private String body;

private String number;

private int type;

private long id;

public static void backUpXml(File file, List<XmlInfo> smsInfos) throws Exception

    {

        //xml文件的序列号器  帮助生成一个xml文件

        FileOutputStream fos = new FileOutputStream(file);

        //获取到xml的序列号

        XmlSerializer serializer = Xml.newSerializer();

        //序列化初始化

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

        //创建xml

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

        serializer.startTag(null, "smss");

        for(XmlInfo info : smsInfos)

        {

            serializer.startTag(null, "sms");

            serializer.attribute(null, "id", String.valueOf(info.getId()));

            serializer.startTag(null, "body");

            serializer.attribute(null, "body", info.getBody());

            serializer.endTag(null, "body");

            serializer.startTag(null, "number");

            serializer.text(info.getNumber());

            serializer.endTag(null, "number");

            serializer.endTag(null, "sms");

        }

        serializer.endTag(null, "smss");

        serializer.endDocument();

        fos.flush();

        fos.close();

    }

List<XmlInfo> xmlinfo = new ArrayList<XmlInfo>();

        XmlInfo xml1 = new XmlInfo("aaaa","12345678912",1,1);

        XmlInfo xml2 = new XmlInfo("bbbb","21987654321",1,2);

        XmlInfo xml3 = new XmlInfo("cccc","12345678912",1,3);

        xmlinfo.add(xml1);

        xmlinfo.add(xml2);

        xmlinfo.add(xml3);

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

        //File file = new File(MainActivity.this.getFilesDir(),"back.xml");

        try {

            XmlManager.backUpXml(file, xmlinfo);

            Toast.makeText(this, "备份成功", 0).show();

        } catch (Exception e) {

            // TODO 自动生成的 catch 块

            e.printStackTrace();

            Toast.makeText(this, "备份失败", 0).show();

        }