判断网络状态 数据库 还是网络

首先先创建5个fragment
此步骤省略
创建bean 类
此步骤省略
创建v层
public interface Iview {
    void showView(List list);
    void show(List list);
}
创建m层
接口回调
public interface Imodel {
    void getData(Observer observer);
}
model层
public class ImodelBack implements Imodel{
    @Override
    public void getData(Observer observer) {
        OkHttpClient OkClient = new OkHttpClient.Builder().build();
        //使用Retrofit进行设置
        Retrofit retrofit = new Retrofit.Builder()
                //添加OkHttpClient
                .client(OkClient)
                //添加接口头部
                .baseUrl(BaseUtils.BASE_URL)
                //设置解析方式
                .addConverterFactory(GsonConverterFactory.create())
                //添加支持RxJAva
                .addCallAdapterFactory(RxJavaCallAdapterFactory.create()).build();
        URLUtils urlUtils = retrofit.create(URLUtils.class);
        //得到被观察者
        urlUtils.getObservable()
                //设置观察者在主线程
                .observeOn(AndroidSchedulers.mainThread())
                //设置被观察者在子线程
                .subscribeOn(Schedulers.io())
                //订阅观察者
                .subscribe(observer);
    }
p层
public class Mypresenter {
    Iview iview;
    ImodelBack imodelBack;
    MyUserDao dao;
    Context context;

    public Mypresenter(Iview iview,Context context) {
        this.iview = iview;
        imodelBack=new ImodelBack();
        this.context=context;

    }

    public void setData(boolean state){
        dao=new MyUserDao(context);
        if(!state){
           // Toast.makeText(context, "1111111", Toast.LENGTH_SHORT).show();
            //zoushujuku
            List been = dao.queryUserList();
            //Toast.makeText(context, "22222"+been.size(), Toast.LENGTH_SHORT).show();


              //  Toast.makeText(context, "33333", Toast.LENGTH_SHORT).show();
                iview.show(been);

        }else{
            //Toast.makeText(context, "44444", Toast.LENGTH_SHORT).show();

        imodelBack.getData(new Observer() {
            @Override
            public void onCompleted() {

            }

            @Override
            public void onError(Throwable e) {
                Log.i("======", "onError: "+e);
            }

            @Override
            public void onNext(User user) {
                Log.i("=======", "onNext: "+user.toString());
                List listBeen=user.getData().getActivityInfo().getActivityInfoList();
                iview.showView(listBeen);
                dao.deleteAll();
                List list = user.getData().getActivityInfo().getActivityInfoList();
                for (int i = 0; i < list.size(); i++) {
                    Bean bean = new Bean();
                    bean.setEndtime(list.get(i).getEndtime());
                    dao.insertUser(bean);

                }
            }
      });

        }
    }
}
}
util
public class BaseUtils {
    public static final String BASE_URL = "http://m.yunifang.com/";
}
public interface URLUtils {
    @GET("yunifang/mobile/home")
    Observable getObservable();
}
主页面
public class MainActivity extends AppCompatActivity {

    @BindView(R.id.vp)
    ViewPager vp;
    @BindView(R.id.rg)
    RadioGroup rg;
    List list;
    private One one;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        initData();
        boolean connectedByState = NetWorkUtils.isConnectedByState(this);
        Log.i("---222---", "onCreate: ");
        if(connectedByState){
            Log.i("----", "showView: ");
            Toast.makeText(this,"网络已连接",Toast.LENGTH_LONG).show();
            //EventBus.getDefault().postSticky(connectedByState);

        }else{
            Toast.makeText(this,"无网络连接",Toast.LENGTH_LONG).show();
            Log.i("--1111---", "showView: ");
        }


        MypagerAdpter madpter=new MypagerAdpter(getSupportFragmentManager());
        vp.setAdapter(madpter);
        one.getState(connectedByState);
        rg.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup radioGroup, @IdRes int i) {
                switch (i)
                {
                    case R.id.rb1:
                        vp.setCurrentItem(0);
                        break;
                    case R.id.rb2:
                        vp.setCurrentItem(1);
                        break;
                    case R.id.rb3:
                        vp.setCurrentItem(2);
                        break;
                    case R.id.rb4:
                        vp.setCurrentItem(3);
                        break;
                    case R.id.rb5:
                        vp.setCurrentItem(4);
                        break;
                }
            }
        });
        vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                switch (position)
                {
                    case 0:
                        rg.check(R.id.rb1);
                        break;
                    case 1:
                        rg.check(R.id.rb2);
                        break;
                    case 2:
                        rg.check(R.id.rb3);
                        break;
                    case 3:
                        rg.check(R.id.rb4);
                        break;
                    case 4:
                        rg.check(R.id.rb5);
                        break;
                }

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

    }

    private void initData() {
        list=new ArrayList();
        one = new One();
        list.add(one);
        list.add(new Two());
        list.add(new Three());
        list.add(new Four());
        list.add(new Fieve());
    }
    class MypagerAdpter extends FragmentPagerAdapter{

        public MypagerAdpter(FragmentManager fm) {
            super(fm);
        }

        @Override
        public Fragment getItem(int position) {
            return list.get(position);
        }

        @Override
        public int getCount() {
            return list.size();
        }
    }
}
fragmrnt
public class One extends Fragment implements Iview{
    RecyclerView rv;
    Mypresenter pp;
    private boolean state1;
    boolean flag;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = View.inflate(getActivity(), R.layout.one, null);
       // EventBus.getDefault().register(getActivity());
        rv=view.findViewById(R.id.rv);
        initData();
        return view;
    }

    @Override
    public void onResume() {
        super.onResume();
        pp=new Mypresenter(this,getActivity());
        pp.setData(flag);
    }


    private void initData() {
        LinearLayoutManager lin=new LinearLayoutManager(getActivity());
        rv.setLayoutManager(lin);
    }


    @Override
    public void showView(List listBeen) {

        rv.setAdapter(new Myadpter(listBeen,getActivity()));
    }

    @Override
    public void show(List list) {
  rv.setAdapter(new Myadpter_noneNet(list,getActivity()));


    }



    public void getState(boolean type){
        this.flag=type;

    }
}