Android 讀取手機資料夾向指定資料夾下存放
阿新 • • 發佈：2019-02-09
昨天專案需要向指定的資料夾下儲存圖片，需要使用檔案管理器去選擇指定的資料夾，當然最後由於邏輯太奇葩(不能選擇資料夾，只能選擇資料夾下的某一個檔案)被否定了，改為自己讀取手機儲存的資料夾，並且可以建立。當中遇到了幾個問題記錄一下：
1.手機儲存現在由三部分組成了基本上：內部儲存、手機內建外部儲存(ROM)、手機SD卡
1）內部儲存：
getFilesDir() 2）手機內建外部儲存(Rom)：
這個方法可以得到檔案new File(Environment.getExternalStorageDirectory().getAbsolutePath())
3）SD卡儲存 問題來了，上面的方法好像似曾相識，不就是得到Sd卡嗎？我也是被困擾了很久，當然也沒得到答案，沒辦法了，通過下面方法得到了：
File file = new File("/storage/sdcard1");
if (null != file.listFiles() && file.listFiles().length > 0) {
fileNameList.add("外接儲存");
}更正：如果用以上方法來判斷是否掛在sd卡，以及獲取sd卡的根目錄，測試中有些手機是不準確的，因為有的手機外接sd卡的根路徑不一定是“/storage/sdcard1”，因此找個一個大神的方法，抽取出來他的工具類以及bean類，如下：
public class StorageUtils { public static ArrayList<StorageBean> getStorageData(Context pContext) { final StorageManager storageManager = (StorageManager) pContext.getSystemService(Context.STORAGE_SERVICE); try { //得到StorageManager中的getVolumeList()方法的物件 final Method getVolumeList = storageManager.getClass().getMethod("getVolumeList"); //得到StorageVolume類的物件 final Class<?> storageValumeClazz = Class.forName("android.os.storage.StorageVolume"); //獲得StorageVolume中的一些方法 final Method getPath = storageValumeClazz.getMethod("getPath"); Method isRemovable = storageValumeClazz.getMethod("isRemovable"); Method mGetState = null; //getState 方法是在4.4_r1之後的版本加的，之前版本（含4.4_r1）沒有 // （http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/4.4_r1/android/os/Environment.java/） if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT) { try { mGetState = storageValumeClazz.getMethod("getState"); } catch (NoSuchMethodException e) { e.printStackTrace(); } } //呼叫getVolumeList方法，引數為：“誰”中呼叫這個方法 final Object invokeVolumeList = getVolumeList.invoke(storageManager); final int length = Array.getLength(invokeVolumeList); ArrayList<StorageBean> list = new ArrayList<>(); for (int i = 0; i < length; i++) { final Object storageValume = Array.get(invokeVolumeList, i);//得到StorageVolume物件 final String path = (String) getPath.invoke(storageValume); final boolean removable = (Boolean) isRemovable.invoke(storageValume); String state; if (mGetState != null) { state = (String) mGetState.invoke(storageValume); } else { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) { state = Environment.getStorageState(new File(path)); } else { if (removable) { state = EnvironmentCompat.getStorageState(new File(path)); } else { //不能移除的儲存介質，一直是mounted state = Environment.MEDIA_MOUNTED; } } } long totalSize = 0; long availaleSize = 0; if (Environment.MEDIA_MOUNTED.equals(state)) { totalSize = StorageUtils.getTotalSize(path); availaleSize = StorageUtils.getAvailableSize(path); } StorageBean storageBean = new StorageBean(); storageBean.setAvailableSize(availaleSize); storageBean.setTotalSize(totalSize); storageBean.setMounted(state); storageBean.setPath(path); storageBean.setRemovable(removable); list.add(storageBean); } return list; } catch (NoSuchMethodException e) { e.printStackTrace(); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } return null; } private static long getTotalSize(String path) { try { final StatFs statFs = new StatFs(path); long blockSize = 0; long blockCountLong = 0; if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) { blockSize = statFs.getBlockSizeLong(); blockCountLong = statFs.getBlockCountLong(); } else { blockSize = statFs.getBlockSize(); blockCountLong = statFs.getBlockCount(); } return blockSize * blockCountLong; } catch (Exception e) { e.printStackTrace(); return 0; } } private static long getAvailableSize(String path) { try { final StatFs statFs = new StatFs(path); long blockSize = 0; long availableBlocks = 0; if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) { blockSize = statFs.getBlockSizeLong(); availableBlocks = statFs.getAvailableBlocksLong(); } else { blockSize = statFs.getBlockSize(); availableBlocks = statFs.getAvailableBlocks(); } return availableBlocks * blockSize; } catch (Exception e) { e.printStackTrace(); return 0; } } private static final long A_GB = 1073741824; private static final long A_MB = 1048576; private static final int A_KB = 1024; public static String fmtSpace(long space) { if (space <= 0) { return "0"; } double gbValue = (double) space / A_GB; if (gbValue >= 1) { return String.format("%.2fGB", gbValue); } else { double mbValue = (double) space / A_MB; if (mbValue >= 1) { return String.format("%.2fMB", mbValue); } else { final double kbValue = space / A_KB; return String.format("%.2fKB", kbValue); } } } }
public class StorageBean implements Parcelable {
/**
* 根路徑
*/
private String path;
/**
*掛在情況 一種是掛在了 mounted 一種是未掛在 removed
*/
private String mounted;
/**
* 是否可以移除,如果不可移除表示內部儲存，可移除代表TF儲存(外掛SD卡)
*/
private boolean removable;
/**
* 總共大小
*/
private long totalSize;
/**
* 可用大小
*/
private long availableSize;
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public String getMounted() {
return mounted;
}
public void setMounted(String mounted) {
this.mounted = mounted;
}
public boolean getRemovable() {
return removable;
}
public void setRemovable(boolean removable) {
this.removable = removable;
}
public long getTotalSize() {
return totalSize;
}
public void setTotalSize(long totalSize) {
this.totalSize = totalSize;
}
public long getAvailableSize() {
return availableSize;
}
public void setAvailableSize(long availableSize) {
this.availableSize = availableSize;
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(this.path);
dest.writeString(this.mounted);
dest.writeByte(removable ? (byte) 1 : (byte) 0);
dest.writeLong(this.totalSize);
dest.writeLong(this.availableSize);
}
public StorageBean() {
}
protected StorageBean(Parcel in) {
this.path = in.readString();
this.mounted = in.readString();
this.removable = in.readByte() != 0;
this.totalSize = in.readLong();
this.availableSize = in.readLong();
}
public static final Parcelable.Creator<StorageBean> CREATOR = new Parcelable.Creator<StorageBean>() {
@Override
public StorageBean createFromParcel(Parcel source) {
return new StorageBean(source);
}
@Override
public StorageBean[] newArray(int size) {
return new StorageBean[size];
}
};
@Override
public String toString() {
return "StorageBean{" +
"path='" + path + '\'' +
", mounted='" + mounted + '\'' +
", removable=" + removable +
", totalSize=" + totalSize +
", availableSize=" + availableSize +
'}';
}
}2. Android6.0系統的手機讀取不到外接儲存下面的檔案和資料夾
File[] files = file.listFiles(); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {//6.0手機
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED ||
ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {//沒有授權許可權
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.READ_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_READ_CONTACTS_SD);
} else {//授權了許可權
file = new File("/storage/sdcard1");
nextFileList(file);
}
} else {//6.0以下系統
file = new File("/storage/sdcard1");
nextFileList(file);
} @Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {//手機內建外部存貯
// If request is cancelled, the result arrays are empty.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {//授權同意
file = new File(Environment.getExternalStorageDirectory().getAbsolutePath());
nextFileList(file);
} else {//授權被拒絕
}
}
break;
case MY_PERMISSIONS_REQUEST_READ_CONTACTS_SD://sd卡
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {//授權同意
file = new File("/storage/sdcard1");
nextFileList(file);
} else {//授權被拒絕
}
break;
}
}3.顯示的資料夾中含有隱藏的資料夾，需要刪除掉，這個其實很簡單，因為隱藏的資料夾都是以“.”開頭的，所以使用如下方法就可以，順便還有資料夾按照字母排序的方法
for (int num = 0; num < files.length; num++) {
if (files[num].isDirectory()) {
String name = files[num].getName();
if (!name.startsWith(".")) {//排除掉隱藏的資料夾
fileNameList.add(name);
}
}
}
Collections.sort(fileNameList, Collator.getInstance(Locale.ENGLISH));//對資料夾名稱排序最後把整個demo放到我們資源中，有需要的可以下載。。。。