android通用文件操作

最经用到android的SCCard的文件操作，因此稍作了整理，将它写成一个简单的工具类。其中，可以判断SDCard的是否可用，可用存储空间，文件的创建以及写入数据。经过测试，可以正常使用。代码如下：

[java]
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import android.os.Environment;
import android.os.StatFs;
import android.util.Log;

public class FileUtil {
    private static int bufferd = 1024;

    private FileUtil() {
    }

    /*
     *  <uses-permission
     * android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"/>  <uses-permission
     * android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     */

    // =================get SDCard information===================
    public static boolean isSdcardAvailable() {
        String status = Environment.getExternalStorageState();
        if (status.equals(Environment.MEDIA_MOUNTED)) {
            return true;
        }
        return false;
    }

    public static long getSDAllSizeKB() {
        // get path of sdcard
        File path = Environment.getExternalStorageDirectory();
        StatFs sf = new StatFs(path.getPath());
        // get single block size(Byte)
        long blockSize = sf.getBlockSize();
        // 获取所有数据块数
        long allBlocks = sf.getBlockCount();
        // 返回SD卡大小
        return (allBlocks * blockSize) / 1024; // KB
    }

    /**
     * free size for normal application
     *
     * @return
     */
    public static long getSDAvalibleSizeKB() {
        File path = Environment.getExternalStorageDirectory();
        StatFs sf = new StatFs(path.getPath());
        long blockSize = sf.getBlockSize();
        long avaliableSize = sf.getAvailableBlocks();
        return (avaliableSize * blockSize) / 1024;// KB
    }

    // =====================File Operation==========================
    public static boolean isFileExist(String director) {
        File file = new File(Environment.getExternalStorageDirectory()
                + File.separator + director);
        return file.exists();
    }

    /**
     * create multiple director
     *
     * @param path
     * @return
     */
    public static boolean createFile(String director) {
        if (isFileExist(director)) {
            return true;
        } else {
            File file = new File(Environment.getExternalStorageDirectory()
                    + File.separator + director);
            if (!file.mkdirs()) {
                return false;
            }
            return true;
        }
    }

    public static File writeToSDCardFile(String directory, String fileName,
            String content, boolean isAppend) {
        return writeToSDCardFile(directory, fileName, content, "", isAppend);
    }

    /**
     *
     * @param director
     *            (you don't need to begin with
     *            Environment.getExternalStorageDirectory()+File.separator)
     * @param fileName
     * @param content
     * @param encoding
     *            (UTF-8...)
     * @param isAppend
     *            : Context.MODE_APPEND
     * @return
     */
    public static File writeToSDCardFile(String directory, String fileName,
            String content, String encoding, boolean isAppend) {
        // mobile SD card path +path
        File file = null;
        OutputStream os = null;
        try {
            if (!createFile(directory)) {
                return file;
            }
            file = new File(Environment.getExternalStorageDirectory()
                &nb

补充：移动开发 , Android ,