[Android Framework]獲取U盤 SD 狀態

Android 4.4 SD 和 U盤 的狀態

通過獲取StorageVolume 類來判斷 是sd還是U盤。我們來看一下這個類

package android.os.storage;

import android.content.Context;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.UserHandle;

import com.android.internal.util.IndentingPrintWriter;

import java.io.CharArrayWriter;
import java.io.File;

/**
 * Description of a storage volume and its capabilities, including the
 * filesystem path where it may be mounted.
 *
 * @hide
 */
public class StorageVolume implements Parcelable {

    // TODO: switch to more durable token
    private int mStorageId;

    private final File mPath;
    private final int mDescriptionId;
    private final boolean mPrimary;
    private final boolean mRemovable;
    private final boolean mEmulated;
    private final int mMtpReserveSpace;
    private final boolean mAllowMassStorage;
    /** Maximum file size for the storage, or zero for no limit */
    private final long mMaxFileSize;
    /** When set, indicates exclusive ownership of this volume */
    private final UserHandle mOwner;

    private String mUuid;
    private String mUserLabel;
    private String mState;

    // StorageVolume extra for ACTION_MEDIA_REMOVED, ACTION_MEDIA_UNMOUNTED, ACTION_MEDIA_CHECKING,
    // ACTION_MEDIA_NOFS, ACTION_MEDIA_MOUNTED, ACTION_MEDIA_SHARED, ACTION_MEDIA_UNSHARED,
    // ACTION_MEDIA_BAD_REMOVAL, ACTION_MEDIA_UNMOUNTABLE and ACTION_MEDIA_EJECT broadcasts.
    public static final String EXTRA_STORAGE_VOLUME = "storage_volume";

    // About storage volume format fs type
    public static final String EXTRA_FORMAT_FSTYPE = "format_fstype";   

    public StorageVolume(File path, int descriptionId, boolean primary, boolean removable,
            boolean emulated, int mtpReserveSpace, boolean allowMassStorage, long maxFileSize,
            UserHandle owner) {
        mPath = path;
        mDescriptionId = descriptionId;
        mPrimary = primary;
        mRemovable = removable;
        mEmulated = emulated;
        mMtpReserveSpace = mtpReserveSpace;
        mAllowMassStorage = allowMassStorage;
        mMaxFileSize = maxFileSize;
        mOwner = owner;
    }

    private StorageVolume(Parcel in) {
        mStorageId = in.readInt();
        mPath = new File(in.readString());
        mDescriptionId = in.readInt();
        mPrimary = in.readInt() != 0;
        mRemovable = in.readInt() != 0;
        mEmulated = in.readInt() != 0;
        mMtpReserveSpace = in.readInt();
        mAllowMassStorage = in.readInt() != 0;
        mMaxFileSize = in.readLong();
        mOwner = in.readParcelable(null);
        mUuid = in.readString();
        mUserLabel = in.readString();
        mState = in.readString();
    }

    public static StorageVolume fromTemplate(StorageVolume template, File path, UserHandle owner) {
        return new StorageVolume(path, template.mDescriptionId, template.mPrimary,
                template.mRemovable, template.mEmulated, template.mMtpReserveSpace,
                template.mAllowMassStorage, template.mMaxFileSize, owner);
    }

    /**
     * Returns the mount path for the volume.
     *
     * @return the mount path
     */
    public String getPath() {
        return mPath.toString();
    }

    public File getPathFile() {
        return mPath;
    }

    /**
     * Returns a user visible description of the volume.
     *
     * @return the volume description
     */
    public String getDescription(Context context) {
        return context.getResources().getString(mDescriptionId);
    }

    public int getDescriptionId() {
        return mDescriptionId;
    }

    public boolean isPrimary() {
        return mPrimary;
    }

    /**
     * Returns true if the volume is removable.
     *
     * @return is removable
     */
    public boolean isRemovable() {
        return mRemovable;
    }

    /**
     * Returns true if the volume is emulated.
     *
     * @return is removable
     */
    public boolean isEmulated() {
        return mEmulated;
    }

    /**
     * Returns the MTP storage ID for the volume.
     * this is also used for the storage_id column in the media provider.
     *
     * @return MTP storage ID
     */
    public int getStorageId() {
        return mStorageId;
    }

    /**
     * Do not call this unless you are MountService
     */
    public void setStorageId(int index) {
        // storage ID is 0x00010001 for primary storage,
        // then 0x00020001, 0x00030001, etc. for secondary storages
        mStorageId = ((index + 1) << 16) + 1;
    }

    /**
     * Number of megabytes of space to leave unallocated by MTP.
     * MTP will subtract this value from the free space it reports back
     * to the host via GetStorageInfo, and will not allow new files to
     * be added via MTP if there is less than this amount left free in the storage.
     * If MTP has dedicated storage this value should be zero, but if MTP is
     * sharing storage with the rest of the system, set this to a positive value
     * to ensure that MTP activity does not result in the storage being
     * too close to full.
     *
     * @return MTP reserve space
     */
    public int getMtpReserveSpace() {
        return mMtpReserveSpace;
    }

    /**
     * Returns true if this volume can be shared via USB mass storage.
     *
     * @return whether mass storage is allowed
     */
    public boolean allowMassStorage() {
        return mAllowMassStorage;
    }

    /**
     * Returns maximum file size for the volume, or zero if it is unbounded.
     *
     * @return maximum file size
     */
    public long getMaxFileSize() {
        return mMaxFileSize;
    }

    public UserHandle getOwner() {
        return mOwner;
    }

    public void setUuid(String uuid) {
        mUuid = uuid;
    }

    public String getUuid() {
        return mUuid;
    }

    /**
     * Parse and return volume UUID as FAT volume ID, or return -1 if unable to
     * parse or UUID is unknown.
     */
    public int getFatVolumeId() {
        if (mUuid == null || mUuid.length() != 9) {
            return -1;
        }
        try {
            return Integer.parseInt(mUuid.replace("-", ""), 16);
        } catch (NumberFormatException e) {
            return -1;
        }
    }

    public void setUserLabel(String userLabel) {
        mUserLabel = userLabel;
    }

    public String getUserLabel() {
        return mUserLabel;
    }

    public void setState(String state) {
        mState = state;
    }

    public String getState() {
        return mState;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof StorageVolume && mPath != null) {
            StorageVolume volume = (StorageVolume)obj;
            return (mPath.equals(volume.mPath));
        }
        return false;
    }

    @Override
    public int hashCode() {
        return mPath.hashCode();
    }

    @Override
    public String toString() {
        final CharArrayWriter writer = new CharArrayWriter();
        dump(new IndentingPrintWriter(writer, "    ", 80));
        return writer.toString();
    }

    public void dump(IndentingPrintWriter pw) {
        pw.println("StorageVolume:");
        pw.increaseIndent();
        pw.printPair("mStorageId", mStorageId);
        pw.printPair("mPath", mPath);
        pw.printPair("mDescriptionId", mDescriptionId);
        pw.printPair("mPrimary", mPrimary);
        pw.printPair("mRemovable", mRemovable);
        pw.printPair("mEmulated", mEmulated);
        pw.printPair("mMtpReserveSpace", mMtpReserveSpace);
        pw.printPair("mAllowMassStorage", mAllowMassStorage);
        pw.printPair("mMaxFileSize", mMaxFileSize);
        pw.printPair("mOwner", mOwner);
        pw.printPair("mUuid", mUuid);
        pw.printPair("mUserLabel", mUserLabel);
        pw.printPair("mState", mState);
        pw.decreaseIndent();
    }

    public static final Creator<StorageVolume> CREATOR = new Creator<StorageVolume>() {
        @Override
        public StorageVolume createFromParcel(Parcel in) {
            return new StorageVolume(in);
        }

        @Override
        public StorageVolume[] newArray(int size) {
            return new StorageVolume[size];
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int flags) {
        parcel.writeInt(mStorageId);
        parcel.writeString(mPath.toString());
        parcel.writeInt(mDescriptionId);
        parcel.writeInt(mPrimary ? 1 : 0);
        parcel.writeInt(mRemovable ? 1 : 0);
        parcel.writeInt(mEmulated ? 1 : 0);
        parcel.writeInt(mMtpReserveSpace);
        parcel.writeInt(mAllowMassStorage ? 1 : 0);
        parcel.writeLong(mMaxFileSize);
        parcel.writeParcelable(mOwner, flags);
        parcel.writeString(mUuid);
        parcel.writeString(mUserLabel);
        parcel.writeString(mState);
    }
}

這個類用來描述儲存狀態，有幾個重要的引數：

• File mPath 路徑
• mRemovable 是否可移除，（U盤，SD）返回 true
• getDescription(context) 獲取裝置的描述 "sd" 就是SD卡，“USB”就是usb裝置

獲取儲存裝置

    mStorageManager = StorageManager.from(this);
    final StorageVolume[] storageVolumes = mStorageManager.getVolumeList();
    for (StorageVolume mVolume : storageVolumes) {
         if(mVolume != null){
            String description = mVolume.getDescription(context);
            Log.d(getClass().getName(), "description is: " + description);
            if(description != null && (description.contains("SD") || description.contains("sd"))){
               //這是sd
            }
            else if(description != null && (description.contains("USB") || description.contains("usb")
                    || description.contains("Usb"))){
                //這是usb
            }
        }
        }
    }

儲存裝置狀態和路徑

import android.os.storage.StorageManager;
import android.os.storage.StorageEventListener;
private StorageManager mStorageManager; 


 mStorageManager = StorageManager.from(this);
 

//註冊和反註冊

mStorageManager.registerListener(mStorageListener);


if (mStorageManager != null && mStorageListener != null) {
    mStorageManager.unregisterListener(mStorageListener);
}


    /**
     *
     * 監聽  path  路徑    oldState 上一個狀態      newState 當前狀態
     *  所有狀態 mounted   unmounted     removed     checking
     */
    StorageEventListener mStorageListener = new StorageEventListener() {
        @Override
        public void onStorageStateChanged(String path, String oldState, String newState) {
            Log.i("qkmin -voolesettings"," StorageEventListener Received storage state changed notification that " + path +
                    " changed state from " + oldState + " to " + newState);
            
  
        }
    };