android 编写简单浏览器带下载

black library 2011-11-08
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android 编写简单浏览器带下载

2011-06-01 14:16 45人阅读评论(0) 收藏举报
android 编写简单浏览器带下载 支持多触点 支持下载功能
转自：http://www./html/2182.html
package org.badboy.browser;  
 
import java.io.ByteArrayOutputStream;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileNotFoundException;  
import java.io.FileOutputStream;  
import java.io.InputStream;  
import java.net.HttpURLConnection;  
import java.net.MalformedURLException;  
import java.net.URL;  
import java.net.URLConnection;  
 
import org.metalev.multitouch.controller.MultiTouchController;  
import org.metalev.multitouch.controller.MultiTouchController.MultiTouchObjectCanvas;  
import org.metalev.multitouch.controller.MultiTouchController.PointInfo;  
import org.metalev.multitouch.controller.MultiTouchController.PositionAndScale;  
 
import android.app.Activity;  
import android.app.AlertDialog;  
import android.app.Dialog;  
import android.app.ProgressDialog;  
import android.app.SearchManager;  
import android.content.Context;  
import android.content.Intent;  
import android.content.res.Configuration;  
import android.net.Uri;  
import android.os.Bundle;  
import android.os.Environment;  
import android.util.Log;  
import android.view.KeyEvent;  
import android.view.Menu;  
import android.view.MenuItem;  
import android.view.MotionEvent;  
import android.view.View;  
import android.view.Window;  
import android.webkit.DownloadListener;  
import android.webkit.URLUtil;  
import android.webkit.WebChromeClient;  
import android.webkit.WebView;  
import android.webkit.WebViewClient;  
import android.widget.Button;  
import android.widget.EditText;  
import android.widget.ProgressBar;  
import android.widget.Toast;  
 
/***  
* 使用WebView对象创建一个简单网页浏览器。  
* @author BadBoy  
*  
*/ 
public class BrowserActivity extends Activity implements MultiTouchObjectCanvas<Object>{  
          
        private final static int MENU_NEW_WEB = Menu.FIRST;  
        private final static int MENU_SET_MAIN_PAGE = MENU_NEW_WEB + 1;  
          
        private String defaultGoogleUrl = "";  
        private String defaultUCWebUrl = "";  
        private String defaultUrl = "";  
        private WebView mWebView;  
        //储存默认网址文件  
        private String fileUrl = "fileUrl.txt";  
        //对话框标识  
        private final static int PROGRESS_DIALOG = 110;  
        private final static int SET_DEFAULT_URL_DIALOG = 111;  
        //显示网页加载进度  
        private ProgressDialog mDialog;  
        private ProgressBar bar;  
        //多点触摸  
        private MultiTouchController<Object> mMultiTouchController;  
        @Override 
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        //下面四条语句要在setContentView()方法之前调用，否则程序会出错，在本程序中，加入以下的语句貌似还没有什么影响,或者有我还没发现  
        this.requestWindowFeature(Window.FEATURE_LEFT_ICON);  
        this.requestWindowFeature(Window.FEATURE_RIGHT_ICON);  
        this.requestWindowFeature(Window.FEATURE_PROGRESS);  
        this.requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);  
          
        setContentView(R.layout.main);  
        initWebView();  
        performSearchIntent(getIntent());  
          
          
    }  
          
        @Override 
        protected void onNewIntent(Intent intent) {  
                setIntent(intent);  
                performSearchIntent(intent);  
        }  
        /**  
         * 执行搜索，打开网页  
         */ 
        private void performSearchIntent(Intent intent) {  
                if(Intent.ACTION_SEARCH.equals(intent.getAction())){  
                String query = intent.getStringExtra(SearchManager.QUERY);  
                //还没有对网址进行严格的解析  
                if(!query.startsWith("http://")){  
                        mWebView.loadUrl("http://"+query);  
                }  
                if(query.startsWith("http://")){  
                        mWebView.loadUrl(query);  
                }  
                /*else{  
                        Toast.makeText(this, R.string.url_error, Toast.LENGTH_SHORT).show();  
                }*/ 
        }  
        }  
          
        private void initWebView() {  
                defaultGoogleUrl = this.getResources().getString(R.string.default_google_url);  
                defaultUCWebUrl = this.getResources().getString(R.string.default_ucweb_url);  
                setDefaultURL();  
                  
                bar = (ProgressBar)findViewById(R.id.progress_bar);  
                  
                mMultiTouchController = new MultiTouchController<Object>(this,false);  
                  
                mWebView = (WebView)findViewById(R.id.webview);  
        //使用mWebView的getSettings()方法设置支持JavaScript为true  
        mWebView.getSettings().setJavaScriptEnabled(true);  
        mWebView.setScrollBarStyle(0);  
        //用loadUrl方法加载网址  
        mWebView.loadUrl(defaultUrl);  
        //对mWebView设置WebViewClient对象,如果不设置此对象那么当单击mWebView中的链接时将由系统 
        //默认的Browser来响应链接，即由默认的Browser打开链接，而不是你自己写的Browser来打开  
        //故为了mWebView自己处理页面中的所有链接，则要扩展WebViewClient类，重载shouldOverrideUrlLoading()方法  
        mWebView.setWebViewClient(new MyWebViewClient());  
        //  
        mWebView.setWebChromeClient(new MyWebChromeClient());  
        //实现下载监听  
                mWebView.setDownloadListener(new DownloadListener(){  
 
                        public void onDownloadStart(String url, String userAgent, String contentDisposition,  
                                        String mimetype, long contentLength) {  
                                /*Uri uri = Uri.parse(url);  
                                Intent intent = new Intent(Intent.ACTION_VIEW,uri);  
                                startActivity(intent);  
                                */ 
                                downloadFile(url, mimetype, mimetype, mimetype, contentLength);  
                        }  
                          
                });  
        }  
        /*  
         * 下列代码实现网络文件下载功能，目前下载的文件时存储在/data/data/org.badboy.browser/files目录下的。  
         * 后续还会更新这个方法，将其下载到SDCard上来。思路是这样子的：下载文件时先检查是否由sdcard或udisk外存储设备，  
         * 若有则直接下载到外存储设备，否则存储到/data/data/org.badboy.browser/files目录中。最后还要增加一个功能：就是  
         * 列出已下载文件，以及对文件copy，delete等操作  
         * 2011-3-4  
         */ 
        private void downloadFile(String url,String userAgent, String contentDisposition,  
                        String mimetype, long contentLength) {  
                  
                /*String filename = URLUtil.guessFileName(url,  
                contentDisposition, mimetype);  
                // Check to see if we have an SDCard  
        String status = Environment.getExternalStorageState();  
        if (!status.equals(Environment.MEDIA_MOUNTED)) {  
            int title;  
            String msg;  
 
            // Check to see if the SDCard is busy, same as the music app  
            if (status.equals(Environment.MEDIA_SHARED)) {  
                msg = getString(R.string.download_sdcard_busy_dlg_msg);  
                title = R.string.download_sdcard_busy_dlg_title;  
            } else {  
                msg = getString(R.string.download_no_sdcard_dlg_msg, filename);  
                title = R.string.download_no_sdcard_dlg_title;  
            }  
 
            new AlertDialog.Builder(this)  
                .setTitle(title)  
                .setIcon(android.R.drawable.ic_dialog_alert)  
                .setMessage(msg)  
                .setPositiveButton(R.string.ok, null)  
                .show();  
            return;  
        }*/ 
                  
                try {  
                        String filename = URLUtil.guessFileName(url,  
                        contentDisposition, mimetype);  
                        URL url2 = new URL(url);  
                        HttpURLConnection conn = (HttpURLConnection) url2.openConnection();  
                        conn.setDoInput(true);  
                        conn.connect();  
                        if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {  
                                InputStream is = conn.getInputStream();  
                                FileOutputStream fos = this.openFileOutput(filename, Context.MODE_APPEND);  
                                int len = 0;  
                                byte[] buf = new byte[1024];  
                                while ((len = is.read(buf)) != -1) {  
                                        fos.write(buf, 0, len);  
                                }  
                                is.close();  
                                fos.close();  
                        } else {  
                                Toast.makeText(this, R.string.net_error, Toast.LENGTH_SHORT).show();  
                        }  
 
                } catch (Exception e) {  
                        e.printStackTrace();  
                }  
                  
        }  
 
        private void setDefaultURL() {  
                try {  
                        //android中使用openFileInput()方法得到文件输入流  
                        FileInputStream fis = this.openFileInput(fileUrl);  
                        ByteArrayOutputStream baos = new ByteArrayOutputStream();  
                        byte[] buffer = new byte[1024];  
                        int len = 0;  
                        while((len = fis.read(buffer))!=-1){  
                                baos.write(buffer, 0, len);  
                        }  
                        //defaultUrl = new String(buffer,0,len);  
                        defaultUrl = baos.toString();  
                        fis.close();  
                        baos.close();  
                } catch (Exception e) {  
                        e.printStackTrace();  
                }  
                //如果还是为空，则使用defaultUCWebUrl  
                if(defaultUrl.equals("")){  
                        defaultUrl = defaultUCWebUrl;  
                }  
        }  
        /**  
         * 按键事件处理  
         */ 
        @Override 
        public boolean onKeyDown(int keyCode, KeyEvent event) {  
                //按返回键可退回之前浏览过的网页  
                if((keyCode == KeyEvent.KEYCODE_BACK) && mWebView.canGoBack()){  
                        mWebView.goBack();  
                        return true;  
                }  
                //搜索按键  
                if(keyCode == KeyEvent.KEYCODE_SEARCH){  
                        onSearchRequested();  
                }  
                return super.onKeyDown(keyCode, event);  
        }  
        /**  
         * 重写WebChromeClient类  
         */ 
        private class MyWebChromeClient extends WebChromeClient {  
                //设置网页加载进度条  
                @Override 
                public void onProgressChanged(WebView webview, int newProgress){  
                        BrowserActivity.this.getWindow().setFeatureInt(Window.FEATURE_PROGRESS, 100);  
                        //以下注释代码是用来ProgressDialog显示网页加载进度的  
                        /*showDialog(PROGRESS_DIALOG);  
                        mDialog.setProgress(newProgress);  
                        if(newProgress==100){  
                                dismissDialog(PROGRESS_DIALOG);  
                        }*/ 
                        //以下代码是用来ProgressBar显示网页加载进度的  
                        bar.setProgress(newProgress);  
                        bar.setVisibility(View.VISIBLE);  
                        if(bar.getProgress()==100){  
                                bar.setVisibility(View.GONE);  
                        }  
                        super.onProgressChanged(webview, newProgress);  
                }  
        }  
        /**  
         * 重写 WebViewClient类,由本Browser处理网页中的链接  
         */ 
        private class MyWebViewClient extends WebViewClient {  
 
                @Override 
                public boolean shouldOverrideUrlLoading(WebView view, String url) {  
                        view.loadUrl(url);  
                        return true;  
                }  
                  
        }  
        /**  
         * Menu 按键的添加和事件处理  
         */ 
        @Override 
        public boolean onCreateOptionsMenu(Menu menu) {  
                //打开网址输入栏  
                menu.add(0,MENU_NEW_WEB,0,R.string.new_web_page)  
                        .setIcon(R.drawable.search_icon);  
                //设置默认网址  
                menu.add(0,MENU_SET_MAIN_PAGE,0,R.string.set_default_url)  
                .setIcon(R.drawable.browser_icon);  
                return super.onCreateOptionsMenu(menu);  
        }  
        @Override 
        public boolean onMenuItemSelected(int featureId, MenuItem item) {  
                switch(item.getItemId()){  
                case MENU_NEW_WEB:  
                        onSearchRequested();  
                        return true;  
                case MENU_SET_MAIN_PAGE:  
                        this.showDialog(SET_DEFAULT_URL_DIALOG);  
                        break;  
                }  
                return super.onMenuItemSelected(featureId, item);  
        }  
          
        /**  
         * 重写onSearchRequested(),可实现调用Search Bar  
         */ 
        @Override 
        public boolean onSearchRequested() {  
                //本程序还没处理Bundle对象传来的数据，注释下列三行代码  
                /*Bundle appData = new Bundle();  
                appData.putBoolean("search",true);  
                this.startSearch(null, false, appData, false);*/ 
                this.startSearch(null, false, null, false);  
                return true;  
        }  
        /**  
         * 当要调用this.showDialog(int id)方法来显示Dialog时，要重写下列方法  
         */ 
        @Override 
        protected Dialog onCreateDialog(int id) {  
                switch(id){  
                case PROGRESS_DIALOG:  
                        mDialog = new ProgressDialog(this);  
                        //mDialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);  
                        mDialog.setMessage("Page is loading...");  
                        return mDialog;  
                case SET_DEFAULT_URL_DIALOG:  
                        return createDefaultUrlDialog();  
                default:  
                        return super.onCreateDialog(id);  
                }  
                  
        }  
        private Dialog createDefaultUrlDialog() {  
                final Dialog dialog = new Dialog(this);  
                dialog.setContentView(R.layout.default_url_dialog);  
                dialog.setTitle(R.string.dialog_title);  
                final EditText url = (EditText)dialog.findViewById(R.id.url);  
                Button btnOK = (Button)dialog.findViewById(R.id.ok_btn);  
                btnOK.setOnClickListener(new View.OnClickListener() {  
                          
                        public void onClick(View arg0) {  
                                defaultUrl = url.getText().toString();  
                                try {  
                                        FileOutputStream fos = BrowserActivity.this.openFileOutput(fileUrl, Context.MODE_PRIVATE);  
                                        byte[] buffer = defaultUrl.getBytes();  
                                        fos.write(buffer);  
                                        fos.close();  
                                } catch (Exception e) {  
                                        e.printStackTrace();  
                                }  
                                dialog.dismiss();  
                                mWebView.loadUrl(defaultUrl);  
                        }  
                });  
                Button btnCancel = (Button)dialog.findViewById(R.id.cancel_btn);  
                btnCancel.setOnClickListener(new View.OnClickListener() {  
                          
                        public void onClick(View arg0) {  
                                dialog.dismiss();  
                        }  
                });  
                return dialog;  
        }  
 
        /**  
         * 屏幕旋转时，程序会重新调用onCreate()方法，即重新加载程序。当不需要这么做时，  
         * 可在manifest文件中的Activity标签中加入android:configChanges="orientation|keyboardHidden"  
         * 属性，并且重写下列方法。该方法中可以处理屏幕旋转时发生的动作  
         */ 
        @Override 
        public void onConfigurationChanged(Configuration newConfig) {  
                  
                /*if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) { 
                          
                } else if (this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) { 
                          
                }*/ 
 
                super.onConfigurationChanged(newConfig);  
        }  
          
        //-------------multitouch stuff ------------------------------------  
          
        private int mCurrentZoom = 0;  
        private static final double ZOOM_SENSITIVITY = 1.6;  
        private static final float ZOOM_LOG_BASE_INV = 1.0f / (float) Math.log(2.0 / ZOOM_SENSITIVITY);  
        private boolean isMultiTouchScale = false;  
        @Override   
        public boolean dispatchTouchEvent(MotionEvent event) {  
                if (mMultiTouchController.onTouchEvent(event)) {  
                        if (!isMultiTouchScale) {  
                                event.setAction(MotionEvent.ACTION_CANCEL);  
                                super.dispatchTouchEvent(event);  
                        }  
                }else{  
                        isMultiTouchScale = true;  
                         if (super.dispatchTouchEvent(event)) {  
                                 return true;  
                         }  
                         return false;  
                }  
                return true;  
        }  
        public Object getDraggableObjectAtPoint(PointInfo touchPoint) {  
                return new Object();  
        }  
 
        public void getPositionAndScale(Object obj,  
                        PositionAndScale objPosAndScaleOut) {  
                objPosAndScaleOut.set(0.0f, 0.0f, true, 1.0f, false, 0.0f, 0.0f, false, 0.0f);  
                mCurrentZoom = 0;  
        }  
 
        public void selectObject(Object obj, PointInfo touchPoint) {  
                  
        }  
 
        public boolean setPositionAndScale(Object obj,  
                        PositionAndScale newObjPosAndScale, PointInfo touchPoint) {  
                float newRelativeScale = newObjPosAndScale.getScale();  
                int targetZoom = (int) Math.round(Math.log(newRelativeScale)  
                                * ZOOM_LOG_BASE_INV);  
                while (mCurrentZoom > targetZoom) {  
                        mCurrentZoom--;  
                        mWebView.zoomOut();  
                }  
                while (mCurrentZoom < targetZoom) {  
                        mCurrentZoom++;  
                        mWebView.zoomIn();  
                }  
                return true;  
        }  
          
}