安卓学习之文件存储（笔记）

通过getSharedPreferences（“文件名”，权限）获取SharedPreferences；

SharedPreferences sp = getSharedPreferences(“info”,MODE_PRIVATE);
- 保存值：（通过sp获取edit，通过edit中的方法进行保存值）
Editor editor= sp.edit();
editor.putString(“uName”,uName); //uName在这里是从后台获取的用户名数据
editor.putString(“uPass”,uPass); //upass是从后台获取的密码数据
editor.commit();
- 取值：
String u =sp.getString(“uName”,”“);
String p =sp.getString(“uPass”,”“);

序列化

以短信为例：

public class CMS {    private String  form;    private String contentx;    private String time;    public String getForm() {        return form;    }    public void setForm(String form) {        this.form = form;    }    public String getContentx() {        return contentx;    }    public void setContentx(String contentx) {        this.contentx = contentx;    }    public String getTime() {        return time;    }    public void setTime(String time) {        this.time = time;    }    @Override    public String toString() {        return "CMS{" +                "form='" + form + '\'' +                ", contentx='" + contentx + '\'' +                ", time='" + time + '\'' +                '}';    }}

使用普通方法保存数据到xml：

    public void saveCMS(view v){       StringBuffer  sb= new StringBuffer();        sb.append("<?xml version=\"1.0\" encoding=\"utf-8\"?>");        sb.append("<smsList>");        for (int i=0;i<cmsList.size();i++){            CMS  cms=cmsList.get(i);            sb.append("<cms>");            sb.append("<form>");            sb.append(cms.getForm());            sb.append("</form>");            sb.append("<content>");            sb.append(cms.getContent());            sb.append("</content>");            sb.append("<time>");            sb.append(cms.getTime());            sb.append("</time>");            sb.append("</cms>");        }        sb.append("</smsList>");        String xml = sb.toString();        try{            FileOutputStream  fos =openFileOutput("cms.xml",MODE_PRIVATE);            fos.write(xml.getBytes());            fos.close();        }catch (Exception e){             e.printStackTrace();        }    }

使用序列化进行保存数据

 //xml序列化器    public  void saveCMSby(view v){      XmlSerializer serializer= Xml.newSerializer();        try{            serializer.setOutput(openFileOutput("cms.xml",MODE_PRIVATE),"utf-8");            serializer.startDocument("utf-8",true);            serializer.startTag(null,"scmlist");            for(CMS m:cmsList){                serializer.startTag(null,"cms");                serializer.startTag(null,"form");                serializer.text(m.getForm());                serializer.endTag(null,"form");                serializer.startTag(null,"content");                serializer.text(m.getContent());                serializer.endTag(null,"content");                serializer.startTag(null,"time");                serializer.text(m.getTime());                serializer.endTag(null,"time");                serializer.endTag(null,"cms");            }            serializer.endTag(null,"scmlist");            serializer.endDocument();        }catch (Exception e){            e.printStackTrace();        }    }

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解析xml文件

获取解析器：

public  void  parXml(View  view){        XmlPullParser pullParser=Xml.newPullParser();        List<CMS> cmsList=null;        CMS cms=null;        try {            pullParser.setInput(openFileInput("cms.xml"),"utf-8");            int  eventType=pullParser.getEventType();            while (eventType!=XmlPullParser.END_DOCUMENT){                switch (eventType){                    case XmlPullParser.START_TAG:                        if("cmslist".equals(pullParser.getName())) {                                cmsList=new ArrayList<>();                        }else if("cms".equals(pullParser.getName())){                            cms=new CMS();                        }else if("form".equals(pullParser.getName())){                            cms.setForm(pullParser.nextText());                        }else if("content".equals(pullParser.getName())){                            cms.setContent(pullParser.nextText());                        }else if("time".equals(pullParser.getName())){                            cms.setTime(pullParser.nextText());                        }                        break;                    case XmlPullParser.END_TAG:                        if("cms".equals(pullParser.getName())){                            cmsList.add(cms);                        }                        break;                }               eventType= pullParser.next();            }        }catch (Exception e){            e.printStackTrace();        }    }