手动拼接字符串

 File file = new File(getFilesDir(), "xaioer.xml");
        
        try {
            OutputStream os = new FileOutputStream(file);
            
            
            StringBuilder build = new StringBuilder();
            
            build.append("<?xml version='1.0' encoding='utf-8' ?>");
            build.append("<student>");
            build.append("<name>");
            build.append("xiaoer");
            build.append("</name>");
            
            build.append("</student>");
            os.write(build.toString().getBytes());
            os.close();
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

XmlSerializer

 try {
            File f = new File(getFilesDir(), "xiaoer.xml");
            OutputStream os = new FileOutputStream(f);
            
            XmlSerializer s = Xml.newSerializer();
            s.setOutput(os, "utf-8");
            s.startDocument("utf-8", true);
            s.startTag(null, "student");
            s.text("haha");
            s.endTag(null, "student");
            s.endDocument();
            
            
        
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        

使用的是Xmlpullparser

try {
        
      //创建工厂
    XmlPullParserFactory fac = XmlPullParserFactory.newInstance();
      //设置支持名称空间的解析
            fac.setNamespaceAware(true);
            
            XmlPullParser pull = fac.newPullParser();
            
            pull.setInput(new FileReader(new File(getFilesDir(),"xiaoer.xml")));
            
            StringBuilder b = new StringBuilder();
            // 查看类型 事件驱动的
            int type = pull.getEventType();
            
  //如果不是查询到了  pull.END_DOCUMENT 文档的结束 那么将指针指向下一个type = pull.next();
//pull.getText()得到对应标签中的文本 pull.getName();得到标签的名字
            while(type!= pull.END_DOCUMENT) {
                
                if ( type == pull.TEXT ) {
                    b.append(pull.getText());
                }
                
                type = pull.next();
                
            }
            
            Log.e("xiaoer", "sb");
            Log.e("xiaoer", b.toString());
            
        } catch (Exception e) {
            // TODO Auto-generated catch block
        
            Log.e("xiaoer",e.getMessage());
        }