android（16）（短信的备份，xml的序列化）

实体（entities）类：
public class SmsInfo {

    private int id;
    private String address;
    private long date;
    private int type;
    private String body;
    public SmsInfo(int id, String address, long date, int type, String body) {
        super();
        this.id = id;
        this.address = address;
        this.date = date;
        this.type = type;
        this.body = body;
    }
    @Override
    public String toString() {
        return "SmsInfo [id=" + id + ", address=" + address + ", date=" + date
                + ", type=" + type + ", body=" + body + "]";
    }
    public SmsInfo() {
        super();
        // TODO Auto-generated constructor stub
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public long getDate() {
        return date;
    }
    public void setDate(long date) {
        this.date = date;
    }
    public int getType() {
        return type;
    }
    public void setType(int type) {
        this.type = type;
    }
    public String getBody() {
        return body;
    }
    public void setBody(String body) {
        this.body = body;
    }
public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }

    /**
     * 备份短信
     * @param v
     */
    public void backupSms(View v) {
        // 1. 查出所有的短信
        Uri uri = Uri.parse("content://sms/");

        ContentResolver resolver = getContentResolver();
        Cursor cursor = resolver.query(uri, new String[]{"_id", "address", "date", "type", "body"}, null, null, null);

        if(cursor != null && cursor.getCount() > 0) {
            List<SmsInfo> smsList = new ArrayList<SmsInfo>();
            SmsInfo sms;

            while(cursor.moveToNext()) {    // 控制游标结果集的指针向下移一位, 当到最后一位, 停止.返回false
                sms = new SmsInfo();
                sms.setId(cursor.getInt(0));    // 设置短信的id
                sms.setAddress(cursor.getString(1));    // 设置短信的号码
                sms.setDate(cursor.getLong(2)); // 设置短信的日期
                sms.setType(cursor.getInt(3));  // 设置短信的类型, 接收1还是发送2
                sms.setBody(cursor.getString(4)); // 设置短信的内容
                smsList.add(sms);
            }
            cursor.close();

            // 2. 序列化到本地
            writeToLocal(smsList);
        }
    }

    /**
     * 序列化到本地
     */
    private void writeToLocal(List<SmsInfo> smsList) {

        try {
            XmlSerializer serializer = Xml.newSerializer(); // 得到序列化对象
            // 指定输出位置
            FileOutputStream fos = new FileOutputStream("/mnt/sdcard/sms.xml");
            serializer.setOutput(fos, "utf-8");

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

            serializer.startTag(null, "smss");

            for (SmsInfo smsInfo : smsList) {
                serializer.startTag(null, "sms");
                serializer.attribute(null, "id", String.valueOf(smsInfo.getId()));

                // 写号码
                serializer.startTag(null, "address");
                serializer.text(smsInfo.getAddress());
                serializer.endTag(null, "address");

                // 写时间
                serializer.startTag(null, "date");
                serializer.text(String.valueOf(smsInfo.getDate()));
                serializer.endTag(null, "date");

                //写类型
                serializer.startTag(null, "type");
                serializer.text(String.valueOf(smsInfo.getType()));
                serializer.endTag(null, "type");

                // 写内容
                serializer.startTag(null, "body");
                serializer.text(smsInfo.getBody());
                serializer.endTag(null, "body");

                serializer.endTag(null, "sms");
            }

            serializer.endTag(null, "smss");

            serializer.endDocument();

            Toast.makeText(this, "备份成功", 0).show();
        } catch (Exception e) {
            Toast.makeText(this, "备份失败", 0).show();
            e.printStackTrace();
        }

    }