RecyclerView+OkHttp展示网络数据

做项目涉及到联网肯定是需要展示网络数据的，RecyclerView+Okhttp展示网络数据虽然很基础很简单，但想想还是写出来让初学者了解一下

1、首先先导入需要用到的依赖包

//recyclerview用到的依賴包
    compile 'com.android.support:recyclerview-v7:25.1.1'
    //网络请求依赖包
    compile 'net.qiujuer.common:okhttp:3.0.0'

2、在布局文件里面设置RecyclerView控件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.example.administrator.okhttpdemo2.activity.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </android.support.v7.widget.RecyclerView>

</LinearLayout>

3、写一个item布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/texts"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:background="#f0f"
        android:gravity="center"
        android:textSize="20sp" />

</LinearLayout>

然后开始我们的代码工作

4、写需要用到的Bean（如果需要请求的数据多，需要什么数据就添加什么数据，不需要的可以不写，为了方便我只请求了一个数据条）

package com.example.administrator.okhttpdemo2.bean;

import java.util.List;

/**
 * Created by Administrator on 2017/5/25.
 */

public class Bean {
    private int code;
    private List<Data> data;
    private String msg;

    public Bean(int code, List<Data> data, String msg) {
        this.code = code;
        this.data = data;
        this.msg = msg;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public List<Data> getData() {
        return data;
    }

    public void setData(List<Data> data) {
        this.data = data;
    }

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    @Override
    public String toString() {
        return "Bean{" +
                "code=" + code +
                ", data=" + data +
                ", msg='" + msg + '\'' +
                '}';
    }

    public class Data {
        private int id;
        private String efficacy;
        private String goods_img;

        public Data(int id, String efficacy, String goods_img) {
            this.id = id;
            this.efficacy = efficacy;
            this.goods_img = goods_img;
        }

        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public String getEfficacy() {
            return efficacy;
        }

        public void setEfficacy(String efficacy) {
            this.efficacy = efficacy;
        }

        public String getGoods_img() {
            return goods_img;
        }

        public void setGoods_img(String goods_img) {
            this.goods_img = goods_img;
        }

        @Override
        public String toString() {
            return "Data{" +
                    "id=" + id +
                    ", efficacy='" + efficacy + '\'' +
                    ", goods_img='" + goods_img + '\'' +
                    '}';
        }
    }
}

5、设置我们的适配器（就是RecyclerView的适配器，和普通的展示String数据不一样，不过也相差不多，看代码）

package com.example.administrator.okhttpdemo2.adapter;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.example.administrator.okhttpdemo2.R;
import com.example.administrator.okhttpdemo2.bean.Bean;

/**
 * Created by Administrator on 2017/5/25.
 */

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyHolder> {
    private Context context;
    private Bean bean;

    public MyAdapter(Context context, Bean bean) {
        this.context = context;
        this.bean = bean;
    }

    @Override
    public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        MyHolder holder = new MyHolder(LayoutInflater.from(context).inflate(R.layout.item, parent, false));
        return holder;
    }

    @Override
    public void onBindViewHolder(MyHolder holder, int position) {
        holder.texts.setText(bean.getData().get(position).getEfficacy());
    }

    @Override
    public int getItemCount() {
        return bean.getData().size();
    }


    class MyHolder extends RecyclerView.ViewHolder {

        TextView texts;

        public MyHolder(View itemView) {
            super(itemView);
            texts = (TextView) itemView.findViewById(R.id.texts);
        }
    }
}

6、添加已经封装好的OkHttp工具类，（不要嫌多，工具类直接粘过去用就行）

package com.example.administrator.okhttpdemo2.okhttp;

import android.os.Handler;
import android.os.Looper;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;

import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.FormBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

/**
 * Created by fan on 2016/11/9.
 */

public class OkHttp {

    /**
     * 静态实例
     */
    private static OkHttp sOkHttpManager;

    /**
     * okhttpclient实例
     */
    private OkHttpClient mClient;

    /**
     * 因为我们请求数据一般都是子线程中请求，在这里我们使用了handler
     */
    private Handler mHandler;

    /**
     * 构造方法
     */
    private OkHttp() {

        mClient = new OkHttpClient();

        /**
         * 在这里直接设置连接超时.读取超时，写入超时
         */
        mClient.newBuilder().connectTimeout(10, TimeUnit.SECONDS);
        mClient.newBuilder().readTimeout(10, TimeUnit.SECONDS);
        mClient.newBuilder().writeTimeout(10, TimeUnit.SECONDS);

        /**
         * 如果是用的3.0之前的版本  使用以下直接设置连接超时.读取超时，写入超时
         */

        //client.setConnectTimeout(10, TimeUnit.SECONDS);
        //client.setWriteTimeout(10, TimeUnit.SECONDS);
        //client.setReadTimeout(30, TimeUnit.SECONDS);


        /**
         * 初始化handler
         */
        mHandler = new Handler(Looper.getMainLooper());
    }


    /**
     * 单例模式  获取OkHttp实例
     *
     * @return
     */
    public static OkHttp getInstance() {

        if (sOkHttpManager == null) {
            sOkHttpManager = new OkHttp();
        }
        return sOkHttpManager;
    }

    //-------------------------同步的方式请求数据--------------------------

    /**
     * 对外提供的get方法,同步的方式
     *
     * @param url 传入的地址
     * @return
     */
    public static Response getSync(String url) {

        //通过获取到的实例来调用内部方法
        return sOkHttpManager.inner_getSync(url);
    }

    /**
     * GET方式请求的内部逻辑处理方式，同步的方式
     *
     * @param url
     * @return
     */
    private Response inner_getSync(String url) {
        Request request = new Request.Builder().url(url).build();
        Response response = null;
        try {
            //同步请求返回的是response对象
            response = mClient.newCall(request).execute();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return response;
    }

    /**
     * 对外提供的同步获取String的方法
     *
     * @param url
     * @return
     */
    public static String getSyncString(String url) {
        return sOkHttpManager.inner_getSyncString(url);
    }


    /**
     * 同步方法
     */
    private String inner_getSyncString(String url) {
        String result = null;
        try {
            /**
             * 把取得到的结果转为字符串，这里最好用string()
             */
            result = inner_getSync(url).body().string();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }

    //-------------------------异步的方式请求数据--------------------------
    public static void getAsync(String url, DataCallBack callBack) {
        getInstance().inner_getAsync(url, callBack);
    }

    /**
     * 内部逻辑请求的方法
     *
     * @param url
     * @param callBack
     * @return
     */
    private void inner_getAsync(String url, final DataCallBack callBack) {
        final Request request = new Request.Builder().url(url).build();

        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                deliverDataFailure(request, e, callBack);
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String result = null;
                try {
                    result = response.body().string();
                } catch (IOException e) {
                    deliverDataFailure(request, e, callBack);
                }
                deliverDataSuccess(result, callBack);
            }
        });
    }


    /**
     * 分发失败的时候调用
     *
     * @param request
     * @param e
     * @param callBack
     */
    private void deliverDataFailure(final Request request, final IOException e, final DataCallBack callBack) {
        /**
         * 在这里使用异步处理
         */
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                if (callBack != null) {
                    callBack.requestFailure(request, e);
                }
            }
        });
    }

    /**
     * 分发成功的时候调用
     *
     * @param result
     * @param callBack
     */
    private void deliverDataSuccess(final String result, final DataCallBack callBack) {
        /**
         * 在这里使用异步线程处理
         */
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                if (callBack != null) {
                    try {
                        callBack.requestSuccess(result);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }

    /**
     * 数据回调接口
     */
    public interface DataCallBack {
        void requestFailure(Request request, IOException e);

        void requestSuccess(String result) throws Exception;
    }

    //-------------------------提交表单--------------------------

    public static void postAsync(String url, Map<String, String> params, DataCallBack callBack) {
        getInstance().inner_postAsync(url, params, callBack);
    }

    private void inner_postAsync(String url, Map<String, String> params, final DataCallBack callBack) {

        RequestBody requestBody = null;
        if (params == null) {
            params = new HashMap<>();
        }

        /**
         * 如果是3.0之前版本的，构建表单数据是下面的一句
         */
        //FormEncodingBuilder builder = new FormEncodingBuilder();

        /**
         * 3.0之后版本
         */
        FormBody.Builder builder = new FormBody.Builder();

        /**
         * 在这对添加的参数进行遍历，map遍历有四种方式，如果想要了解的可以网上查找
         */
        for (Map.Entry<String, String> map : params.entrySet()) {
            String key = map.getKey().toString();
            String value = null;
            /**
             * 判断值是否是空的
             */
            if (map.getValue() == null) {
                value = "";
            } else {
                value = map.getValue();
            }
            /**
             * 把key和value添加到formbody中
             */
            builder.add(key, value);
        }
        requestBody = builder.build();
        //结果返回
        // 请求对象
        final Request request = new Request.Builder().url(url).post(requestBody).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                deliverDataFailure(request, e, callBack);
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                String result = response.body().string();
                deliverDataSuccess(result, callBack);
            }


        });
    }


    //-------------------------文件下载--------------------------
    public static void downloadAsync(String url, String desDir, DataCallBack callBack) {
        getInstance().inner_downloadAsync(url, desDir, callBack);
    }

    /**
     * 下载文件的内部逻辑处理类
     *
     * @param url      下载地址
     * @param desDir   目标地址
     * @param callBack
     */
    private void inner_downloadAsync(final String url, final String desDir, final DataCallBack callBack) {
        final Request request = new Request.Builder().url(url).build();
        mClient.newCall(request).enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {
                deliverDataFailure(request, e, callBack);
            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {

                /**
                 * 在这里进行文件的下载处理
                 */
                InputStream inputStream = null;
                FileOutputStream fileOutputStream = null;
                try {
                    //文件名和目标地址
                    File file = new File(desDir, getFileName(url));
                    //把请求回来的response对象装换为字节流
                    inputStream = response.body().byteStream();
                    fileOutputStream = new FileOutputStream(file);
                    int len = 0;
                    byte[] bytes = new byte[2048];
                    //循环读取数据
                    while ((len = inputStream.read(bytes)) != -1) {
                        fileOutputStream.write(bytes, 0, len);
                    }
                    //关闭文件输出流
                    fileOutputStream.flush();
                    //调用分发数据成功的方法
                    deliverDataSuccess(file.getAbsolutePath(), callBack);
                } catch (IOException e) {
                    //如果失败，调用此方法
                    deliverDataFailure(request, e, callBack);
                    e.printStackTrace();
                } finally {
                    if (inputStream != null) {
                        inputStream.close();
                    }
                    if (fileOutputStream != null) {
                        fileOutputStream.close();
                    }

                }
            }

        });
    }

    /**
     * 根据文件url获取文件的路径名字
     *
     * @param url
     * @return
     */
    private String getFileName(String url) {
        int separatorIndex = url.lastIndexOf("/");
        String path = (separatorIndex < 0) ? url : url.substring(separatorIndex + 1, url.length());
        return path;
    }


}

最后一步就是进行MainActivity里面的代码工作

package com.example.administrator.okhttpdemo2.activity;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;

import com.example.administrator.okhttpdemo2.R;
import com.example.administrator.okhttpdemo2.adapter.MyAdapter;
import com.example.administrator.okhttpdemo2.bean.Bean;
import com.example.administrator.okhttpdemo2.okhttp.OkHttp;
import com.google.gson.Gson;

import java.io.IOException;

import okhttp3.Request;

public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclrview;
    private Bean bean;
    private MyAdapter myAdapter;
    private String path = "http://m.yunifang.com/yunifang/mobile/goods/getall?random=39986&encode=2092d7eb33e8ea0a7a2113f2d9886c90&category_id=17";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setOkHttp();
    }

    public void setRecyclerView() {
        recyclrview = (RecyclerView) findViewById(R.id.recyclerview);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        recyclrview.setLayoutManager(linearLayoutManager);
        myAdapter = new MyAdapter(MainActivity.this, bean);
        recyclrview.setAdapter(myAdapter);
    }

    public void setOkHttp() {
        OkHttp.getAsync(path, new OkHttp.DataCallBack() {
            @Override
            public void requestFailure(Request request, IOException e) {

            }

            @Override
            public void requestSuccess(String result) throws Exception {
                Gson gson = new Gson();
                bean = gson.fromJson(result, Bean.class);
                setRecyclerView();
            }
        });
    }
}

别忘记了在Androidapplication.xml里面添加联网权限

    <uses-permission android:name="android.permission.INTERNET"></uses-permission>

完事，明白里面的过程其实很简单的，希望对有的人有所帮助

最后附上源码
http://download.youkuaiyun.com/detail/lanrenxiaowen/9852141