保存到数据库(无网络可查看)

创建数据库

public class MyHelper extends SQLiteOpenHelper{

    public MyHelper(Context context) {
        super(context, "yuekao.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        sqLiteDatabase.execSQL("create table Yk(id integer primary key autoincrement,json text)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {

    }
}

调用数据库

public class MyManager {
    Context context;
    SQLiteDatabase db;

    public MyManager(Context context) {
        this.context = context;
        MyHelper helper = new MyHelper(context);
        db = helper.getWritableDatabase();
    }

    public void insert(String json){
        ContentValues values = new ContentValues();
        values.put("json",json);
        db.insert("Yk",null,values);
    }

    public String select(){
        String json = "";
        Cursor cursor =  db.query("Yk",null,null,null,null,null,null);
        while(cursor.moveToNext()){
            json = cursor.getString(cursor.getColumnIndex("json"));
        }
        return json;

    }
}

在Mainactivity中调用数据库

Mymanager myManager = new MyManager(getActivity());

 String json = myManager.select();
        //没网，从数据库中获取
        if(json!=null&&!json.equals("")){
            MyBean myBean = new Gson().fromJson(json, MyBean.class);
            if(myBean!=null){
                List<MyBean.ResultBean.DataBean> data = myBean.getResult().getData();
                xListView.setAdapter(new MyAdapter(data,getActivity()));
            }

        }else{
            //有网
            initData(true);
        }