Android example source code file (ContentLoader.java)

This example Android source code file (ContentLoader.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, contentloader, http, internet, loadlistener, net, network, ok, override, runtimeexception, streamloader, string, uri

The ContentLoader.java Android example source code

/*
 * Copyright (C) 2008 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 android.webkit;

import android.net.http.EventHandler;
import android.net.http.Headers;
import android.net.Uri;

/**
 * This class is a concrete implementation of StreamLoader that loads
 * "content:" URIs
 */
class ContentLoader extends StreamLoader {

    private String mUrl;
    private String mContentType;

    /**
     * Construct a ContentLoader with the specified content URI
     *
     * @param rawUrl "content:" url pointing to content to be loaded. This url
     *               is the same url passed in to the WebView.
     * @param loadListener LoadListener to pass the content to
     */
    ContentLoader(String rawUrl, LoadListener loadListener) {
        super(loadListener);

        /* strip off mimetype */
        int mimeIndex = rawUrl.lastIndexOf('?');
        if (mimeIndex != -1) {
            mUrl = rawUrl.substring(0, mimeIndex);
            mContentType = rawUrl.substring(mimeIndex + 1);
        } else {
            mUrl = rawUrl;
        }

    }

    private String errString(Exception ex) {
        String exMessage = ex.getMessage();
        String errString = mContext.getString(
                com.android.internal.R.string.httpErrorFileNotFound);
        if (exMessage != null) {
            errString += " " + exMessage;
        }
        return errString;
    }

    @Override
    protected boolean setupStreamAndSendStatus() {
        Uri uri = Uri.parse(mUrl);
        if (uri == null) {
            mLoadListener.error(
                    EventHandler.FILE_NOT_FOUND_ERROR,
                    mContext.getString(
                            com.android.internal.R.string.httpErrorBadUrl) +
                    " " + mUrl);
            return false;
        }

        try {
            mDataStream = mContext.getContentResolver().openInputStream(uri);
            mLoadListener.status(1, 1, 200, "OK");
        } catch (java.io.FileNotFoundException ex) {
            mLoadListener.error(EventHandler.FILE_NOT_FOUND_ERROR, errString(ex));
            return false;
        } catch (RuntimeException ex) {
            // readExceptionWithFileNotFoundExceptionFromParcel in DatabaseUtils
            // can throw a serial of RuntimeException. Catch them all here.
            mLoadListener.error(EventHandler.FILE_ERROR, errString(ex));
            return false;
        }
        return true;
    }

    @Override
    protected void buildHeaders(Headers headers) {
        if (mContentType != null) {
            headers.setContentType("text/html");
        }
        // content can change, we don't want WebKit to cache it
        headers.setCacheControl("no-store, no-cache");
    }
}