Android 图片在SD卡及包下的存储

public class FileBitmap {
/**
* 获取sd卡中的bitmap,bitmap可见
*
* @param bitmap
*            读取bitmap的路径
* @return bitmap
*/
public static Bitmap getBitmapByPath(String fileNameString, String bitmapURL) {
String bitmapName = bitmapURL.substring(bitmapURL.lastIndexOf("/") + 1);
fileNameString = fileNameString + "/" + bitmapName;
BitmapFactory.Options options = new BitmapFactory.Options();
Bitmap bm = BitmapFactory.decodeFile(Environment.getExternalStorageDirectory()+fileNameString, options);
return bm;
}

/**
* 在SD卡中存储bitmap,bitmap可见
*
* @param fileName
*            保存bitmap的文件夹路径
* @param bitName
*            bitmap的路径
* @param mBitmap
*            要保存的bitmap
* @throws IOException
*/
public static void saveMyBitmap(String fileName, String bitmapURL,
Bitmap mBitmap) throws IOException {
String bitmapName = bitmapURL.substring(bitmapURL.lastIndexOf("/") + 1); // 传入一个远程图片的url，然后取最后的图片名字
File tmp = new File(Environment.getExternalStorageDirectory()+fileName);

if (!tmp.exists()) {
tmp.mkdir();
}
File f = new File(Environment.getExternalStorageDirectory()+fileName+"/"+bitmapURL);
f.createNewFile();
FileOutputStream fOut = null;
try {
fOut = new FileOutputStream(f);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
mBitmap.compress(Bitmap.CompressFormat.PNG, 100, fOut);

try {
fOut.flush();
fOut.close();
} catch (IOException e) {
e.printStackTrace();
}
}

/*
* 保存图片到本地,这个是把图片压缩成字节流然后保存到本地，所以本地的图片是无法显示的
*
* @param mBitmap
*
* @param imageURL
*
* @param cxt
*/
public static void saveBitmap(Bitmap mBitmap, String imageURL, Context cxt) {

String bitmapName = imageURL.substring(imageURL.lastIndexOf("/") + 1); // 传入一个远程图片的url，然后取最后的图片名字

ByteArrayOutputStream stream = new ByteArrayOutputStream();
mBitmap.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();

FileOutputStream fos = null;
ObjectOutputStream oos = null;

try {
fos = cxt.openFileOutput(bitmapName, Context.MODE_PRIVATE);
oos = new ObjectOutputStream(fos);
oos.writeObject(byteArray);
} catch (Exception e) {
e.printStackTrace();
// 这里是保存文件产生异常
} finally {
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
// fos流关闭异常
e.printStackTrace();
}
}
if (oos != null) {
try {
oos.close();
} catch (IOException e) {
// oos流关闭异常
e.printStackTrace();
}
}
}
}

/**
* 读取本地私有文件夹的图片
*
* @param name
* @param cxt
* @return
*/
public static Bitmap getBitmap(String fileName, Context cxt) {
String bitmapName = fileName.substring(fileName.lastIndexOf("/") + 1);
FileInputStream fis = null;
ObjectInputStream ois = null;
try {
fis = cxt.openFileInput(bitmapName);
ois = new ObjectInputStream(fis);
byte[] byteArray = (byte[]) ois.readObject();
Bitmap bitmap = BitmapFactory.decodeByteArray(byteArray, 0,
byteArray.length);
return bitmap;
} catch (Exception e) {
e.printStackTrace();
// 这里是读取文件产生异常
} finally {
if (fis != null) {
try {
fis.close();
} catch (IOException e) {
// fis流关闭异常
e.printStackTrace();
}
}
if (ois != null) {
try {
ois.close();
} catch (IOException e) {
// ois流关闭异常
e.printStackTrace();
}
}
}
// 读取产生异常，返回null
return null;
}

}