一、android下创建文件夹

	File sd=Environment.getExternalStorageDirectory();
        String path=sd.getPath()+"/notes";
        File file=new File(path);
        if(!file.exists())
           file.mkdir();
		

HttpClient httpClient = new DefaultHttpClient();
						HttpGet httpGet= new HttpGet("http://img3.3lian.com/2006/016/09/031.jpg");
						HttpResponse httpResponse = httpClient.execute(httpGet);
						if(httpResponse.getStatusLine().getStatusCode() == 200){
							 total_length = httpResponse.getEntity().getContentLength();
							 is = httpResponse.getEntity().getContent() ;     
					         File file = new File(Environment.getExternalStorageDirectory(), "aupdata.jpg");     
					         fos = new FileOutputStream(file);     
					         bis = new BufferedInputStream(is);     
					         byte[] buffer = new byte[1024];  
					         byte [] result_two = new byte [(int) total_length];
					         int len = 0;     
					        int total=0;  
					        while((len = bis.read(buffer)) > -1){
					        	System.arraycopy(buffer, 0, result_two, total, len);
					        	
					        	
					        	fos.write(buffer, 0, len);
					        	total = total + len ;
					        	
					   
					    	    }
					        }

三、android安装其他apk

                        Intent intent = new Intent();
			intent.setAction(Intent.ACTION_VIEW);
			File install_file = new File(Environment.getExternalStorageDirectory() , "MyWeb.apk");
			intent.setDataAndType(Uri.fromFile(install_file), "application/vnd.android.package-archive");
			startActivity(intent);