檔案操作相關（SD讀取，byte轉化，上傳等）：

public class FileUtil {
    private static String TAG = "FileUtil";
    /** 預設下載檔案地址. */
    public static String downPathRootDir = File.separator + "download" + File.separator;
    /** 預設下載圖片檔案地址. */
    public static String downPathImageDir = File.separator + "download" + File.separator + "cache_images"
 

            + File.separator;
    /** 預設下載檔案地址. */
    public static String downPathFileDir = File.separator + "download" + File.separator + "cache_files"
            + File.separator;

    /**
     * 下載網路檔案到SD卡中.如果SD中存在同名檔案將不再下載
     * 
     * @param url
     *            要下載檔案的網路地址
     * @return 下載好的本地檔案地址
     */
 

    public static String downFileToSD(String url) {
        InputStream in = null;
        FileOutputStream fileOutputStream = null;
        HttpURLConnection con = null;
        String downFilePath = null;
        try {
            if (!isCanUseSD()) {
                return null;
            }
            File path = Environment.getExternalStorageDirectory();
            File fileDirectory = new
 
 File(path.getAbsolutePath() + downPathImageDir);
            if (!fileDirectory.exists()) {
                fileDirectory.mkdirs();
            }
            File f = new File(fileDirectory, getFileNameFromUrl(url));
            if (!f.exists()) {
                f.createNewFile();
            } else {
                // 檔案已經存在
                if (f.length() != 0) {
                    return f.getPath();
                }
            }
            downFilePath = f.getPath();
            URL mUrl = new URL(url);
            con = (HttpURLConnection) mUrl.openConnection();
            con.connect();
            in = con.getInputStream();
            fileOutputStream = new FileOutputStream(f);
            byte[] b = new byte[1024];
            int temp = 0;
            while ((temp = in.read(b)) != -1) {
                fileOutputStream.write(b, 0, temp);
            }
        } catch (Exception e) {
            if (D)
                Log.d(TAG, "" + e.getMessage());
            return null;
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                if (fileOutputStream != null) {
                    fileOutputStream.close();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            try {
                if (con != null) {
                    con.disconnect();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return downFilePath;
    }

    /**
     * 描述：通過檔案的網路地址從SD卡中讀取圖片，如果SD中沒有則自動下載並儲存.
     * 
     * @param url
     *            檔案的網路地址
     * @param type
     *            圖片的處理型別（剪下或者縮放到指定大小，參考AbConstant類）
     * @param newWidth
     *            新圖片的寬
     * @param newHeight
     *            新圖片的高
     * @return Bitmap 新圖片
     */
    public static Bitmap getBitmapFromSDCache(String url, int type, int newWidth, int newHeight) {
        Bitmap bit = null;
        try {
            // SD卡是否存在
            if (!isCanUseSD()) {
                bit = getBitmapFormURL(url, type, newWidth, newHeight);
                return bit;
            }
            // 檔案是否存在
            File path = Environment.getExternalStorageDirectory();
            File fileDirectory = new File(path.getAbsolutePath() + downPathImageDir);
            File f = new File(fileDirectory, getFileNameFromUrl(url));
            if (!f.exists()) {
                downFileToSD(url);
                return getBitmapFromSD(f, type, newWidth, newHeight);
            } else {
                if (D)
                    Log.d(TAG, "要獲取的圖片路徑為：" + f.getPath());
                // 檔案存在
                if (type == AppConstant.CUTIMG) {
                    bit = ImageUtil.cutImg(f, newWidth, newHeight);
                } else {
                    bit = ImageUtil.scaleImg(f, newWidth, newHeight);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bit;

    }

    /**
     * 描述：通過檔案的網路地址從SD卡中讀取圖片.
     * 
     * @param url
     *            檔案的網路地址
     * @param type
     *            圖片的處理型別（剪下或者縮放到指定大小，參考AbConstant類）
     * @param newWidth
     *            新圖片的寬
     * @param newHeight
     *            新圖片的高
     * @return Bitmap 新圖片
     */
    public static Bitmap getBitmapFromSD(String url, int type, int newWidth, int newHeight) {
        Bitmap bit = null;
        try {
            // SD卡是否存在
            if (!isCanUseSD()) {
                return null;
            }
            // 檔案是否存在
            File path = Environment.getExternalStorageDirectory();
            File fileDirectory = new File(path.getAbsolutePath() + downPathImageDir);
            File f = new File(fileDirectory, getFileNameFromUrl(url));
            if (!f.exists()) {
                return null;
            } else {
                // 檔案存在
                if (type == AppConstant.CUTIMG) {
                    bit = ImageUtil.cutImg(f, newWidth, newHeight);
                } else {
                    bit = ImageUtil.scaleImg(f, newWidth, newHeight);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bit;

    }

    /**
     * 描述：通過檔案的本地地址從SD卡讀取圖片.
     *
     * @param file
     *            the file
     * @param type
     *            圖片的處理型別（剪下或者縮放到指定大小，參考AbConstant類）
     * @param newWidth
     *            新圖片的寬
     * @param newHeight
     *            新圖片的高
     * @return Bitmap 新圖片
     */
    public static Bitmap getBitmapFromSD(File file, int type, int newWidth, int newHeight) {
        Bitmap bit = null;
        try {
            // SD卡是否存在
            if (!isCanUseSD()) {
                return null;
            }
            // 檔案是否存在
            if (!file.exists()) {
                return null;
            }
            // 檔案存在
            if (type == AppConstant.CUTIMG) {
                bit = ImageUtil.cutImg(file, newWidth, newHeight);
            } else {
                bit = ImageUtil.scaleImg(file, newWidth, newHeight);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return bit;
    }

    /**
     * 描述：將圖片的byte[]寫入本地檔案.
     * 
     * @param imgByte
     *            圖片的byte[]形勢
     * @param fileName
     *            檔名稱，需要包含字尾，如.jpg
     * @param type
     *            圖片的處理型別（剪下或者縮放到指定大小，參考AbConstant類）
     * @param newWidth
     *            新圖片的寬
     * @param newHeight
     *            新圖片的高
     * @return Bitmap 新圖片
     */
    public static Bitmap getBitmapFormByte(byte[] imgByte, String fileName, int type, int newWidth, int newHeight) {
        FileOutputStream fos = null;
        DataInputStream dis = null;
        ByteArrayInputStream bis = null;
        Bitmap b = null;
        try {
            if (imgByte != null) {
                File sdcardDir = Environment.getExternalStorageDirectory();
                String path = sdcardDir.getAbsolutePath() + downPathImageDir;
                File file = new File(path + fileName);

                if (!file.getParentFile().exists()) {
                    file.getParentFile().mkdirs();
                }
                if (!file.exists()) {
                    file.createNewFile();
                }
                fos = new FileOutputStream(file);
                int readLength = 0;
                bis = new ByteArrayInputStream(imgByte);
                dis = new DataInputStream(bis);
                byte[] buffer = new byte[1024];

                while ((readLength = dis.read(buffer)) != -1) {
                    fos.write(buffer, 0, readLength);
                    try {
                        Thread.sleep(500);
                    } catch (Exception e) {
                    }
                }
                fos.flush();
            }
            b = getBitmapFormURL("/" + fileName, type, newWidth, newHeight);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (dis != null) {
                try {
                    dis.close();
                } catch (Exception e) {
                }
            }
            if (bis != null) {
                try {
                    bis.close();
                } catch (Exception e) {
                }
            }
            if (fos != null) {
                try {
                    fos.close();
                } catch (Exception e) {
                }
            }
        }
        return b;
    }

    /**
     * 描述：根據URL從互連網獲取圖片.
     * 
     * @param url
     *            要下載檔案的網路地址
     * @param type
     *            圖片的處理型別（剪下或者縮放到指定大小，參考AbConstant類）
     * @param newWidth
     *            新圖片的寬
     * @param newHeight
     *            新圖片的高
     * @return Bitmap 新圖片
     */
    public static Bitmap getBitmapFormURL(String url, int type, int newWidth, int newHeight) {
        Bitmap bit = null;
        try {
            bit = ImageUtil.getBitmapFormURL(url, type, newWidth, newHeight);
        } catch (Exception e) {
            if (D)
                Log.d(TAG, "下載圖片異常：" + e.getMessage());
        }
        if (D)
            Log.d(TAG, "返回的Bitmap：" + bit);
        return bit;
    }

    /**
     * 描述：獲取src中的圖片資源.
     *
     * @param src
     *            圖片的src路徑，如（“image/arrow.png”）
     * @return Bitmap 圖片
     */
    public static Bitmap getBitmapFormSrc(String src) {
        Bitmap bit = null;
        try {
            bit = BitmapFactory.decodeStream(FileUtil.class.getResourceAsStream(src));
        } catch (Exception e) {

            if (D)
                Log.d(TAG, "獲取圖片異常：" + e.getMessage());
        }
        if (D)
            Log.d(TAG, "返回的Bitmap：" + bit);
        return bit;
    }

    /**
     * 描述：獲取網路檔案的大小.
     *
     * @param Url
     *            圖片的網路路徑
     * @return int 網路檔案的大小
     */
    public static int getContentLengthFormUrl(String Url) {
        int mContentLength = 0;
        try {
            URL url = new URL(Url);
            HttpURLConnection mHttpURLConnection = (HttpURLConnection) url.openConnection();
            mHttpURLConnection.setConnectTimeout(5 * 1000);
            mHttpURLConnection.setRequestMethod("GET");
            mHttpURLConnection.setRequestProperty("Accept",
                    "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");
            mHttpURLConnection.setRequestProperty("Accept-Language", "zh-CN");
            mHttpURLConnection.setRequestProperty("Referer", Url);
            mHttpURLConnection.setRequestProperty("Charset", "UTF-8");
            mHttpURLConnection.setRequestProperty("User-Agent",
                    "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
            mHttpURLConnection.setRequestProperty("Connection", "Keep-Alive");
            mHttpURLConnection.connect();
            if (mHttpURLConnection.getResponseCode() == 200) {
                // 根據響應獲取檔案大小
                mContentLength = mHttpURLConnection.getContentLength();
            }
        } catch (Exception e) {
            e.printStackTrace();
            if (D)
                Log.d(TAG, "獲取長度異常：" + e.getMessage());
        }
        return mContentLength;
    }

    /**
     * HTTP檔案上傳.
     *
     * @param actionUrl
     *            要使用的URL
     * @param params
     *            表單引數
     * @param files
     *            要上傳的檔案列表
     * @return http返回的結果 或http響應碼
     * @throws com.bslee.MeSport.global.AppException
     *             the ab app exception
     */
    public static String postFile(String actionUrl, HashMap<String, String> params, HashMap<String, File> files)
            throws AppException {
        // 標識每個檔案的邊界
        String BOUNDARY = java.util.UUID.randomUUID().toString();
        String PREFIX = "--";
        String LINEND = "\r\n";
        String MULTIPART_FROM_DATA = "multipart/form-data";
        String CHARSET = "UTF-8";
        HttpURLConnection conn = null;
        DataOutputStream outStream = null;
        String retStr = "200";
        try {
            URL uri = new URL(actionUrl);
            conn = (HttpURLConnection) uri.openConnection();
            // 允許輸入
            conn.setDoInput(true);
            // 允許輸出
            conn.setDoOutput(true);
            conn.setUseCaches(false);
            // Post方式
            conn.setRequestMethod("POST");
            // 設定request header 屬性
            conn.setRequestProperty("connection", "keep-alive");
            conn.setRequestProperty("Charsert", "UTF-8");
            conn.setRequestProperty("Content-Type", MULTIPART_FROM_DATA + ";boundary=" + BOUNDARY);
            // 組裝表單引數資料
            StringBuilder sb = new StringBuilder();
            for (Map.Entry<String, String> entry : params.entrySet()) {
                sb.append(PREFIX);
                sb.append(BOUNDARY);
                sb.append(LINEND);
                sb.append("Content-Disposition: form-data; name=\"" + entry.getKey() + "\"" + LINEND);
                sb.append("Content-Type: text/plain; charset=" + CHARSET + LINEND);
                sb.append("Content-Transfer-Encoding: 8bit" + LINEND);
                sb.append(LINEND);
                sb.append(entry.getValue());
                sb.append(LINEND);
            }
            // 獲取連線傳送引數資料
            outStream = new DataOutputStream(conn.getOutputStream());
            outStream.write(sb.toString().getBytes());
            // 傳送檔案資料
            if (files != null)
                for (Map.Entry<String, File> file : files.entrySet()) {
                    StringBuilder sb1 = new StringBuilder();
                    sb1.append(PREFIX);
                    sb1.append(BOUNDARY);
                    sb1.append(LINEND);
                    sb1.append("Content-Disposition: form-data; name=\"file\"; filename=\"" + file.getKey() + "\""
                            + LINEND);
                    sb1.append("Content-Type: application/octet-stream; charset=" + CHARSET + LINEND);
                    sb1.append(LINEND);
                    // 請求頭結束至少有一個空行（即有兩對\r\n）表示請求頭結束了
                    if (D)
                        Log.d("TAG", "request start:" + sb1.toString());
                    outStream.write(sb1.toString().getBytes());
                    InputStream is = new FileInputStream(file.getValue());
                    byte[] buffer = new byte[1024];
                    int len = 0;
                    while ((len = is.read(buffer)) != -1) {
                        outStream.write(buffer, 0, len);
                    }
                    is.close();
                    // 一個檔案結束一個空行
                    outStream.write(LINEND.getBytes());
                }
            // 請求結束的邊界列印
            byte[] end_data = (PREFIX + BOUNDARY + PREFIX + LINEND).getBytes();
            Log.d("TAG", "request end:" + new String(end_data).toString());
            outStream.write(end_data);
            outStream.flush();
            outStream.close();
            // 獲取響應碼
            int ret = conn.getResponseCode();
            retStr = String.valueOf(ret);
            if (ret == 200) {
                String result = StrUtil.convertStreamToString(conn.getInputStream());
                return result;
            }
        } catch (Exception e) {
            throw new AppException(e);
        } finally {
            if (conn != null) {
                conn.disconnect();
            }
        }
        return retStr;
    }

    /**
     * 獲取檔名，通過網路獲取，如果網路失敗擷取檔案地址URL作為檔名，獲取的是最後一個“/”以後的字串.
     * 
     * @param strUrl
     *            檔案地址
     * @return 檔名
     */
    public static String getFileNameFromUrl(String strUrl) {
        String name = null;
        try {
            if (StrUtil.isEmpty(strUrl) || strUrl.indexOf("/") == -1 || strUrl.length() < 2) {
                URL url = new URL(strUrl);
                HttpURLConnection mHttpURLConnection = (HttpURLConnection) url.openConnection();
                mHttpURLConnection.setConnectTimeout(5 * 1000);
                mHttpURLConnection.setRequestMethod("GET");
                mHttpURLConnection.setRequestProperty("Accept",
                        "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");
                mHttpURLConnection.setRequestProperty("Accept-Language", "zh-CN");
                mHttpURLConnection.setRequestProperty("Referer", strUrl);
                mHttpURLConnection.setRequestProperty("Charset", "UTF-8");
                mHttpURLConnection.setRequestProperty("User-Agent",
                        "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
                mHttpURLConnection.setRequestProperty("Connection", "Keep-Alive");
                mHttpURLConnection.connect();
                if (mHttpURLConnection.getResponseCode() == 200) {
                    for (int i = 0;; i++) {
                        String mine = mHttpURLConnection.getHeaderField(i);
                        if (mine == null) {
                            break;
                        }
                        if ("content-disposition".equals(mHttpURLConnection.getHeaderFieldKey(i).toLowerCase())) {
                            Matcher m = Pattern.compile(".*filename=(.*)").matcher(mine.toLowerCase());
                            if (m.find())
                                return m.group(1);
                        }
                    }
                    // 預設取一個檔名
                    return DateUtil.getCurrentDate(DateUtil.dateFormatYMDHMS) + ".tmp";
                }
                return null;
            } else {
                int index = strUrl.lastIndexOf("/");
                name = strUrl.substring(index + 1);
            }
        } catch (Exception e) {
        }
        return name;
    }

    /**
     * 描述：從sd卡中的檔案讀取到byte[].
     *
     * @param path
     *            sd卡中檔案路徑
     * @return byte[]
     */
    public static byte[] getByteArrayFromSD(String path) {
        byte[] bytes = null;
        ByteArrayOutputStream out = null;
        try {
            File file = new File(path);
            // SD卡是否存在
            if (!isCanUseSD()) {
                return null;
            }
            // 檔案是否存在
            if (!file.exists()) {
                return null;
            }

            long fileSize = file.length();
            if (fileSize > Integer.MAX_VALUE) {
                return null;
            }

            FileInputStream in = new FileInputStream(path);
            out = new ByteArrayOutputStream(1024);
            byte[] buffer = new byte[1024];
            int size = 0;
            while ((size = in.read(buffer)) != -1) {
                out.write(buffer, 0, size);
            }
            in.close();
            bytes = out.toByteArray();

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                try {
                    out.close();
                } catch (Exception e) {
                }
            }
        }
        return bytes;
    }

    /**
     * 描述：將byte陣列寫入檔案.
     *
     * @param path
     *            the path
     * @param content
     *            the content
     * @param create
     *            the create
     */
    public static void writeByteArrayToSD(String path, byte[] content, boolean create) {

        FileOutputStream fos = null;
        try {
            File file = new File(path);
            // SD卡是否存在
            if (!isCanUseSD()) {
                return;
            }
            // 檔案是否存在
            if (!file.exists()) {
                if (create) {
                    File parent = file.getParentFile();
                    if (!parent.exists()) {
                        parent.mkdirs();
                        file.createNewFile();
                    }
                } else {
                    return;
                }
            }
            fos = new FileOutputStream(path);
            fos.write(content);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (fos != null) {
                try {
                    fos.close();
                } catch (Exception e) {
                }
            }
        }
    }

    /**
     * 描述：SD卡是否能用.
     *
     * @return true 可用,false不可用
     */
    public static boolean isCanUseSD() {
        try {
            return Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    /**
     * 描述：獲取預設的圖片儲存全路徑.
     *
     * @return the default image down path dir
     */
    public static String getDefaultImageDownPathDir() {
        String pathDir = null;
        try {
            if (!isCanUseSD()) {
                return null;
            }
            // 初始化圖片儲存路徑
            File fileRoot = Environment.getExternalStorageDirectory();
            File dirFile = new File(fileRoot.getAbsolutePath() + FileUtil.downPathImageDir);
            if (!dirFile.exists()) {
                dirFile.mkdirs();
            }
            pathDir = dirFile.getPath();
        } catch (Exception e) {
        }
        return pathDir;
    }

}