Android之短信备份

写短信备份的简单应用主要是为了使用xml的序列化，下面是读取短信数据库中短信信息，并将其转化成xml文件

                                int index = 0;
				Uri uri = Uri.parse("content://sms");
				// 读取短信
				Cursor cursor = getContentResolver().query(uri, new String[] { "address", "date", "type", "body" },
						null, null, null);
				// 获取SD卡路径
				String path = Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator
						+ "sms_backup.xml";
				// 备份短信的总数
				int count = cursor.getCount();
				progressDialog.setMax(count);
				if (count > 0) {
					try {
						File file = new File(path);
						FileOutputStream fos = new FileOutputStream(file);
						// 序列化数据库中读取的数据，放到xml中
						XmlSerializer serializer = Xml.newSerializer();
						serializer.setOutput(fos, "utf-8");
						serializer.startDocument("utf-8", true);// 独立的xml,开始结束配套
						serializer.startTag(null, "smss"); // 第二个参数是开始节点
						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");

							index = index + 1;
							progressDialog.setProgress(index);
							if (index == cursor.getCount()) {
								progressDialog.dismiss();
							}
						}
						serializer.endTag(null, "smss");
						serializer.endDocument();
					} catch (Exception e) {
						e.printStackTrace();
					}
				} else {
					runOnUiThread(new Runnable() {
						public void run() {
							Toast.makeText(getApplicationContext(), "没有短信可备份", 0).show();
						}
					});
				}

			};