如何在android中从手机内部存储(Nexus 5)中获取所有视频文件

Question

我想从设备的内部内存中获取所有视频文件。

我尝试了以下方法，但没有得到结果

1. File file[] = Environment.getExternalStorageDirectory().listFiles();
2. File file= Environment.getDataDirectory();
3. File file[] = Environment.getRootDirectory().listFiles();
4. File file = Environment.getExternalStoragePublicDirectory();

Answer 1

我得到了这个的解决方案。。请查看以下代码

import android.os.Environment;
import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
public class ExternalStorage { 
    public static final String SD_CARD = "sdCard";
    public static final String EXTERNAL_SD_CARD = "externalSdCard";
    /** 
     * @return True if the external storage is available. False otherwise. 
     */ 
    public static boolean isAvailable() { 
        String state = Environment.getExternalStorageState();
        if (Environment.MEDIA_MOUNTED.equals(state) || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
            return true; 
        } 
        return false; 
    } 
    public static String getSdCardPath() {
        return Environment.getExternalStorageDirectory().getPath() + "/";
    } 
    /** 
     * @return True if the external storage is writable. False otherwise. 
     */ 
    public static boolean isWritable() { 
        String state = Environment.getExternalStorageState();
        if (Environment.MEDIA_MOUNTED.equals(state)) {
            return true; 
        } 
        return false; 
    } 
    /** 
     * @return A map of all storage locations available 
     */ 
    public static Map<String, File> getAllStorageLocations() {
        Map<String, File> map = new HashMap<String, File>(10);
        List<String> mMounts = new ArrayList<String>(10);
        List<String> mVold = new ArrayList<String>(10);
        mMounts.add("/mnt/sdcard");
        mVold.add("/mnt/sdcard");
        try { 
            File mountFile = new File("/proc/mounts");
            if(mountFile.exists()){
                Scanner scanner = new Scanner(mountFile);
                while (scanner.hasNext()) {
                    String line = scanner.nextLine();
                    if (line.startsWith("/dev/block/vold/")) {
                        String[] lineElements = line.split(" ");
                        String element = lineElements[1];
                        // don't add the default mount path 
                        // it's already in the list. 
                        if (!element.equals("/mnt/sdcard"))
                            mMounts.add(element);
                    } 
                } 
            } 
        } catch (Exception e) {
            e.printStackTrace();
        } 
        try { 
            File voldFile = new File("/system/etc/vold.fstab");
            if(voldFile.exists()){
                Scanner scanner = new Scanner(voldFile);
                while (scanner.hasNext()) {
                    String line = scanner.nextLine();
                    if (line.startsWith("dev_mount")) {
                        String[] lineElements = line.split(" ");
                        String element = lineElements[2];
                        if (element.contains(":"))
                            element = element.substring(0, element.indexOf(":"));
                        if (!element.equals("/mnt/sdcard"))
                            mVold.add(element);
                    } 
                } 
            } 
        } catch (Exception e) {
            e.printStackTrace();
        } 

        for (int i = 0; i < mMounts.size(); i++) {
            String mount = mMounts.get(i);
            if (!mVold.contains(mount))
                mMounts.remove(i--);
        } 
        mVold.clear();
        List<String> mountHash = new ArrayList<String>(10);
        for(String mount : mMounts){
            File root = new File(mount);
            if (root.exists() && root.isDirectory() && root.canWrite()) {
                File[] list = root.listFiles();
                String hash = "[";
                if(list!=null){
                    for(File f : list){
                        hash += f.getName().hashCode()+":"+f.length()+", ";
                    } 
                } 
                hash += "]";
                if(!mountHash.contains(hash)){
                    String key = SD_CARD + "_" + map.size();
                    if (map.size() == 0) {
                        key = SD_CARD;
                    } else if (map.size() == 1) {
                        key = EXTERNAL_SD_CARD;
                    } 
                    mountHash.add(hash);
                    map.put(key, root);
                } 
            } 
        } 
        mMounts.clear();
        if(map.isEmpty()){
                 map.put(SD_CARD, Environment.getExternalStorageDirectory());
        } 
        return map;
    } 
}