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安卓使用WebView下载文件,安卓实现软件升级功能

时间:2014-10-16 02:18:12      阅读:441      评论:0      收藏:0      [点我收藏+]

标签:安卓   webview   线程   安卓更新功能   

因为调用系统默认浏览器下载更新,造成用户体验很不好,所以决定在webview中直接下载系统更新,然后直接安装。

因为要下载,所以必须用webview,联网权限这里不说了,直接写在manifafest中。

我们常用的下载都是调用Android默认浏览器 这样写


 1、设置WebView的DownloadListener:

    webView.setDownloadListener(new MyWebViewDownLoadListener());

    2、实现MyWebViewDownLoadListener这个类,具体可以如下这样:    

[java] view plaincopy
  1. private class MyWebViewDownLoadListener implements DownloadListener {  
  2.   
  3.         @Override  
  4.         public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype,  
  5.                                     long contentLength) {  
  6.             Uri uri = Uri.parse(url);  
  7.             Intent intent = new Intent(Intent.ACTION_VIEW, uri);  
  8.             startActivity(intent);  
  9.         }  
  10.   
  11.     }  


为了直接下载,

Sample:

java代码:

  

public class zwebxiazai extends Activity {
   
 WebView webView;
   
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.webView=(WebView) this.findViewById(R.id.webview);
        this.webView.getSettings().setSupportZoom(false);
        this.webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
        this.webView.loadUrl("http://a.zntx.cc/");
        this.webView.setWebViewClient(new WebViewClientDemo());
        webView.setDownloadListener(new DownloadListener() {
            public void onDownloadStart(String url, String userAgent,
                            String contentDisposition, String mimetype,
                            long contentLength) {
                    //实现下载的代码
                                          Uri uri = Uri.parse(url);
           Intent intent = new Intent(Intent.ACTION_VIEW,uri);
                    startActivity(intent);
            }
    });


    }
  private class WebViewClientDemo extends WebViewClient {
    @Override
    // 在WebView中而不是默认浏览器中显示页面
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
     view.loadUrl(url);
      return true;
     }

     

    }
  }

 


main.xml代码:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<TextView
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="@string/hello"
    />
<WebView android:id="@+id/webview" android:layout_width="fill_parent"
    android:layout_height="0dip" android:layout_weight="1" />


</LinearLayout>

在AndroidManifest.xml中加入访问internet的权限:

<uses-permission android:name="android.permission.INTERNET"></uses-permission>


Sample2   这个比较详细  

WebView控制调用相应的WEB页面进行展示。当碰到页面有下载链接的时候,点击上去是一点反应都没有的。原来是因为WebView默认没有开启文件下载的功能,如果要实现文件下载的功能,需要设置WebView的DownloadListener,通过实现自己的DownloadListener来实现文件的下载。具体操作如下: 

1、设置WebView的DownloadListener: 
    webView.setDownloadListener(new MyWebViewDownLoadListener()); 

2、实现MyWebViewDownLoadListener这个类,具体可以如下这样:  

Java代码 bubuko.com,布布扣 bubuko.com,布布扣bubuko.com,布布扣
  1. private class MyWebViewDownLoadListener implements DownloadListener{   
  2.   
  3.         @Override  
  4.         public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype,   
  5.                                     long contentLength) {              
  6.             Log.i("tag""url="+url);              
  7.             Log.i("tag""userAgent="+userAgent);   
  8.             Log.i("tag""contentDisposition="+contentDisposition);            
  9.             Log.i("tag""mimetype="+mimetype);   
  10.             Log.i("tag""contentLength="+contentLength);   
  11.             Uri uri = Uri.parse(url);   
  12.             Intent intent = new Intent(Intent.ACTION_VIEW, uri);   
  13.             startActivity(intent);              
  14.         }   
  15.     }  
[java] view plaincopy
  1. private class MyWebViewDownLoadListener implements DownloadListener{  
  2.   
  3.         @Override  
  4.         public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype,  
  5.                                     long contentLength) {             
  6.             Log.i("tag""url="+url);             
  7.             Log.i("tag""userAgent="+userAgent);  
  8.             Log.i("tag""contentDisposition="+contentDisposition);           
  9.             Log.i("tag""mimetype="+mimetype);  
  10.             Log.i("tag""contentLength="+contentLength);  
  11.             Uri uri = Uri.parse(url);  
  12.             Intent intent = new Intent(Intent.ACTION_VIEW, uri);  
  13.             startActivity(intent);             
  14.         }  
  15.     }  

  这只是调用系统中已经内置的浏览器进行下载,还没有WebView本身进行的文件下载,不过,这也基本上满足我们的应用场景了。 

我在项目中的运用 
项目要求这样: 
1,需要使用WebView加载一个网页; 
2,网页中有文件下载的链接,点击后需要下载文件到SDcard; 
3,然后自动打开文件; 
下面是具体解决办法 
第一步,对WebView进行一系列设置。 

Java代码 bubuko.com,布布扣 bubuko.com,布布扣bubuko.com,布布扣
  1. WebView webview=(WebView)layout.findViewById(R.id.webview);   
  2.                 webview.getSettings().setJavaScriptEnabled(true);   
  3.                 webview.setWebChromeClient(new MyWebChromeClient());   
  4.                 webview.requestFocus();   
  5. //              webview.loadUrl("file:///android_asset/risktest.html");   
  6.                 webview.loadUrl(jcrs_sub.get(position).addr);   
  7.                 // 设置web视图客户端   
  8.                 webview.setWebViewClient(new MyWebViewClient());   
  9.                 webview.setDownloadListener(new MyWebViewDownLoadListener());   
  10.   
  11. //内部类   
  12. public class MyWebViewClient extends WebViewClient {   
  13.         // 如果页面中链接,如果希望点击链接继续在当前browser中响应,   
  14.         // 而不是新开Android的系统browser中响应该链接,必须覆盖 webview的WebViewClient对象。   
  15.         public boolean shouldOverviewUrlLoading(WebView view, String url) {   
  16.             L.i("shouldOverviewUrlLoading");   
  17.             view.loadUrl(url);   
  18.             return true;   
  19.         }   
  20.   
  21.         public void onPageStarted(WebView view, String url, Bitmap favicon) {   
  22.             L.i("onPageStarted");   
  23.             showProgress();   
  24.         }   
  25.   
  26.         public void onPageFinished(WebView view, String url) {   
  27.             L.i("onPageFinished");   
  28.             closeProgress();   
  29.         }   
  30.   
  31.         public void onReceivedError(WebView view, int errorCode,   
  32.                 String description, String failingUrl) {   
  33.             L.i("onReceivedError");   
  34.             closeProgress();   
  35.         }   
  36.     }   
  37.   
  38. // 如果不做任何处理,浏览网页,点击系统“Back”键,整个Browser会调用finish()而结束自身,   
  39.     // 如果希望浏览的网 页回退而不是推出浏览器,需要在当前Activity中处理并消费掉该Back事件。   
  40.     public boolean onKeyDown(int keyCode, KeyEvent event) {   
  41.         // if((keyCode==KeyEvent.KEYCODE_BACK)&&webview.canGoBack()){   
  42.         // webview.goBack();   
  43.         // return true;   
  44.         // }   
  45.         return false;   
  46.     }  
[java] view plaincopy
  1. WebView webview=(WebView)layout.findViewById(R.id.webview);  
  2.                 webview.getSettings().setJavaScriptEnabled(true);  
  3.                 webview.setWebChromeClient(new MyWebChromeClient());  
  4.                 webview.requestFocus();  
  5. //              webview.loadUrl("file:///android_asset/risktest.html");  
  6.                 webview.loadUrl(jcrs_sub.get(position).addr);  
  7.                 // 设置web视图客户端  
  8.                 webview.setWebViewClient(new MyWebViewClient());  
  9.                 webview.setDownloadListener(new MyWebViewDownLoadListener());  
  10.   
  11. //内部类  
  12. public class MyWebViewClient extends WebViewClient {  
  13.         // 如果页面中链接,如果希望点击链接继续在当前browser中响应,  
  14.         // 而不是新开Android的系统browser中响应该链接,必须覆盖 webview的WebViewClient对象。  
  15.         public boolean shouldOverviewUrlLoading(WebView view, String url) {  
  16.             L.i("shouldOverviewUrlLoading");  
  17.             view.loadUrl(url);  
  18.             return true;  
  19.         }  
  20.   
  21.         public void onPageStarted(WebView view, String url, Bitmap favicon) {  
  22.             L.i("onPageStarted");  
  23.             showProgress();  
  24.         }  
  25.   
  26.         public void onPageFinished(WebView view, String url) {  
  27.             L.i("onPageFinished");  
  28.             closeProgress();  
  29.         }  
  30.   
  31.         public void onReceivedError(WebView view, int errorCode,  
  32.                 String description, String failingUrl) {  
  33.             L.i("onReceivedError");  
  34.             closeProgress();  
  35.         }  
  36.     }  
  37.   
  38. // 如果不做任何处理,浏览网页,点击系统“Back”键,整个Browser会调用finish()而结束自身,  
  39.     // 如果希望浏览的网 页回退而不是推出浏览器,需要在当前Activity中处理并消费掉该Back事件。  
  40.     public boolean onKeyDown(int keyCode, KeyEvent event) {  
  41.         // if((keyCode==KeyEvent.KEYCODE_BACK)&&webview.canGoBack()){  
  42.         // webview.goBack();  
  43.         // return true;  
  44.         // }  
  45.         return false;  
  46.     }  


第二步,起线程开始下载文件。 
Java代码 bubuko.com,布布扣 bubuko.com,布布扣bubuko.com,布布扣
  1. //内部类   
  2. private class MyWebViewDownLoadListener implements DownloadListener {   
  3.   
  4.         @Override  
  5.         public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype,   
  6.                                     long contentLength) {   
  7.             if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){   
  8.                 Toast t=Toast.makeText(mContext, "需要SD卡。", Toast.LENGTH_LONG);   
  9.                 t.setGravity(Gravity.CENTER, 00);   
  10.                 t.show();   
  11.                 return;   
  12.             }   
  13.             DownloaderTask task=new DownloaderTask();   
  14.             task.execute(url);   
  15.         }   
  16.   
  17.     }   
  18.     //内部类   
  19.     private class DownloaderTask extends AsyncTask<String, Void, String> {    
  20.   
  21.         public DownloaderTask() {    
  22.         }   
  23.   
  24.         @Override  
  25.         protected String doInBackground(String... params) {   
  26.             // TODO Auto-generated method stub   
  27.             String url=params[0];   
  28. //          Log.i("tag", "url="+url);   
  29.             String fileName=url.substring(url.lastIndexOf("/")+1);   
  30.             fileName=URLDecoder.decode(fileName);   
  31.             Log.i("tag""fileName="+fileName);   
  32.                
  33.             File directory=Environment.getExternalStorageDirectory();   
  34.             File file=new File(directory,fileName);   
  35.             if(file.exists()){   
  36.                 Log.i("tag""The file has already exists.");   
  37.                 return fileName;   
  38.             }   
  39.             try {     
  40.                 HttpClient client = new DefaultHttpClient();     
  41. //                client.getParams().setIntParameter("http.socket.timeout",3000);//设置超时  
  42.                 HttpGet get = new HttpGet(url);     
  43.                 HttpResponse response = client.execute(get);   
  44.                 if(HttpStatus.SC_OK==response.getStatusLine().getStatusCode()){   
  45.                     HttpEntity entity = response.getEntity();   
  46.                     InputStream input = entity.getContent();   
  47.                        
  48.                     writeToSDCard(fileName,input);   
  49.                        
  50.                     input.close();   
  51. //                  entity.consumeContent();   
  52.                     return fileName;     
  53.                 }else{   
  54.                     return null;   
  55.                 }   
  56.             } catch (Exception e) {     
  57.                 e.printStackTrace();   
  58.                 return null;   
  59.             }   
  60.         }   
  61.   
  62.         @Override  
  63.         protected void onCancelled() {   
  64.             // TODO Auto-generated method stub   
  65.             super.onCancelled();   
  66.         }   
  67.   
  68.         @Override  
  69.         protected void onPostExecute(String result) {   
  70.             // TODO Auto-generated method stub   
  71.             super.onPostExecute(result);   
  72.             closeProgressDialog();   
  73.             if(result==null){   
  74.                 Toast t=Toast.makeText(mContext, "连接错误!请稍后再试!", Toast.LENGTH_LONG);   
  75.                 t.setGravity(Gravity.CENTER, 00);   
  76.                 t.show();   
  77.                 return;   
  78.             }   
  79.                
  80.             Toast t=Toast.makeText(mContext, "已保存到SD卡。", Toast.LENGTH_LONG);   
  81.             t.setGravity(Gravity.CENTER, 00);   
  82.             t.show();   
  83.             File directory=Environment.getExternalStorageDirectory();   
  84.             File file=new File(directory,result);   
  85.             Log.i("tag""Path="+file.getAbsolutePath());   
  86.                
  87.             Intent intent = getFileIntent(file);   
  88.                
  89.             startActivity(intent);   
  90.                    
  91.         }   
  92.   
  93.         @Override  
  94.         protected void onPreExecute() {   
  95.             // TODO Auto-generated method stub   
  96.             super.onPreExecute();   
  97.             showProgressDialog();   
  98.         }   
  99.   
  100.         @Override  
  101.         protected void onProgressUpdate(Void... values) {   
  102.             // TODO Auto-generated method stub   
  103.             super.onProgressUpdate(values);   
  104.         }    
  105.   
  106.            
  107.     }   
[java] view plaincopy
  1. //内部类  
  2. private class MyWebViewDownLoadListener implements DownloadListener {  
  3.   
  4.         @Override  
  5.         public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype,  
  6.                                     long contentLength) {  
  7.             if(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){  
  8.                 Toast t=Toast.makeText(mContext, "需要SD卡。", Toast.LENGTH_LONG);  
  9.                 t.setGravity(Gravity.CENTER, 00);  
  10.                 t.show();  
  11.                 return;  
  12.             }  
  13.             DownloaderTask task=new DownloaderTask();  
  14.             task.execute(url);  
  15.         }  
  16.   
  17.     }  
  18.     //内部类  
  19.     private class DownloaderTask extends AsyncTask<String, Void, String> {   
  20.   
  21.         public DownloaderTask() {   
  22.         }  
  23.   
  24.         @Override  
  25.         protected String doInBackground(String... params) {  
  26.             // TODO Auto-generated method stub  
  27.             String url=params[0];  
  28. //          Log.i("tag", "url="+url);  
  29.             String fileName=url.substring(url.lastIndexOf("/")+1);  
  30.             fileName=URLDecoder.decode(fileName);  
  31.             Log.i("tag""fileName="+fileName);  
  32.               
  33.             File directory=Environment.getExternalStorageDirectory();  
  34.             File file=new File(directory,fileName);  
  35.             if(file.exists()){  
  36.                 Log.i("tag""The file has already exists.");  
  37.                 return fileName;  
  38.             }  
  39.             try {    
  40.                 HttpClient client = new DefaultHttpClient();    
  41. //                client.getParams().setIntParameter("http.socket.timeout",3000);//设置超时  
  42.                 HttpGet get = new HttpGet(url);    
  43.                 HttpResponse response = client.execute(get);  
  44.                 if(HttpStatus.SC_OK==response.getStatusLine().getStatusCode()){  
  45.                     HttpEntity entity = response.getEntity();  
  46.                     InputStream input = entity.getContent();  
  47.                       
  48.                     writeToSDCard(fileName,input);  
  49.                       
  50.                     input.close();  
  51. //                  entity.consumeContent();  
  52.                     return fileName;    
  53.                 }else{  
  54.                     return null;  
  55.                 }  
  56.             } catch (Exception e) {    
  57.                 e.printStackTrace();  
  58.                 return null;  
  59.             }  
  60.         }  
  61.   
  62.         @Override  
  63.         protected void onCancelled() {  
  64.             // TODO Auto-generated method stub  
  65.             super.onCancelled();  
  66.         }  
  67.   
  68.         @Override  
  69.         protected void onPostExecute(String result) {  
  70.             // TODO Auto-generated method stub  
  71.             super.onPostExecute(result);  
  72.             closeProgressDialog();  
  73.             if(result==null){  
  74.                 Toast t=Toast.makeText(mContext, "连接错误!请稍后再试!", Toast.LENGTH_LONG);  
  75.                 t.setGravity(Gravity.CENTER, 00);  
  76.                 t.show();  
  77.                 return;  
  78.             }  
  79.               
  80.             Toast t=Toast.makeText(mContext, "已保存到SD卡。", Toast.LENGTH_LONG);  
  81.             t.setGravity(Gravity.CENTER, 00);  
  82.             t.show();  
  83.             File directory=Environment.getExternalStorageDirectory();  
  84.             File file=new File(directory,result);  
  85.             Log.i("tag""Path="+file.getAbsolutePath());  
  86.               
  87.             Intent intent = getFileIntent(file);  
  88.               
  89.             startActivity(intent);  
  90.                   
  91.         }  
  92.   
  93.         @Override  
  94.         protected void onPreExecute() {  
  95.             // TODO Auto-generated method stub  
  96.             super.onPreExecute();  
  97.             showProgressDialog();  
  98.         }  
  99.   
  100.         @Override  
  101.         protected void onProgressUpdate(Void... values) {  
  102.             // TODO Auto-generated method stub  
  103.             super.onProgressUpdate(values);  
  104.         }   
  105.   
  106.           
  107.     }   

第三步,实现一些工具方法。 
Java代码 bubuko.com,布布扣 bubuko.com,布布扣bubuko.com,布布扣
  1. private ProgressDialog mDialog;   
  2.     private void showProgressDialog(){   
  3.         if(mDialog==null){   
  4.             mDialog = new ProgressDialog(mContext);     
  5.             mDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);//设置风格为圆形进度条     
  6.             mDialog.setMessage("正在加载 ,请等待...");     
  7.             mDialog.setIndeterminate(false);//设置进度条是否为不明确     
  8.             mDialog.setCancelable(true);//设置进度条是否可以按退回键取消     
  9.             mDialog.setCanceledOnTouchOutside(false);   
  10.             mDialog.setOnDismissListener(new OnDismissListener() {   
  11.                    
  12.                 @Override  
  13.                 public void onDismiss(DialogInterface dialog) {   
  14.                     // TODO Auto-generated method stub   
  15.                     mDialog=null;   
  16.                 }   
  17.             });   
  18.             mDialog.show();   
  19.                
  20.         }   
  21.     }   
  22.     private void closeProgressDialog(){   
  23.         if(mDialog!=null){   
  24.             mDialog.dismiss();   
  25.             mDialog=null;   
  26.         }   
  27.     }   
  28.      public Intent getFileIntent(File file){   
  29. //       Uri uri = Uri.parse("http://m.ql18.com.cn/hpf10/1.pdf");   
  30.         Uri uri = Uri.fromFile(file);   
  31.         String type = getMIMEType(file);   
  32.         Log.i("tag""type="+type);   
  33.         Intent intent = new Intent("android.intent.action.VIEW");   
  34.         intent.addCategory("android.intent.category.DEFAULT");   
  35.         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);   
  36.         intent.setDataAndType(uri, type);   
  37.         return intent;   
  38.       }   
  39.         
  40.     public void writeToSDCard(String fileName,InputStream input){   
  41.            
  42.         if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){   
  43.             File directory=Environment.getExternalStorageDirectory();   
  44.             File file=new File(directory,fileName);   
  45. //          if(file.exists()){   
  46. //              Log.i("tag", "The file has already exists.");   
  47. //              return;   
  48. //          }   
  49.             try {   
  50.                 FileOutputStream fos = new FileOutputStream(file);   
  51.                 byte[] b = new byte[2048];   
  52.                 int j = 0;   
  53.                 while ((j = input.read(b)) != -1) {   
  54.                     fos.write(b, 0, j);   
  55.                 }   
  56.                 fos.flush();   
  57.                 fos.close();   
  58.             } catch (FileNotFoundException e) {   
  59.                 // TODO Auto-generated catch block   
  60.                 e.printStackTrace();   
  61.             } catch (IOException e) {   
  62.                 // TODO Auto-generated catch block   
  63.                 e.printStackTrace();   
  64.             }   
  65.         }else{   
  66.             Log.i("tag""NO SDCard.");   
  67.         }   
  68.     }   
  69.        
  70.     private String getMIMEType(File f){      
  71.       String type="";     
  72.       String fName=f.getName();     
  73.       /* 取得扩展名 */     
  74.       String end=fName.substring(fName.lastIndexOf(".")+1,fName.length()).toLowerCase();   
  75.          
  76.       /* 依扩展名的类型决定MimeType */  
  77.       if(end.equals("pdf")){   
  78.           type = "application/pdf";//   
  79.       }   
  80.       else if(end.equals("m4a")||end.equals("mp3")||end.equals("mid")||     
  81.       end.equals("xmf")||end.equals("ogg")||end.equals("wav")){     
  82.         type = "audio/*";      
  83.       }     
  84.       else if(end.equals("3gp")||end.equals("mp4")){     
  85.         type = "video/*";     
  86.       }     
  87.       else if(end.equals("jpg")||end.equals("gif")||end.equals("png")||     
  88.       end.equals("jpeg")||end.equals("bmp")){     
  89.         type = "image/*";     
  90.       }     
  91.       else if(end.equals("apk")){      
  92.         /* android.permission.INSTALL_PACKAGES */      
  93.         type = "application/vnd.android.package-archive";    
  94.       }   
  95. //      else if(end.equals("pptx")||end.equals("ppt")){   
  96. //        type = "application/vnd.ms-powerpoint";    
  97. //      }else if(end.equals("docx")||end.equals("doc")){   
  98. //        type = "application/vnd.ms-word";   
  99. //      }else if(end.equals("xlsx")||end.equals("xls")){   
  100. //        type = "application/vnd.ms-excel";   
  101. //      }   
  102.       else{   
  103. //        /*如果无法直接打开,就跳出软件列表给用户选择 */     
  104.         type="*/*";   
  105.       }   
  106.       return type;   
  107.     }   

安卓使用WebView下载文件,安卓实现软件升级功能

标签:安卓   webview   线程   安卓更新功能   

原文地址:http://blog.csdn.net/kan1kan5/article/details/40124335

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