4.8 抽象接口， 回调函数： 短信备份

1.创建读取短信的一个工具类，读取系统短信序列化到SDcard下的xml文件下

2.smsUtils提供一个接口，接口内提供两个回调函数, 将接口作为参数传给工具类

3.在activity中调用dao层内的方法，重写借口内的回调函数，得到短信的总数和序列化短信的条数

 

 

 

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1.创建读取短信的一个工具类，读取系统短信序列化到SDcard下的xml文件下

2.smsUtils提供一个接口，接口内提供两个回调函数, 将接口作为参数传给工具类

/**

 * 备份短信工具类

 * @author Administrator

 *

 */

public class SmsUtils {

      

      

      /**

       * 得到总共需要 备份多少条短信的条数,和当前备份了多少条短信的条数的接口

       * @author Administrator

       *

       */

      public interface  BackupCallback{

            

             /**

             * 在备份短信之前调用的方法

             * @param total 一共有多少个短信需要备份

             */

             public void beforeBackup( int total);    //把total传给调用类

            

             /**

             * 在短信备份的过程中调用的方法

             * @param process 当前已经备份了多少条的数据

             */

             public void onBackupProcess( int process);    //把process传给调用类

            

            

      }

      

      

      

      

      

      

      private static final String TAG = "SmsUtils";

      public  static void  backupSms(Context context,String path,BackupCallback  callback) throws Exception{

            

             //读取系统短信序列化到 sd卡中的xml文件上

            XmlSerializer serializer = Xml. newSerializer();

            

            File file= new File(path);

            FileOutputStream  fos= new FileOutputStream(file);

            serializer.setOutput(fos, "UTF-8");

            

             //创建内容解析这读取系统短信内容

              ContentResolver resolver = context.getContentResolver();

              Cursor cursor = resolver.query(Uri.parse("content://sms/"), new String[]{"address","date" ,"type" ,"body" }, null, null, null);

              int total = cursor.getColumnCount();   //得到数据库有多少条数据

              Log. i(TAG, "总共有" +total+"条短信" );

              callback.beforeBackup(total); //总共需要备份多少条短信

            

             

              //系列化系统短信到 xml文件上

              serializer.startDocument( "UTF-8", true);

              serializer.startTag( null, "smss");

             

              int process=0;

              while(cursor.moveToNext()){

                    serializer.startTag( null, "sms");

                   

                          serializer.startTag( null, "address");

                          serializer.text(cursor.getString(0));

                          serializer.endTag( null, "address");

                         

                         

                          serializer.startTag( null, "date");

                          serializer.text(cursor.getString(1));

                          serializer.endTag( null, "date");

                         

                         

                          serializer.startTag( null, "type");

                          serializer.text(cursor.getString(2));

                          serializer.endTag( null, "type");

                         

                         

                          serializer.startTag( null, "body");

                          serializer.text(cursor.getString(3));

                          serializer.endTag( null, "body");

                   

                   

                    serializer.endTag( null, "sms");

                    fos.flush();

                   

                    process++;

                    callback.onBackupProcess(process);   //当前备份了多少条数据

              }

              serializer.endTag( null, "smss");

              serializer.endDocument();

             

              //关闭资源

              cursor.close();

              fos.close();

             

      }

      

      

      

      

}

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3.在activity中调用dao层内的方法，重写借口内的回调函数，得到短信的总数和序列化短信的条数

/**

 * 短信的备份

 * @param v

 */

private ProgressDialog pd ;  //声明进度条对话框

private ProgressBar  pb_progress ;

public void backupSms(View v){

      Log.i(TAG , "备份短信......." );

      

   //获取并判断手机的SD卡状态

    String state = Environment. getExternalStorageState();

     if(!Environment. MEDIA_MOUNTED.equals(state)){

          Toast. makeText(getApplicationContext(), "SD卡不存在", 0).show();

           return;

      }

    

        //创建进度条对话框

        pd = new ProgressDialog( this);

             pd.setTitle( "提醒:");

             pd.setMessage( "正在备份短信" );

             pd.setProgressStyle(ProgressDialog. STYLE_HORIZONTAL);

             pd.show();

        //找到进度条控件

             pb_progress=(ProgressBar) findViewById(R.id.pb_progress);

      

      

     //在子线程中进行耗时操作

      new Thread(){

             public void run() {

                  Log. i(TAG, "备份短信" );

                  

                   //在SD卡下创建xml文件

                   File file= new File(Environment.getExternalStorageDirectory(), "sms.xml");

                  

                   //调用短信备份工具类

                   try {

                        

                        SmsUtils. backupSms(getApplicationContext(), file.getAbsolutePath(),new BackupCallback(){

                               @Override

                               public void beforeBackup( int total) {

                                    

                                     //进度条最大值

                                     pd.setMax(total); 

                                     pb_progress.setMax(total);

                              }

                               @Override

                               public void onBackupProcess( int process) {

                                     //进度条进度

                                     pd.setProgress(process);

                                     pb_progress.setProgress(process);

                              }

                              

                              

                              

                        });

                        ToastUtils. showToastInThread(AtoolsActivity.this, "备份成功");

                         pd.dismiss(); //关闭进度条对话框

                        

                  } catch (Exception e) {

                        e.printStackTrace();

                        ToastUtils. showToastInThread(AtoolsActivity.this, "备份失败");

                  }

                  

            }

            

      }.start();

      

      

      

}