// Copyright 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
package org.chromium.android_webview;
import android.content.Context;
import android.content.res.AssetManager;
import android.net.Uri;
import android.util.Log;
import android.util.TypedValue;
import org.chromium.base.CalledByNative;
import org.chromium.base.JNINamespace;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLConnection;
import java.util.List;
/**
* Implements the Java side of Android URL protocol jobs.
* See android_protocol_handler.cc.
*/
@JNINamespace("android_webview")
public class AndroidProtocolHandler {
private static final String TAG = "AndroidProtocolHandler";
// Supported URL schemes. This needs to be kept in sync with
// clank/native/framework/chrome/url_request_android_job.cc.
private static final String FILE_SCHEME = "file";
private static final String CONTENT_SCHEME = "content";
/**
* Open an InputStream for an Android resource.
* @param context The context manager.
* @param url The url to load.
* @return An InputStream to the Android resource.
*/
@CalledByNative
public static InputStream open(Context context, String url) {
Uri uri = verifyUrl(url);
if (uri == null) {
return null;
}
try {
String path = uri.getPath();
if (uri.getScheme().equals(FILE_SCHEME)) {
if (path.startsWith(nativeGetAndroidAssetPath())) {
return openAsset(context, uri);
} else if (path.startsWith(nativeGetAndroidResourcePath())) {
return openResource(context, uri);
}
} else if (uri.getScheme().equals(CONTENT_SCHEME)) {
return openContent(context, uri);
}
} catch (Exception ex) {
Log.e(TAG, "Error opening inputstream: " + url);
}
return null;
}
private static int getFieldId(Context context, String assetType, String assetName)
throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
Class<?> d = context.getClassLoader()
.loadClass(context.getPackageName() + ".R$" + assetType);
java.lang.reflect.Field field = d.getField(assetName);
int id = field.getInt(null);
return id;
}
private static int getValueType(Context context, int fieldId) {
TypedValue value = new TypedValue();
context.getResources().getValue(fieldId, value, true);
return value.type;
}
private static InputStream openResource(Context context, Uri uri) {
assert uri.getScheme().equals(FILE_SCHEME);
assert uri.getPath() != null;
assert uri.getPath().startsWith(nativeGetAndroidResourcePath());
// The path must be of the form "/android_res/asset_type/asset_name.ext".
List<String> pathSegments = uri.getPathSegments();
if (pathSegments.size() != 3) {
Log.e(TAG, "Incorrect resource path: " + uri);
return null;
}
String assetPath = pathSegments.get(0);
String assetType = pathSegments.get(1);
String assetName = pathSegments.get(2);
if (!("/" + assetPath + "/").equals(nativeGetAndroidResourcePath())) {
Log.e(TAG, "Resource path does not start with " + nativeGetAndroidResourcePath() +
": " + uri);
return null;
}
// Drop the file extension.
assetName = assetName.split("\\.")[0];
try {
// Use the application context for resolving the resource package name so that we do
// not use the browser's own resources. Note that if 'context' here belongs to the
// test suite, it does not have a separate application context. In that case we use
// the original context object directly.
if (context.getApplicationContext() != null) {
context = context.getApplicationContext();
}
int fieldId = getFieldId(context, assetType, assetName);
int valueType = getValueType(context, fieldId);
if (valueType == TypedValue.TYPE_STRING) {
return context.getResources().openRawResource(fieldId);
} else {
Log.e(TAG, "Asset not of type string: " + uri);
return null;
}
} catch (ClassNotFoundException e) {
Log.e(TAG, "Unable to open resource URL: " + uri, e);
return null;
} catch (NoSuchFieldException e) {
Log.e(TAG, "Unable to open resource URL: " + uri, e);
return null;
} catch (IllegalAccessException e) {
Log.e(TAG, "Unable to open resource URL: " + uri, e);
return null;
}
}
private static InputStream openAsset(Context context, Uri uri) {
assert uri.getScheme().equals(FILE_SCHEME);
assert uri.getPath() != null;
assert uri.getPath().startsWith(nativeGetAndroidAssetPath());
String path = uri.getPath().replaceFirst(nativeGetAndroidAssetPath(), "");
try {
AssetManager assets = context.getAssets();
return assets.open(path, AssetManager.ACCESS_STREAMING);
} catch (IOException e) {
Log.e(TAG, "Unable to open asset URL: " + uri);
return null;
}
}
private static InputStream openContent(Context context, Uri uri) {
assert uri.getScheme().equals(CONTENT_SCHEME);
try {
return context.getContentResolver().openInputStream(uri);
} catch (Exception e) {
Log.e(TAG, "Unable to open content URL: " + uri);
return null;
}
}
/**
* Determine the mime type for an Android resource.
* @param context The context manager.
* @param stream The opened input stream which to examine.
* @param url The url from which the stream was opened.
* @return The mime type or null if the type is unknown.
*/
@CalledByNative
public static String getMimeType(Context context, InputStream stream, String url) {
Uri uri = verifyUrl(url);
if (uri == null) {
return null;
}
try {
String path = uri.getPath();
// The content URL type can be queried directly.
if (uri.getScheme().equals(CONTENT_SCHEME)) {
return context.getContentResolver().getType(uri);
// Asset files may have a known extension.
} else if (uri.getScheme().equals(FILE_SCHEME) &&
path.startsWith(nativeGetAndroidAssetPath())) {
String mimeType = URLConnection.guessContentTypeFromName(path);
if (mimeType != null) {
return mimeType;
}
}
} catch (Exception ex) {
Log.e(TAG, "Unable to get mime type" + url);
return null;
}
// Fall back to sniffing the type from the stream.
try {
return URLConnection.guessContentTypeFromStream(stream);
} catch (IOException e) {
return null;
}
}
/**
* Make sure the given string URL is correctly formed and parse it into a Uri.
* @return a Uri instance, or null if the URL was invalid.
*/
private static Uri verifyUrl(String url) {
if (url == null) {
return null;
}
Uri uri = Uri.parse(url);
if (uri == null) {
Log.e(TAG, "Malformed URL: " + url);
return null;
}
String path = uri.getPath();
if (path == null || path.length() == 0) {
Log.e(TAG, "URL does not have a path: " + url);
return null;
}
return uri;
}
/**
* Set the context to be used for resolving resource queries.
* @param context Context to be used, or null for the default application
* context.
*/
public static void setResourceContextForTesting(Context context) {
nativeSetResourceContextForTesting(context);
}
private static native void nativeSetResourceContextForTesting(Context context);
private static native String nativeGetAndroidAssetPath();
private static native String nativeGetAndroidResourcePath();
}