下載至本地Android機進行一個系統升級操作。那麼今天將對ftp實現文件上傳和下載進行一個使用總結，關於ftp這方面的理論知識如果不是太瞭解的各位道友，那麼請移步HTTP和FTP的區別的一些理論知識 作個具體的瞭解或者查閱相關資料。那麼先看看個人工作項目這個OTA升級效果圖吧。如下：

下面是具體的接口實現：

那麼相關ftp的操作，已經被封裝到ota.ftp這個包下，各位童鞋可以下載示例代碼慢慢研究。另外這個要是用ftp服務我們cline端需要再項目工程導入ftp4j-1.7.2.jar包

這邊作個使用的邏輯分析：首先在我們的項目工程FtpApplication中啓動這個OtaService，其中OtaService作爲一個服務運行起來，在這個服務裏面拿到封裝好ftp相關接口的DownLoad.java進行ftp文件操作，關鍵代碼如下：

public void startDownload() {
        // TODO Auto-generated method stub
        mDownLoad.start();
    }

    public void stopDownload() {
        mDownLoad.stop();
    }

    public void cancel() {
        mDownLoad.cancel();
    }

    public String getOldDate() {
        return mDownLoad.getDatabaseOldDate();
    }

    public String getOldVersion() {
        return mDownLoad.getDatabaseOldVersion();
    }

    public void checkVer(String serverRoot) {
        // TODO Auto-generated method stub
        mDownLoad = DownLoad.getInstance();
        mDownLoad.setServeRoot(serverRoot);
        mDownLoad.setFtpInfo(mApp.mFtpInfo);
        mDownLoad.checkUpgrade();
    }

FTPToolkit.java

package com.asir.ota.ftp;


import it.sauronsoftware.ftp4j.FTPClient; 
import it.sauronsoftware.ftp4j.FTPFile;

import java.io.File;
import java.util.List;

import com.asir.ota.clinet.PathToolkit;
import com.asir.ota.ftp.DownLoad.MyFtpListener;

/**
 * FTP客戶端工具
 * 
 */
public final class FTPToolkit {

    private FTPToolkit() {
    }

    /**
     * 創建FTP連接
     * 
     * @param host
     *            主機名或IP
     * @param port
     *            ftp端口
     * @param username
     *            ftp用戶名
     * @param password
     *            ftp密碼
     * @return 一個客戶端
     * @throws Exception 
     */
    public static FTPClient makeFtpConnection(String host, int port,
            String username, String password) throws Exception {
        FTPClient client = new FTPClient();
        try {
            client.connect(host, port);
            if(username != null && password != null) {
                client.login(username, password);
            }
        } catch (Exception e) {
            throw new Exception(e);
        }
        return client;
    }
/**
     * FTP下載文件到本地一個文件夾,如果本地文件夾不存在，則創建必要的目錄結構
     * 
     * @param client
     *            FTP客戶端
     * @param remoteFileName
     *            FTP文件
     * @param localPath
     *            存的本地文件路徑或目錄
     * @throws Exception 
     */
    public static void download(FTPClient client, String remoteFileName,
            String localPath, long startPoint, MyFtpListener listener) throws Exception {

        String localfilepath = localPath;
        int x = isExist(client, remoteFileName);
        File localFile = new File(localPath);
        if (localFile.isDirectory()) {
            if (!localFile.exists())
                localFile.mkdirs();
            localfilepath = PathToolkit.formatPath4File(localPath
                    + File.separator + new File(remoteFileName).getName());
        }

        if (x == FTPFile.TYPE_FILE) {
            try {
                if (listener != null)
                    client.download(remoteFileName, new File(localfilepath),
                            startPoint, listener);
                else
                    client.download(remoteFileName, new File(localfilepath), startPoint);
            } catch (Exception e) {
                throw new Exception(e);
            }
        } else {
            throw new Exception("the target " + remoteFileName + "not exist");
        }
    }
/**
     * FTP上傳本地文件到FTP的一個目錄下
     * 
     * @param client
     *            FTP客戶端
     * @param localfile
     *            本地文件
     * @param remoteFolderPath
     *            FTP上傳目錄
     * @throws Exception 
     */
    public static void upload(FTPClient client, File localfile,
            String remoteFolderPath, MyFtpListener listener) throws Exception {
        remoteFolderPath = PathToolkit.formatPath4FTP(remoteFolderPath);
        try {
            client.changeDirectory(remoteFolderPath);
            if (!localfile.exists())
                throw new Exception("the upload FTP file"
                        + localfile.getPath() + "not exist!");
            if (!localfile.isFile())
                throw new Exception("the upload FTP file"
                        + localfile.getPath() + "is a folder!");
            if (listener != null)
                client.upload(localfile, listener);
            else
                client.upload(localfile);
            client.changeDirectory("/");
        } catch (Exception e) {
            throw new Exception(e);
        }
    }

/**
     * FTP上傳本地文件到FTP的一個目錄下
     * 
     * @param client
     *            FTP客戶端
     * @param localfilepath
     *            本地文件路徑
     * @param remoteFolderPath
     *            FTP上傳目錄
     * @throws Exception 
     */
    public static void upload(FTPClient client, String localfilepath,
            String remoteFolderPath, MyFtpListener listener) throws Exception {
        File localfile = new File(localfilepath);
        upload(client, localfile, remoteFolderPath, listener);
    }

/**
     * 批量上傳本地文件到FTP指定目錄上
     * 
     * @param client
     *            FTP客戶端
     * @param localFilePaths
     *            本地文件路徑列表
     * @param remoteFolderPath
     *            FTP上傳目錄
     * @throws Exception 
     */
    public static void uploadListPath(FTPClient client,
            List<String> localFilePaths, String remoteFolderPath, MyFtpListener listener) throws Exception {
        remoteFolderPath = PathToolkit.formatPath4FTP(remoteFolderPath);
        try {
            client.changeDirectory(remoteFolderPath);
            for (String path : localFilePaths) {
                File file = new File(path);
                if (!file.exists())
                    throw new Exception("the upload FTP file" + path + "not exist!");
                if (!file.isFile())
                    throw new Exception("the upload FTP file" + path
                            + "is a folder!");
                if (listener != null)
                    client.upload(file, listener);
                else
                    client.upload(file);
            }
            client.changeDirectory("/");
        } catch (Exception e) {
            throw new Exception(e);
        }
    }
/**
     * 批量上傳本地文件到FTP指定目錄上
     * 
     * @param client
     *            FTP客戶端
     * @param localFiles
     *            本地文件列表
     * @param remoteFolderPath
     *            FTP上傳目錄
     * @throws Exception 
     */
    public static void uploadListFile(FTPClient client, List<File> localFiles,
            String remoteFolderPath, MyFtpListener listener) throws Exception {
        try {
            client.changeDirectory(remoteFolderPath);
            remoteFolderPath = PathToolkit.formatPath4FTP(remoteFolderPath);
            for (File file : localFiles) {
                if (!file.exists())
                    throw new Exception("the upload FTP file" + file.getPath()
                            + "not exist!");
                if (!file.isFile())
                    throw new Exception("the upload FTP file" + file.getPath()
                            + "is a folder!");
                if (listener != null)
                    client.upload(file, listener);
                else
                    client.upload(file);
            }
            client.changeDirectory("/");
        } catch (Exception e) {
            throw new Exception(e);
        }
    }
/**
     * 判斷一個FTP路徑是否存在，如果存在返回類型(FTPFile.TYPE_DIRECTORY=1、FTPFile.TYPE_FILE=0、
     * FTPFile.TYPE_LINK=2) 如果文件不存在，則返回一個-1
     * 
     * @param client
     *            FTP客戶端
     * @param remotePath
     *            FTP文件或文件夾路徑
     * @return 存在時候返回類型值(文件0，文件夾1，連接2)，不存在則返回-1
     */
    public static int isExist(FTPClient client, String remotePath) {
        remotePath = PathToolkit.formatPath4FTP(remotePath);
        FTPFile[] list = null;
        try {
            list = client.list(remotePath);
        } catch (Exception e) {
            return -1;
        }
        if (list.length > 1)
            return FTPFile.TYPE_DIRECTORY;
        else if (list.length == 1) {
            FTPFile f = list[0];
            if (f.getType() == FTPFile.TYPE_DIRECTORY)
                return FTPFile.TYPE_DIRECTORY;
            // 假設推理判斷
            String _path = remotePath + "/" + f.getName();
            try {
                int y = client.list(_path).length;
                if (y == 1)
                    return FTPFile.TYPE_DIRECTORY;
                else
                    return FTPFile.TYPE_FILE;
            } catch (Exception e) {
                return FTPFile.TYPE_FILE;
            }
        } else {
            try {
                client.changeDirectory(remotePath);
                return FTPFile.TYPE_DIRECTORY;
            } catch (Exception e) {
                return -1;
            }
        }
    }
public static long getFileLength(FTPClient client, String remotePath) throws Exception {
        String remoteFormatPath = PathToolkit.formatPath4FTP(remotePath);
        if(isExist(client, remotePath) == 0) {
            FTPFile[] files = client.list(remoteFormatPath);
            return files[0].getSize();

        }else {
            throw new Exception("get remote file length error!");
        }
    }

    /**
     * 關閉FTP連接，關閉時候像服務器發送一條關閉命令
     * 
     * @param client
     *            FTP客戶端
     * @return 關閉成功，或者鏈接已斷開，或者鏈接爲null時候返回true，通過兩次關閉都失敗時候返回false
     */

    public static boolean closeConnection(FTPClient client) {
        if (client == null)
            return true;
        if (client.isConnected()) {
            try {
                client.disconnect(true);
                return true;
            } catch (Exception e) {
                try {
                    client.disconnect(false);
                } catch (Exception e1) {
                    e1.printStackTrace();
                    return false;
                }
            }
        }
        return true;
    }
}

包括登錄，開始下載，取消下載，獲取升級文件版本號和服務器版本校驗等。其它的是一些數據庫，SD卡文件相關操作，那麼最後在我們下載完成之後需要對文件進行一個文件解壓再執行升級操作，這部分在ZipExtractor.java和OTAProvider.java中實現

示例代碼點擊下載