com.github.snowdream.android.widget.NotFoundWebView.java Source code

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Here is the source code for com.github.snowdream.android.widget.NotFoundWebView.java

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/*******************************************************************************
 * Copyright (C) 2013 Snowdream Mobile
 *
 * 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.github.snowdream.android.widget;

import java.io.IOException;
import java.util.Map;

import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpHead;
import org.apache.http.impl.client.DefaultHttpClient;

import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.AsyncTask;
import android.util.AttributeSet;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebSettings.ZoomDensity;

/**
 * A Webview when 404 errors occour,will show the public service advertisement.
 * 
 * @author snowdream <yanghui1986527@gmail.com>
 * @date 2013-7-9
 * @version v1.0
 */
public class NotFoundWebView extends WebView {
    private String script = null;

    /**
     * @param context
     * @param attrs
     * @param defStyle
     */
    public NotFoundWebView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init(context, attrs, defStyle);
    }

    /**
     * @param context
     * @param attrs
     */
    public NotFoundWebView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context, attrs, 0);
    }

    /**
     * @param context
     */
    public NotFoundWebView(Context context) {
        super(context);
        init(context, null, 0);
    }

    @SuppressLint({ "SetJavaScriptEnabled", "NewApi" })
    private void init(Context context, AttributeSet attrs, int defStyle) {
        if (context == null) {
            return;
        }

        // enable JavaScript
        WebSettings settings = this.getSettings();
        settings.setJavaScriptEnabled(true);

        settings.setSupportZoom(true);
        settings.setBuiltInZoomControls(true);
        settings.setLoadWithOverviewMode(true);
        settings.setDefaultZoom(ZoomDensity.FAR);

        //settings.setUseWideViewPort(true);
        //webView.setInitialScale(1);

        // init attrs
        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.CustomWebView);

        try {
            int type = a.getInteger(R.styleable.CustomWebView_type, 0);
            switch (type) {
            case 0:
                script = context.getString(R.string.html_notfound);
                break;
            case 1:
                script = context.getString(R.string.html_qq_narrow);
                break;
            case 2:
                script = context.getString(R.string.html_qq_narrow);
                break;
            case 3:
                script = context.getString(R.string.html_qq_wide);
                break;
            case 4:
                script = context.getString(R.string.html_yibo);
                break;
            default:
                script = a.getString(R.styleable.CustomWebView_script);
                break;
            }
        } finally {
            a.recycle();
        }
    }

    private void showNotFoundPage() {
        String html = getNotFoundPageHtml();
        this.loadData(html, "text/html", "UTF-8");
    }

    private String getNotFoundPageHtml() {
        String body = "";

        if (script != null && script != "") {
            body = script;
        }

        return HtmlUtil.getHtml(body);
    }

    @Override
    public void loadUrl(String url) {
        new loadUrlTask().execute(url);
    }

    private void loadSuperUrl(String url) {
        super.loadUrl(url);
    }

    @SuppressLint("NewApi")
    @Override
    public void loadUrl(String url, Map<String, String> additionalHttpHeaders) {
        new loadUrlTask().execute(url, additionalHttpHeaders);
    }

    @SuppressLint("NewApi")
    private void loadSuperUrl(String url, Map<String, String> additionalHttpHeaders) {
        super.loadUrl(url, additionalHttpHeaders);
    }

    /**
     * Check the status code
     * 
     * @param url
     * @return status code
     */
    private int getRespStatus(String url) {
        int status = -1;
        try {
            HttpHead head = new HttpHead(url);
            HttpClient client = new DefaultHttpClient();
            HttpResponse resp = client.execute(head);
            status = resp.getStatusLine().getStatusCode();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return status;
    }

    private class loadUrlTask extends AsyncTask<Object, Void, Void> {

        @SuppressWarnings("unchecked")
        @Override
        protected Void doInBackground(Object... params) {
            if (params == null || params.length < 1) {
                return null;
            }
            String url = null;
            Map<String, String> additionalHttpHeaders = null;

            if (params.length > 0) {
                url = (String) params[0];
            }

            if (params.length > 1) {
                additionalHttpHeaders = (Map<String, String>) params[1];
            }

            if (url == null || url == "") {
                return null;
            }

            if (getRespStatus(url) == HttpStatus.SC_NOT_FOUND) {
                showNotFoundPage();
            } else {
                if (additionalHttpHeaders != null) {
                    loadSuperUrl(url, additionalHttpHeaders);
                } else {
                    loadSuperUrl(url);
                }
            }

            return null;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
        }

    }
}