File Upload in WebView

2018-12-31 03:24发布

I have been struggling to upload files from WebView since last few days and there is no progress. I googled and implemented all suggested solutions but none works, like: solutions suggested here, and so on.

Problem: I have a HTML page with the following code to upload a file. It works fine in a desktop browser like Firefox and built-in browser of emulator / AVD i.e., when I click "Browse..." button rendered by element, browser opens a Dialog box where I can choose a file to upload.

However, in the android 3.0 emulator / AVD, when I click on "Choose file", nothing happens, no file dialog is opened!!!

<form method="POST" enctype="multipart/form-data">
File to upload: <input type="file" name="uploadfile">&nbsp;&nbsp;
<input type="submit" value="Press to Upload..."> to upload the file!
</form>

Could anyone please suggest a possible solution at the earliest.

17条回答
临风纵饮
2楼-- · 2018-12-31 03:53

I found it necessary to define public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture), in Android 4.1. Then I followed Michel Olivier's solution.

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初与友歌
3楼-- · 2018-12-31 03:55

I found that I needed 3 interface definitions in order to handle various version of android.

public void openFileChooser(ValueCallback < Uri > uploadMsg) {
  mUploadMessage = uploadMsg;
  Intent i = new Intent(Intent.ACTION_GET_CONTENT);
  i.addCategory(Intent.CATEGORY_OPENABLE);
  i.setType("image/*");
  FreeHealthTrack.this.startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILECHOOSER_RESULTCODE);
}

public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType) {
  openFileChooser(uploadMsg);
}

public void openFileChooser(ValueCallback < Uri > uploadMsg, String acceptType, String capture) {
  openFileChooser(uploadMsg);
}
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无色无味的生活
4楼-- · 2018-12-31 03:56

hifarrer's full solution is very helpful to me.

but, I met many other problems - supporting other mime type, listing capture devices(camera, video, audio recoder), opening capture device immediately(ex: <input accept="image/*;capture"> )...

So, I made a solution that works exactly same as default web browser app.

I used android-4.4.3_r1/src/com/android/browser/UploadHandler.java. (thanks to Rupert Rawnsley )

package org.mospi.agatenativewebview;

import java.io.File;
import java.lang.reflect.Method;
import java.net.URL;

import android.app.Activity;
import android.app.AlertDialog;
import android.content.ActivityNotFoundException;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.view.View;
import android.webkit.JsResult;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebSettings.PluginState;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        WebView webView = (WebView) findViewById(R.id.webView1);

        initWebView(webView);
        webView.loadUrl("http://google.com"); // TODO input your url

    }

    private final static Object methodInvoke(Object obj, String method, Class<?>[] parameterTypes, Object[] args) {
        try {
            Method m = obj.getClass().getMethod(method, new Class[] { boolean.class });
            m.invoke(obj, args);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    private void initWebView(WebView webView) {

        WebSettings settings = webView.getSettings();

        settings.setJavaScriptEnabled(true);
        settings.setAllowFileAccess(true);
        settings.setDomStorageEnabled(true);
        settings.setCacheMode(WebSettings.LOAD_NO_CACHE);
        settings.setLoadWithOverviewMode(true);
        settings.setUseWideViewPort(true);
        settings.setSupportZoom(true);
        // settings.setPluginsEnabled(true);
        methodInvoke(settings, "setPluginsEnabled", new Class[] { boolean.class }, new Object[] { true });
        // settings.setPluginState(PluginState.ON);
        methodInvoke(settings, "setPluginState", new Class[] { PluginState.class }, new Object[] { PluginState.ON });
        // settings.setPluginsEnabled(true);
        methodInvoke(settings, "setPluginsEnabled", new Class[] { boolean.class }, new Object[] { true });
        // settings.setAllowUniversalAccessFromFileURLs(true);
        methodInvoke(settings, "setAllowUniversalAccessFromFileURLs", new Class[] { boolean.class }, new Object[] { true });
        // settings.setAllowFileAccessFromFileURLs(true);
        methodInvoke(settings, "setAllowFileAccessFromFileURLs", new Class[] { boolean.class }, new Object[] { true });

        webView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);
        webView.clearHistory();
        webView.clearFormData();
        webView.clearCache(true);

        webView.setWebChromeClient(new MyWebChromeClient());
        // webView.setDownloadListener(downloadListener);
    }

    UploadHandler mUploadHandler;

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) {

        if (requestCode == Controller.FILE_SELECTED) {
            // Chose a file from the file picker.
            if (mUploadHandler != null) {
                mUploadHandler.onResult(resultCode, intent);
            }
        }

        super.onActivityResult(requestCode, resultCode, intent);
    }

    class MyWebChromeClient extends WebChromeClient {
        public MyWebChromeClient() {

        }

        private String getTitleFromUrl(String url) {
            String title = url;
            try {
                URL urlObj = new URL(url);
                String host = urlObj.getHost();
                if (host != null && !host.isEmpty()) {
                    return urlObj.getProtocol() + "://" + host;
                }
                if (url.startsWith("file:")) {
                    String fileName = urlObj.getFile();
                    if (fileName != null && !fileName.isEmpty()) {
                        return fileName;
                    }
                }
            } catch (Exception e) {
                // ignore
            }

            return title;
        }

        @Override
        public boolean onJsAlert(WebView view, String url, String message, final JsResult result) {
            String newTitle = getTitleFromUrl(url);

            new AlertDialog.Builder(MainActivity.this).setTitle(newTitle).setMessage(message).setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    result.confirm();
                }
            }).setCancelable(false).create().show();
            return true;
            // return super.onJsAlert(view, url, message, result);
        }

        @Override
        public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) {

            String newTitle = getTitleFromUrl(url);

            new AlertDialog.Builder(MainActivity.this).setTitle(newTitle).setMessage(message).setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {
                    result.confirm();
                }
            }).setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    result.cancel();
                }
            }).setCancelable(false).create().show();
            return true;

            // return super.onJsConfirm(view, url, message, result);
        }

        // Android 2.x
        public void openFileChooser(ValueCallback<Uri> uploadMsg) {
            openFileChooser(uploadMsg, "");
        }

        // Android 3.0
        public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
            openFileChooser(uploadMsg, "", "filesystem");
        }

        // Android 4.1
        public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
            mUploadHandler = new UploadHandler(new Controller());
            mUploadHandler.openFileChooser(uploadMsg, acceptType, capture);
        }

        // Android 4.4, 4.4.1, 4.4.2
        // openFileChooser function is not called on Android 4.4, 4.4.1, 4.4.2,
        // you may use your own java script interface or other hybrid framework.          

        // Android 5.0.1
        public boolean onShowFileChooser(
                WebView webView, ValueCallback<Uri[]> filePathCallback,
                FileChooserParams fileChooserParams) {

            String acceptTypes[] = fileChooserParams.getAcceptTypes();

            String acceptType = "";
            for (int i = 0; i < acceptTypes.length; ++ i) {
                if (acceptTypes[i] != null && acceptTypes[i].length() != 0)
                    acceptType += acceptTypes[i] + ";";
            }
            if (acceptType.length() == 0)
                acceptType = "*/*";

            final ValueCallback<Uri[]> finalFilePathCallback = filePathCallback;

            ValueCallback<Uri> vc = new ValueCallback<Uri>() {

                @Override
                public void onReceiveValue(Uri value) {

                    Uri[] result;
                    if (value != null)
                        result = new Uri[]{value};
                    else
                        result = null;

                    finalFilePathCallback.onReceiveValue(result);

                }
            };

            openFileChooser(vc, acceptType, "filesystem");


            return true;
       }
    };

    class Controller {
        final static int FILE_SELECTED = 4;

        Activity getActivity() {
            return MainActivity.this;
        }
    }

    // copied from android-4.4.3_r1/src/com/android/browser/UploadHandler.java
    //////////////////////////////////////////////////////////////////////

    /*
     * Copyright (C) 2010 The Android Open Source Project
     *
     * Licensed under the Apache License, Version 2.0 (the "License");
     * you may not use this file except in compliance with the License.
     * You may obtain a copy of the License at
     *
     *      http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed under the License is distributed on an "AS IS" BASIS,
     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */

    // package com.android.browser;
    //
    // import android.app.Activity;
    // import android.content.ActivityNotFoundException;
    // import android.content.Intent;
    // import android.net.Uri;
    // import android.os.Environment;
    // import android.provider.MediaStore;
    // import android.webkit.ValueCallback;
    // import android.widget.Toast;
    //
    // import java.io.File;
    // import java.util.Vector;
    //
    // /**
    // * Handle the file upload callbacks from WebView here
    // */
    // public class UploadHandler {

    class UploadHandler {
        /*
         * The Object used to inform the WebView of the file to upload.
         */
        private ValueCallback<Uri> mUploadMessage;
        private String mCameraFilePath;
        private boolean mHandled;
        private boolean mCaughtActivityNotFoundException;
        private Controller mController;
        public UploadHandler(Controller controller) {
            mController = controller;
        }
        String getFilePath() {
            return mCameraFilePath;
        }
        boolean handled() {
            return mHandled;
        }
        void onResult(int resultCode, Intent intent) {
            if (resultCode == Activity.RESULT_CANCELED && mCaughtActivityNotFoundException) {
                // Couldn't resolve an activity, we are going to try again so skip
                // this result.
                mCaughtActivityNotFoundException = false;
                return;
            }
            Uri result = intent == null || resultCode != Activity.RESULT_OK ? null
                    : intent.getData();
            // As we ask the camera to save the result of the user taking
            // a picture, the camera application does not return anything other
            // than RESULT_OK. So we need to check whether the file we expected
            // was written to disk in the in the case that we
            // did not get an intent returned but did get a RESULT_OK. If it was,
            // we assume that this result has came back from the camera.
            if (result == null && intent == null && resultCode == Activity.RESULT_OK) {
                File cameraFile = new File(mCameraFilePath);
                if (cameraFile.exists()) {
                    result = Uri.fromFile(cameraFile);
                    // Broadcast to the media scanner that we have a new photo
                    // so it will be added into the gallery for the user.
                    mController.getActivity().sendBroadcast(
                            new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, result));
                }
            }
            mUploadMessage.onReceiveValue(result);
            mHandled = true;
            mCaughtActivityNotFoundException = false;
        }
        void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
            final String imageMimeType = "image/*";
            final String videoMimeType = "video/*";
            final String audioMimeType = "audio/*";
            final String mediaSourceKey = "capture";
            final String mediaSourceValueCamera = "camera";
            final String mediaSourceValueFileSystem = "filesystem";
            final String mediaSourceValueCamcorder = "camcorder";
            final String mediaSourceValueMicrophone = "microphone";
            // According to the spec, media source can be 'filesystem' or 'camera' or 'camcorder'
            // or 'microphone' and the default value should be 'filesystem'.
            String mediaSource = mediaSourceValueFileSystem;
            if (mUploadMessage != null) {
                // Already a file picker operation in progress.
                return;
            }
            mUploadMessage = uploadMsg;
            // Parse the accept type.
            String params[] = acceptType.split(";");
            String mimeType = params[0];
            if (capture.length() > 0) {
                mediaSource = capture;
            }
            if (capture.equals(mediaSourceValueFileSystem)) {
                // To maintain backwards compatibility with the previous implementation
                // of the media capture API, if the value of the 'capture' attribute is
                // "filesystem", we should examine the accept-type for a MIME type that
                // may specify a different capture value.
                for (String p : params) {
                    String[] keyValue = p.split("=");
                    if (keyValue.length == 2) {
                        // Process key=value parameters.
                        if (mediaSourceKey.equals(keyValue[0])) {
                            mediaSource = keyValue[1];
                        }
                    }
                }
            }
            //Ensure it is not still set from a previous upload.
            mCameraFilePath = null;
            if (mimeType.equals(imageMimeType)) {
                if (mediaSource.equals(mediaSourceValueCamera)) {
                    // Specified 'image/*' and requested the camera, so go ahead and launch the
                    // camera directly.
                    startActivity(createCameraIntent());
                    return;
                } else {
                    // Specified just 'image/*', capture=filesystem, or an invalid capture parameter.
                    // In all these cases we show a traditional picker filetered on accept type
                    // so launch an intent for both the Camera and image/* OPENABLE.
                    Intent chooser = createChooserIntent(createCameraIntent());
                    chooser.putExtra(Intent.EXTRA_INTENT, createOpenableIntent(imageMimeType));
                    startActivity(chooser);
                    return;
                }
            } else if (mimeType.equals(videoMimeType)) {
                if (mediaSource.equals(mediaSourceValueCamcorder)) {
                    // Specified 'video/*' and requested the camcorder, so go ahead and launch the
                    // camcorder directly.
                    startActivity(createCamcorderIntent());
                    return;
               } else {
                    // Specified just 'video/*', capture=filesystem or an invalid capture parameter.
                    // In all these cases we show an intent for the traditional file picker, filtered
                    // on accept type so launch an intent for both camcorder and video/* OPENABLE.
                    Intent chooser = createChooserIntent(createCamcorderIntent());
                    chooser.putExtra(Intent.EXTRA_INTENT, createOpenableIntent(videoMimeType));
                    startActivity(chooser);
                    return;
                }
            } else if (mimeType.equals(audioMimeType)) {
                if (mediaSource.equals(mediaSourceValueMicrophone)) {
                    // Specified 'audio/*' and requested microphone, so go ahead and launch the sound
                    // recorder.
                    startActivity(createSoundRecorderIntent());
                    return;
                } else {
                    // Specified just 'audio/*',  capture=filesystem of an invalid capture parameter.
                    // In all these cases so go ahead and launch an intent for both the sound
                    // recorder and audio/* OPENABLE.
                    Intent chooser = createChooserIntent(createSoundRecorderIntent());
                    chooser.putExtra(Intent.EXTRA_INTENT, createOpenableIntent(audioMimeType));
                    startActivity(chooser);
                    return;
                }
            }
            // No special handling based on the accept type was necessary, so trigger the default
            // file upload chooser.
            startActivity(createDefaultOpenableIntent());
        }
        private void startActivity(Intent intent) {
            try {
                mController.getActivity().startActivityForResult(intent, Controller.FILE_SELECTED);
            } catch (ActivityNotFoundException e) {
                // No installed app was able to handle the intent that
                // we sent, so fallback to the default file upload control.
                try {
                    mCaughtActivityNotFoundException = true;
                    mController.getActivity().startActivityForResult(createDefaultOpenableIntent(),
                            Controller.FILE_SELECTED);
                } catch (ActivityNotFoundException e2) {
                    // Nothing can return us a file, so file upload is effectively disabled.
                    Toast.makeText(mController.getActivity(), R.string.uploads_disabled,
                            Toast.LENGTH_LONG).show();
                }
            }
        }
        private Intent createDefaultOpenableIntent() {
            // Create and return a chooser with the default OPENABLE
            // actions including the camera, camcorder and sound
            // recorder where available.
            Intent i = new Intent(Intent.ACTION_GET_CONTENT);
            i.addCategory(Intent.CATEGORY_OPENABLE);
            i.setType("*/*");
            Intent chooser = createChooserIntent(createCameraIntent(), createCamcorderIntent(),
                    createSoundRecorderIntent());
            chooser.putExtra(Intent.EXTRA_INTENT, i);
            return chooser;
        }
        private Intent createChooserIntent(Intent... intents) {
            Intent chooser = new Intent(Intent.ACTION_CHOOSER);
            chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, intents);
            chooser.putExtra(Intent.EXTRA_TITLE,
                    mController.getActivity().getResources()
                            .getString(R.string.choose_upload));
            return chooser;
        }
        private Intent createOpenableIntent(String type) {
            Intent i = new Intent(Intent.ACTION_GET_CONTENT);
            i.addCategory(Intent.CATEGORY_OPENABLE);
            i.setType(type);
            return i;
        }
        private Intent createCameraIntent() {
            Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            File externalDataDir = Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_DCIM);
            File cameraDataDir = new File(externalDataDir.getAbsolutePath() +
                    File.separator + "browser-photos");
            cameraDataDir.mkdirs();
            mCameraFilePath = cameraDataDir.getAbsolutePath() + File.separator +
                    System.currentTimeMillis() + ".jpg";
            cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(mCameraFilePath)));
            return cameraIntent;
        }
        private Intent createCamcorderIntent() {
            return new Intent(MediaStore.ACTION_VIDEO_CAPTURE);
        }
        private Intent createSoundRecorderIntent() {
            return new Intent(MediaStore.Audio.Media.RECORD_SOUND_ACTION);
        }
    }
}

additional string resoruce of res/values/string.xml :

<string name="uploads_disabled">File uploads are disabled.</string>
<string name="choose_upload">Choose file for upload</string>

If you are using proguard, you may need below option in proguard-project.txt :

-keepclassmembers class * extends android.webkit.WebChromeClient {
   public void openFileChooser(...);
}

UPDATE #1 (2015.09.09)

adds code for Android 5.0.1 compatability.

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旧人旧事旧时光
5楼-- · 2018-12-31 03:57

I'm new to Andriod and struggled with this also. According to Google Reference Guide WebView.

By default, a WebView provides no browser-like widgets, does not enable JavaScript and web page errors are ignored. If your goal is only to display some HTML as a part of your UI, this is probably fine; the user won't need to interact with the web page beyond reading it, and the web page won't need to interact with the user. If you actually want a full-blown web browser, then you probably want to invoke the Browser application with a URL Intent rather than show it with a WebView.

Example code I executed in MainActvity.java.

 Uri uri = Uri.parse("https://www.example.com");
 Intent intent = new Intent(Intent.ACTION_VIEW, uri);
 startActivity(intent);

Excuted

package example.com.myapp;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.content.Intent;
import android.net.Uri;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Uri uri = Uri.parse("http://www.example.com/");
        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
        startActivity(intent);
        getSupportActionBar().hide();
    }}
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千与千寻千般痛.
7楼-- · 2018-12-31 04:07

Google's own browser offers such a comprehensive solution to this problem that it warrants it's own class:

openFileChooser implementation in Android 4.0.4

UploadHandler class in Android 4.0.4

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