练习 一

//MainActivity代码

package com.example.zhoukaoyi;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;
import com.example.zhoukaoyi.adapter.Rvadapter;
import com.example.zhoukaoyi.bean.Bean;
import com.example.zhoukaoyi.bean.Bh;
import com.example.zhoukaoyi.bean.Xiaobean;
import com.example.zhoukaoyi.gen.BhDao;
import com.example.zhoukaoyi.utils.DbHelper;
import org.greenrobot.eventbus.EventBus;
import org.greenrobot.eventbus.Subscribe;
import org.greenrobot.eventbus.ThreadMode;
import java.util.ArrayList;
import java.util.List;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
import retrofit2.Retrofit;
import retrofit2.converter.gson.GsonConverterFactory;

/**
 * Created by  o
 */

public class fragment1 extends Fragment {

    private ApiService service1;
    private Rvadapter adapters;
    RecyclerView rv;
    private List<Bh> list = new ArrayList<>();
    private BhDao xiaobeanDao;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        EventBus.getDefault().register(this);
        View view = inflater.inflate(R.layout.fragment1, container, false);
        rv=view.findViewById(R.id.rv);
        return view;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        //数据库
        xiaobeanDao = DbHelper.getInstance(getActivity()).getXiaobeanDao();
        LinearLayoutManager manager = new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false);
        rv.setLayoutManager(manager);
        adapters = new Rvadapter(getActivity(), list);
        rv.setAdapter(adapters);

        //判断网络
        int netype = WifeUtils.getInstance(getActivity()).getNetype();
        if (netype==-1){
            EventBus.getDefault().post("没网");
            getORMData();
        }else{//有网
            EventBus.getDefault().post("有网");
            getNetdata();
        }
    }

    @Subscribe(threadMode = ThreadMode.MAIN)
    public void  onMessageEvent(String event){
        Toast.makeText(getActivity(),event,Toast.LENGTH_SHORT).show();
    }

    public void getORMData(){
        //得到数据库数据
        List<Bh> bhs = xiaobeanDao.loadAll();
        //填装到展示的集合
        list.addAll(bhs);
        adapters.notifyDataSetChanged();
    }

    //网络请求
    public void getNetdata(){
        //获取接口地址
        Retrofit retrofit = new Retrofit.Builder()
                //自动Gson解析
                .addConverterFactory(GsonConverterFactory.create())
                .baseUrl("http://gank.io/")
                .build();
        //获取类类型对象
        service1 = retrofit.create(ApiService.class);
        //接口中的bean类
        Call<Bean<List<Xiaobean>>> call = service1.GroupList(10,1);
        call.enqueue(new Callback<Bean<List<Xiaobean>>>() {
            @Override
            public void onResponse(Call<Bean<List<Xiaobean>>> call, Response<Bean<List<Xiaobean>>> response) {
                //通过流的形式获取数据
                Bean<List<Xiaobean>> body = response.body();
                List<Xiaobean> results = body.getResults();

                //清空数据库
                xiaobeanDao.deleteAll();

                //实例化数据类型对象
                Bh bh = new Bh();
                for(int i=0;i<results.size();i++){
                    bh.setId(null);
                    bh.setH(results.get(i).getCreatedAt());
                    bh.setWb(results.get(i).getDesc());
                    list.add(new Bh(null,results.get(i).getDesc(),results.get(i).getCreatedAt()));
                    //添加到数据库
                    xiaobeanDao.insert(bh);
                }

                //刷新适配器
                adapters.notifyDataSetChanged();
            }

            @Override
            public void onFailure(Call<Bean<List<Xiaobean>>> call, Throwable t) {
            }
        });
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        EventBus.getDefault().unregister(this);
    }
}

/////////////////////////////////////////////获取路径需要创建接口

package com.example.zhoukaoyi;
import com.example.zhoukaoyi.bean.Bean;
import com.example.zhoukaoyi.bean.Xiaobean;
import java.util.List;
import retrofit2.Call;
import retrofit2.http.GET;
import retrofit2.http.Path;

/**
 * Created by
 */

public interface ApiService {
    //参数地址
    @GET("api/data/Android/{id1}/{id2}")
    Call<Bean<List<Xiaobean>>> GroupList(@Path("id1") int id1,@Path("id2") int id2);

      //参数拼接
//    @GET("api/data/Android")
//    Call<Bean<List<Xiaobean>>> GroupList(@Query("uid") int uid,@Query("name") String name);
}

//////////////////////////////////适配器

package com.example.zhoukaoyi.adapter;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import com.example.zhoukaoyi.R;
import com.example.zhoukaoyi.bean.Bh;
import com.facebook.drawee.view.SimpleDraweeView;

import java.util.List;

/**
 * Created
 */


//适配器
public class Rvadapter extends RecyclerView.Adapter<Rvadapter.ViewHolder>{
    private Context context;
    private List<Bh> list;

    public Rvadapter(Context context, List<Bh> list) {
        this.context = context;
        this.list = list;
    }
    @Override
    public Rvadapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = View.inflate(context, R.layout.rv_fragment, null);
        ViewHolder holder = new ViewHolder(view);
        return holder;
    }

    @Override
    public void onBindViewHolder(Rvadapter.ViewHolder holder, int position) {
        holder.title.setText(list.get(position).getWb());
        holder.type.setText(list.get(position).getH());
        holder.img.setImageURI("http://www.cndog.net/tpb/2013-12/14/14970-6031.jpg");
    }

    @Override
    public int getItemCount() {
        return list.size();
    }
    class ViewHolder extends RecyclerView.ViewHolder{

        private final SimpleDraweeView img;
        private final TextView title;
        private final TextView type;

        public ViewHolder(View itemView) {
            super(itemView);
            img =itemView.findViewById(R.id.img);
            title =itemView.findViewById(R.id.title);
            type =itemView.findViewById(R.id.type);
        }
    }
}
/////////////////////////////////数据库的封装类工具类
package com.example.zhoukaoyi.utils;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import com.example.zhoukaoyi.gen.BhDao;
import com.example.zhoukaoyi.gen.DaoMaster;
import com.example.zhoukaoyi.gen.DaoSession;

/**
 * Created by 
 */

public class DbHelper {
    private static  volatile DbHelper instance;
    private final DaoSession daoSession;
    private final DaoMaster daoMaster;

    private DbHelper(Context context){
        DaoMaster.DevOpenHelper xiaokai = new DaoMaster.DevOpenHelper(context, "zhoukaoyi", null);
        SQLiteDatabase writableDatabase = xiaokai.getWritableDatabase();
        daoMaster = new DaoMaster(writableDatabase);
        daoSession = daoMaster.newSession();
    }
    public static DbHelper getInstance(Context context){
        if (instance==null){
            synchronized (DbHelper.class){
                if (null==instance){
                    instance=new DbHelper(context);
                }
            }
        }
        return instance;
    }

    //将daoSessionDao返回
    public BhDao getXiaobeanDao() {
        return daoSession.getBhDao();
    }
}

///////////////////////////////////////网络判断工具类

package com.example.zhoukaoyi;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

/**
 * Created by
 */

//判断网络
public class WifeUtils {
        private static volatile WifeUtils instance;
        private Context context;
        private WifeUtils(Context context) {
            this.context = context;
        }
        public static WifeUtils getInstance(Context context) {
            if (instance == null) {
                synchronized (WifeUtils.class) {
                    if (instance == null) {
                        instance = new WifeUtils(context);
                    }
                }
            }
            return instance;
        }

        public int getNetype() {
            int netType = -1;
            ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
            //无网络
            if (networkInfo == null) {
                return netType;
            }
            int nType = networkInfo.getType();
            //手机网络
            if (nType == ConnectivityManager.TYPE_MOBILE) {
                netType = 2;
            } else if (nType == ConnectivityManager.TYPE_WIFI) {//wifi网络
                netType = 1;
            }
            //返回
            return netType;
        }
}

//////////////////////////////////泛型Bean类

package com.example.zhoukaoyi.bean;

/**
 * Created by 
 */

public class Bean<T> {

    private boolean error;
    private T results;

    public boolean isError() {
        return error;
    }

    public void setError(boolean error) {
        this.error = error;
    }

    public T getResults() {
        return results;
    }

    public void setResults(T results) {
        this.results = results;
    }
}

/////////////////////////////////自己创建的类  需要的属性

package com.example.zhoukaoyi.bean;
import org.greenrobot.greendao.annotation.Entity;
import org.greenrobot.greendao.annotation.Id;
import org.greenrobot.greendao.annotation.Generated;

/**
 * Cr.
 */

@Entity
public class Bh {
    @Id
    private Long id;
    private String Wb;
    private String h;
    @Generated(hash = 329677494)
    public Bh(Long id, String Wb, String h) {
        this.id = id;
        this.Wb = Wb;
        this.h = h;
    }
    @Generated(hash = 1817500822)
    public Bh() {
    }
    public Long getId() {
        return this.id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getWb() {
        return this.Wb;
    }
    public void setWb(String Wb) {
        this.Wb = Wb;
    }
    public String getH() {
        return this.h;
    }
    public void setH(String h) {
        this.h = h;
    }
}