Android系统的五种数据存储形式（二）

package com.example.contentprovider;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.ArrayList;
import java.util.List;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlSerializer;

import android.app.Activity;
import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.util.Log;
import android.util.Xml;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
/**
 * 短信的备份和还原
 * 添加写短信和读短信的权限
 *  <uses-permission android:name="android.permission.READ_SMS"/>
    <uses-permission android:name="android.permission.WRITE_SMS"/>
 * @author Huang
 */
  public class MainActivity extends Activity {
    private static final String TAG = "MainActivity";
	private ListView lv;
    private List<Person> mlist;
    private Myadpter adapter;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		lv = (ListView) findViewById(R.id.lv);
		datafresh();
	}
	//数据刷新，一般用到ListView时最好记得刷新数据否则不显示
	public void datafresh(){
		mlist = getList();
		if(adapter == null){
			adapter = new Myadpter();
		}else {
			adapter.notifyDataSetChanged();
		}
	}
	//用ListView显示短信内容
	public class Myadpter extends BaseAdapter{
		public int getCount() {
			// TODO Auto-generated method stub
			return mlist.size();
		}
		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return null;
		}
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return 0;
		}
		public View getView(int position, View convertView, ViewGroup parent) {
			TextView tv = new TextView(MainActivity.this);
			tv.setText(mlist.get(position).toString());
			return tv;
		}
	}
    //短信备份	
    public void bankup(View view){
    	ContentResolver resolver = getContentResolver();
    	Uri uri = Uri.parse("content://sms");
    	Cursor cursor = resolver.query(uri, new String[]{"address","body","type","date"}, null, null, null);
    	while(cursor.moveToNext()){
    		String address = cursor.getString(0);
    		String body = cursor.getString(1);
    		String type = cursor.getString(2);
    		String date = cursor.getString(3);
    		//序列化，把短信以Xml文件的形式存储
    		XmlSerializer serializer = Xml.newSerializer();
    		File file = new File(getFilesDir(),"info.xml");
    		try {
				FileOutputStream fos = new FileOutputStream(file);
				serializer.setOutput(fos, "utf-8");
				serializer.startDocument("utf-8", true);
				serializer.startTag(null, "person");
				
                serializer.startTag(null, "address");
                serializer.text(address);
                serializer.endTag(null, "address");
                
                serializer.startTag(null, "body");
                serializer.text(body);
                serializer.endTag(null, "body");
                
                serializer.startTag(null, "type");
                serializer.text(type);
                serializer.endTag(null, "type");
                
                serializer.startTag(null, "date");
                serializer.text(date);
                serializer.endTag(null, "date");
                
				serializer.endTag(null, "person");
				serializer.endDocument();
				fos.close();
//				Toast.makeText(this, "数据保存成功", 0).show();
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
    	}
    }

    public void restore(View view){
    	datafresh();
    	lv.setAdapter(adapter);
    }
    //利用Xml解析得到短信内容
    private List<Person> getList() {
		ContentResolver resolver = getContentResolver();
    	List<Person> list = new ArrayList();//创建一个Person类存储标签内容
    	Person p = new Person();
    	File file = new File(getFilesDir(),"info.xml");
    	XmlPullParser pullParser = Xml.newPullParser();
    	try {
    		FileInputStream fis = new FileInputStream(file);
			pullParser.setInput(fis, "utf-8");
			int mtype = pullParser.getEventType();
			while(mtype != XmlPullParser.END_DOCUMENT){
				String name = pullParser.getName();
				switch (mtype){
				case XmlPullParser.START_TAG:
					if("address".equals(name)){
						String address = pullParser.nextText();
						p.setAddress(address);
					}else if("body".equals(name)){
						String body = pullParser.nextText();
						p.setBody(body);
					}else if("type".equals(name)){
						String type = pullParser.nextText();
						p.setType(type);
					}else if("date".equals(name)){
						String date = pullParser.nextText();
						p.setDate(date);
					}
					break;
				case XmlPullParser.END_TAG:
					if("person".equals(name)){
						list.add(p);
					}
					break;
				}
				mtype = pullParser.next();
			}
            Log.i(TAG, list.toString());
            return list;
		} catch (Exception e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
	}
}