开启文件上传，可使用HTML5标签 唤出系统文件管理器或自定义文件管理器，然后选择文件。
MainActivity.java:
private WebView webView;private WVChromeClient wv = null;@Overrideprotected void onCreate(Bundle savedInstanceState) {setContentView(R.layout.activity_main);webView = (WebView) findViewById(R.id.wv_webview);WebSettings settings = webView.getSettings();settings.setUseWideViewPort(true);settings.setJavaScriptEnabled(true);wv = new WVChromeClient(this,MainActivity.this);webView.setWebChromeClient(wv);} @Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == WVChromeClient.CHOOSER_REQUEST) { // 处理返回的文件wv.onActivityResultFileChooser(requestCode, resultCode, data); // 调用 WVChromeClient 类中的 回调方法}}WVChromeClient.java：
public class WVChromeClient extends WebChromeClient {private static final String TAG = "WebChromeClient：";public final static int CHOOSER_REQUEST = 0x33;private ValueCallback uploadFiles = null;Context context;MainActivity _m;public WVChromeClient(Context _context, MainActivity mainActivity){context = _context;_m = mainActivity;}// 第一种方式@Overridepublic boolean onShowFileChooser(WebView webView, ValueCallback filePathCallback, FileChooserParams fileChooserParams) {uploadFiles = filePathCallback;Intent i = fileChooserParams.createIntent();i.addCategory(Intent.CATEGORY_OPENABLE);i.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true); // 设置多选_m.startActivityForResult(Intent.createChooser(i, "Image Chooser"), CHOOSER_REQUEST);return true;}// 第二种方式（过滤文件格式）@Overridepublic boolean onShowFileChooser(WebView webView, ValueCallback filePathCallback, FileChooserParams fileChooserParams) {uploadFiles = filePathCallback;Intent i = new Intent(Intent.ACTION_GET_CONTENT);i.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);i.setType("*/*"); // 设置文件类型String[] mimeTypes = { "image/*,audio/*,video/*,*/*" };i.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes); // 设置多种类型i.addCategory(Intent.CATEGORY_OPENABLE);_m.startActivityForResult(Intent.createChooser(i, "Image Chooser"), CHOOSER_REQUEST);return true;}// 文件选择回调（在 MainActivity.java 的 onActivityResult中调用此方法）@TargetApi(Build.VERSION_CODES.LOLLIPOP)public void onActivityResultFileChooser(int requestCode, int resultCode, Intent intent) {if (requestCode != CHOOSER_REQUEST || uploadFiles == null)return;Uri[] results = null;if (resultCode == Activity.RESULT_OK) {if (intent != null) {String dataString = intent.getDataString();ClipData clipData = intent.getClipData();if (clipData != null) {results = new Uri[clipData.getItemCount()];for (int i = 0; i < clipData.getItemCount(); i++) {ClipData.Item item = clipData.getItemAt(i);results[i] = item.getUri();}}if (dataString != null)results = new Uri[]{Uri.parse(dataString)};}}uploadFiles.onReceiveValue(results);uploadFiles = null;}}2、唤出自定义文件管理器2.1 使用第三方插件这里使用 AndroidFilePicker 插件可自定义文件管理器，见详细使用
（1）添加依赖
在项目 build.gradle 配置文件添加仓库：
allprojects {repositories {...maven { url 'https://jitpack.io' }}}在子模块（app）的配置文件添加依赖：
dependencies {implementation 'me.rosuh:AndroidFilePicker:0.8.2'}此库需要一个权限：
android.permission.READ_EXTERNAL_STORAGE
如果您没有提前授予，这个库会自动申请该权限的。
修改上文 WVChromeClient 类中的 onShowFileChooser() 方法：
private ValueCallback uploadFiles = null;// 重写选择文件@Overridepublic boolean onShowFileChooser(WebView webView, ValueCallback filePathCallback,FileChooserParams fileChooserParams) {uploadFiles = filePathCallback;String uDiskUrl = getUDisk(); // 检测U盘if(uDiskUrl != null) {showSingleAlertDialog(uDiskUrl); // 弹出选择框} else {showFilePickerManager(""); // 直接打开本地路径，若无需支持U盘则可以直接调用此方法唤出自定义文件管理器}return true;}// 判断是否存在U盘private String getUDisk() {String path = "/mnt/usb/"; // u盘路径File storage = new File(path);File[] files = storage.listFiles();if(files != null && files.length != 0) {return path + files[0].getName() + "/";}return null;}// 打开文件管理器private void showFilePickerManager(String path) {FilePickerManager.from((Activity) context) // context 为上文实例化 WVChromeClient 类时传入.setCustomRootPath(path).forResult(CHOOSER_REQUEST);}private int checkedItem = 0;private boolean isNotOK = true;// 选择框private void showSingleAlertDialog(String path) {String[] items = {"本地存储", "U盘"};AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);alertBuilder.setTitle("请选择");alertBuilder.setSingleChoiceItems(items, 0, (dialogInterface, i) -> {checkedItem = i;});alertBuilder.setPositiveButton("确定", (dialogInterface, i) -> {isNotOK = false;dialogInterface.dismiss();String paths = "";if(checkedItem == 1) {paths = path; // 当前选择U盘，默认为本地存储}showFilePickerManager(paths);});alertBuilder.setNegativeButton("取消", (dialogInterface, i) -> dialogInterface.dismiss());alertBuilder.setOnDismissListener(dialog -> {if(isNotOK) { // 若没有选择确定按钮则取消文件上传uploadFiles.onReceiveValue(null);uploadFiles = null;}});alertBuilder.show();}// 文件选择回调@TargetApi(Build.VERSION_CODES.LOLLIPOP)public void onActivityResultFileChooser(int requestCode, int resultCode, Intent intent) {if (requestCode != Config.CHOOSER_REQUEST_CODE || uploadFiles == null)return;Uri[] results = null;if (resultCode == Activity.RESULT_OK) {List list = FilePickerManager.obtainData(); // 取到选择的文件列表results = new Uri[list.size()];for (int i = 0; i < list.size(); i++) {String item = list.get(i);Uri uri = getUriForFile(new File(item));results[i] = uri;}}uploadFiles.onReceiveValue(results);uploadFiles = null;isNotOK = true;}// File 转 Uriprivate Uri getUriForFile(File file) {String packageName = getPackage(context).packageName;Uri contentUri = FileProvider.getUriForFile(context,packageName+".fileProvider", file); // 需要 FileProvider，详细使用见下文return contentUri;}// 获取当前包名public static PackageInfo getPackage(Context context) {PackageManager manager = context.getPackageManager();try {PackageInfo info = manager.getPackageInfo(context.getPackageName(), 0);return info;} catch (PackageManager.NameNotFoundException e) {e.printStackTrace();return null;}}FileProvider 使用详见
2.2 手写文件管理页面手写文件管理页面有两个个步骤：获取文件列表、展示文件列表
（1）获取文件列表
按一般文件管理器大致有几个目录：文档、音频、视频、图片、下载、所有文件目录
public class FileManage {private Context _c;private static final String TAG = "FileManage：";public FileManage(Context context) {_c = context;}// 获取视频public JSONObject getVideos() { // 这里返回一个 JSONObject，返回格式可以自行定义Cursor c = null;JSONArray array = new JSONArray();try {Log.e(TAG,MediaStore.Video.Media.EXTERNAL_CONTENT_URI.toString());c = _c.getContentResolver().query(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, null, null, null, MediaStore.Video.Media.DEFAULT_SORT_ORDER);while (c.moveToNext()) {String path = c.getString(c.getColumnIndexOrThrow(MediaStore.Video.Media.DATA));// 路径if (!new File(path).exists()) {continue;}int id = c.getInt(c.getColumnIndexOrThrow(MediaStore.Video.Media._ID));// 视频的idString name = c.getString(c.getColumnIndexOrThrow(MediaStore.Video.Media.DISPLAY_NAME)); // 视频名称String resolution = c.getString(c.getColumnIndexOrThrow(MediaStore.Video.Media.RESOLUTION)); //分辨率long size = c.getLong(c.getColumnIndexOrThrow(MediaStore.Video.Media.SIZE));// 大小long duration = c.getLong(c.getColumnIndexOrThrow(MediaStore.Video.Media.DURATION));// 时长long date = c.getLong(c.getColumnIndexOrThrow(MediaStore.Video.Media.DATE_MODIFIED));//修改时间JSONObject obj = new JSONObject();obj.put("id",id);obj.put("name",name);obj.put("url",path);obj.put("resolution",resolution);obj.put("size",size);obj.put("duration",duration);obj.put("time",getDateToString(date*1000));obj.put("timestamp", date*1000);array.put(obj);}} catch (Exception e) {e.printStackTrace();} finally {if (c != null) {c.close();}}File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MOVIES);JSONObject obj = new JSONObject();try {obj.put("name","视频");obj.put("svg","#icon-file_video");obj.put("url", file.getPath());if(array != null && array.length() != 0) {obj.put("child", array);}} catch (JSONException e) {e.printStackTrace();}return obj;}// 获取音频public JSONObject getMusics() {Cursor c = null;JSONArray array = new JSONArray();try {c = _c.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, null, null, null,MediaStore.Audio.Media.DEFAULT_SORT_ORDER);while (c.moveToNext()) {String path = c.getString(c.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA));// 路径if (!new File(path).exists()) {continue;}int id = c.getInt(c.getColumnIndexOrThrow(MediaStore.Audio.Media._ID)); // 歌曲的idString name = c.getString(c.getColumnIndexOrThrow(MediaStore.Audio.Media.DISPLAY_NAME)); // 歌曲名String album = c.getString(c.getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM)); // 专辑String artist = c.getString(c.getColumnIndexOrThrow(MediaStore.Audio.Media.ARTIST)); // 作者long size = c.getLong(c.getColumnIndexOrThrow(MediaStore.Audio.Media.SIZE));// 大小int duration = c.getInt(c.getColumnIndexOrThrow(MediaStore.Audio.Media.DURATION));// 时长long date = c.getLong(c.getColumnIndexOrThrow(MediaStore.Audio.Media.DATE_MODIFIED));//修改时间int albumId = c.getInt(c.getColumnIndexOrThrow(MediaStore.Audio.Media.ALBUM_ID));JSONObject obj = new JSONObject();obj.put("id",id);obj.put("name",name);obj.put("url",path);obj.put("album",album);obj.put("artist",artist);obj.put("size",size);obj.put("duration",duration);obj.put("time",getDateToString(date*1000));obj.put("timestamp", date*1000);obj.put("albumId",albumId);array.put(obj);}} catch (Exception e) {e.printStackTrace();} finally {if (c != null) {c.close();}}File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC);JSONObject obj = new JSONObject();try {obj.put("name","音频");obj.put("svg","#icon-file_music");obj.put("url", file.getPath());if(array != null && array.length() != 0) {obj.put("child", array);}} catch (JSONException e) {e.printStackTrace();}return obj;}// 获取图片public JSONObject getImages() {// 扫描图片Cursor c = null;JSONArray array = new JSONArray();try {c = _c.getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, null,MediaStore.Images.Media.MIME_TYPE + "= ? or " + MediaStore.Images.Media.MIME_TYPE + "= ?",new String[]{"image/jpeg", "image/png"}, MediaStore.Images.Media.DATE_MODIFIED);while (c.moveToNext()) {String path = c.getString(c.getColumnIndexOrThrow(MediaStore.Images.Media.DATA));// 路径//@SuppressLint("Range") String path = c.getString(c.getColumnIndex(MediaStore.Images.Media.DATA));// 路径File parentFile = new File(path).getParentFile();if (parentFile == null)continue;int id = c.getInt(c.getColumnIndexOrThrow(MediaStore.Images.Media._ID)); // 图片的idString name = c.getString(c.getColumnIndexOrThrow(MediaStore.Images.Media.DISPLAY_NAME)); // 图片名long size = c.getLong(c.getColumnIndexOrThrow(MediaStore.Images.Media.SIZE));// 大小long date = c.getLong(c.getColumnIndexOrThrow(MediaStore.Images.Media.DATE_MODIFIED));//修改时间JSONObject obj = new JSONObject();obj.put("id",id);obj.put("name",name);obj.put("url",path);obj.put("size",size);obj.put("time",getDateToString(date*1000));obj.put("timestamp", date*1000);array.put(obj);}} catch (Exception e) {e.printStackTrace();} finally {if (c != null) {c.close();}}File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);JSONObject obj = new JSONObject();try {obj.put("name","图片");obj.put("svg","#icon-file_img");obj.put("url", file.getPath());if(array != null && array.length() != 0) {obj.put("child", array);}} catch (JSONException e) {e.printStackTrace();}return obj;}// 获取文档public JSONObject getDocuments() {File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS);JSONObject obj = getFileList(file);try {obj.put("name","文档");obj.put("svg","#icon-file1");obj.put("isFilter",true);} catch (JSONException e) {e.printStackTrace();}return obj;}// 获取下载public JSONObject getDownloads() {File file = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS);JSONObject obj = getFileList(file);try {obj.put("name","下载");obj.put("svg","#icon-file_download");obj.put("isFilter",true);} catch (JSONException e) {e.printStackTrace();}return obj;}// 获取根文件public JSONObject getRoots() {File file = Environment.getExternalStorageDirectory();return getFileList(file);}// 获取本地文件public JSONObject getLocalStore() {JSONObject obj = getRoots();try {obj.put("name","本地");JSONArray array = new JSONArray();array.put(getDocuments());array.put(getMusics());array.put(getVideos());array.put(getImages());array.put(getDownloads());obj.put("typeList", array);} catch (JSONException e) {e.printStackTrace();}return obj;}// 获取U盘文件public JSONObject getDiskFiles() {JSONObject obj = null;String path = "/mnt/usb/";File file = new File(path);File[] files = file.listFiles();if(files != null && files.length != 0) {obj = getFileList(file);try {obj.put("name","U盘");} catch (JSONException e) {e.printStackTrace();}}return obj;}// 获取目录文件下所有文件列表private JSONObject getFileList(File file) {JSONObject message = new JSONObject();try {if(file.exists()){message.put("name", file.getName());message.put("url", file.getPath());message.put("timestamp", file.lastModified());message.put("time", getDateToString(file.lastModified()));message.put("size", file.length());File[] list = file.listFiles();if(list != null && list.length != 0) {List fileList = Arrays.asList(list);Collections.sort(fileList, (Comparator) (o1, o2) -> {if (o1.isDirectory() && o2.isFile())return -1;if (o1.isFile() && o2.isDirectory())return 1;return o1.getName().compareTo(o2.getName());});JSONArray arr = new JSONArray();for(File item : list) {arr.put(getFileList(item));}message.put("child", arr);} else {if(file.isDirectory()) {message.put("child",new JSONArray());}}}} catch (JSONException e) {e.printStackTrace();}return message;}// File 转 Uripublic Uri getUriForFile(File file) {String packageName = GetDevice.getPackage(_c).packageName;Uri contentUri = FileProvider.getUriForFile(_c,packageName+".fileProvider", file);return contentUri;}private String getDateToString(long milSecond) {String pattern = "yyyy-MM-dd HH:mm:ss";Date date = new Date(milSecond);SimpleDateFormat format = new SimpleDateFormat(pattern);return format.format(date);}// 获取视频缩略图public Bitmap getVideoThumbnail(int id) {Bitmap bitmap = null;BitmapFactory.Options options = new BitmapFactory.Options();options.inDither = false;options.inPreferredConfig = Bitmap.Config.ARGB_8888;bitmap = MediaStore.Video.Thumbnails.getThumbnail(_c.getContentResolver(), id, MediaStore.Images.Thumbnails.MICRO_KIND, options);return bitmap;}}（2）展示文件列表
通过上面的 FileManage 里面的方法就可以获取到 Android 系统里面大部分文件列表了
展示可以使用 Android 的 Activity 布局展示，这里使用的是 H5 写的文件管理，实现逻辑一致（取到文件列表->展示->选择文件->得到文件URI）。
在 WChromeClient.java 中编写
private ValueCallback uploadFiles = null;// 重写选择文件@Overridepublic boolean onShowFileChooser(WebView webView, ValueCallback filePathCallback,FileChooserParams fileChooserParams) {uploadFiles = filePathCallback; // 取到 filePathCallback 回调之后不做处理return true;}// 文件选择回调（这个方法提供给js调用）public void resultFileChoose(String json) { // 参数是前端js选择了一项或多项的列表Uri[] results = null;try {JSONArray jsonArray = new JSONArray(json);results = new Uri[jsonArray.length()];for(int i=0; i {const json = JSON.parse(val);this.fileList.push(json); // 文件列表});// 获取设备U盘目录toAndroid({ methods: 'getDiskFiles' }, val => {if (val !== 'null') {const json = JSON.parse(val);this.fileList.push(json);}});// 调用安卓方法export default function toAndroid(infor, success, error) { try {const { methods, params } = infor;let data = null;params ? (data = window.jsWebView[methods](params)) : (data = window.jsWebView[methods]());success && success(data); } catch (e) {error && error(); }}