安卓高级2 Volley框架的使用案例

初始化类:

MyApp.java

package qianfeng.com.day37_volley_pull.app;

import android.app.Application;

import com.android.volley.RequestQueue;

import com.android.volley.toolbox.Volley;

/**

 * Created by ${Mr.Zhao} on 2016/10/18.

 */

public class MyApp extends Application {

    //定义一个 请求队列

    private static RequestQueue requestQueue;

    @Override

    public void onCreate() {

        super.onCreate();

        // 初始化 请求队列

        requestQueue = Volley.newRequestQueue(this);

    }

    // 将消息队列返回

    public static RequestQueue getRequestQueue() {

        return requestQueue;

    }

}

零散并发下载字符数据

package qianfeng.com.day37_volley_pull;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.util.Log;

import android.view.View;

import com.android.volley.AuthFailureError;

import com.android.volley.Request;

import com.android.volley.Response;

import com.android.volley.VolleyError;

import com.android.volley.toolbox.JsonObjectRequest;

import com.android.volley.toolbox.StringRequest;

import org.json.JSONObject;

import java.util.HashMap;

import java.util.Map;

import qianfeng.com.day37_volley_pull.app.MyApp;

public class MainActivity extends AppCompatActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    public void onClick(View view) {

        switch (view.getId()) {

            case R.id.volley_get_bt:

                String path = "http://c.m.163.com/nc/article/list/T1370583240249/0-20.html";

                //   定义 一次请求

                /*

                1. 请求方式

                2.路径

                3.请求成功的回调监听

                4.请求错误的时候 回调监听

                 */

                StringRequest stringRequest = new StringRequest(Request.Method.GET, path, new Response.Listener<String>() {

                    @Override

                    public void onResponse(String response) {

                        Log.d("Mr.Zhao", "onResponse: " + response);

                    }

                }, new Response.ErrorListener() {

                    @Override

                    public void onErrorResponse(VolleyError error) {

                        Log.d("Mr.Zhao", "onErrorResponse: ");

                    }

                });

                //  将  这个请求 添加到  请求队列中！！！！！！

                MyApp.getRequestQueue().add(stringRequest);

                break;

            case R.id.volley_post_bt:

                String post_Path = "http://mrobot.pcauto.com.cn/v2/cms/channels/1?";

                StringRequest request = new StringRequest(Request.Method.POST, post_Path, new Response.Listener<String>() {

                    @Override

                    public void onResponse(String response) {

                        Log.d("Mr.Zhao", "onResponse: " + response);

                    }

                }, new Response.ErrorListener() {

                    @Override

                    public void onErrorResponse(VolleyError error) {

                        Log.d("Mr.Zhao", "onErrorResponse: " + error);

                    }

                }) {

                    @Override

                    protected Map<String, String> getParams() throws AuthFailureError {

                        Map<String, String> map = new HashMap<>();

                        map.put("pageNo", "1");

                        map.put("pageSize", "20");

                        map.put("serialIds", "2143,3404");

                        map.put("v", "4.0.0");

                        return map;

                    }

                };

                MyApp.getRequestQueue().add(request);

                break;

            case R.id.volley_object_bt:

                String object_path = "http://mrobot.pcauto.com.cn/v2/cms/channels/1?";

                JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST, object_path, null, new Response.Listener<JSONObject>() {

                    @Override

                    public void onResponse(JSONObject response) {

                        Log.d("Mr.Zhao", "onResponse: " + response.toString());

                    }

                }, new Response.ErrorListener() {

                    @Override

                    public void onErrorResponse(VolleyError error) {

                    }

                }){

                    @Override

                    protected Map<String, String> getParams() throws AuthFailureError {

                        Map<String, String> map = new HashMap<>();

                        map.put("pageNo", "1");

                        map.put("pageSize", "20");

                        map.put("serialIds", "2143,3404");

                        map.put("v", "4.0.0");

                        return map;

                    }

                };

                jsonObjectRequest.setTag("object");

                MyApp.getRequestQueue().add(jsonObjectRequest);

                break;

        }

    }

    @Override

    protected void onDestroy() {

        super.onDestroy();

        //  取消标记为  object 的 所有的请求

        MyApp.getRequestQueue().cancelAll("object");

    }

}

零散并发下载图片:

package qianfeng.com.day37_volley_pull;

import android.graphics.Bitmap;

import android.os.Bundle;

import android.support.v4.util.LruCache;

import android.support.v7.app.AppCompatActivity;

import android.view.View;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.Toast;

import com.android.volley.Response;

import com.android.volley.VolleyError;

import com.android.volley.toolbox.ImageLoader;

import com.android.volley.toolbox.ImageRequest;

import com.android.volley.toolbox.NetworkImageView;

import qianfeng.com.day37_volley_pull.app.MyApp;

public class ImageActivity extends AppCompatActivity {

    private ImageView show_iv;

    //2 使用缓存  Loader的方式加载图片

    //2.1  定义一个LruCache

    LruCache<String, Bitmap> lru;

    ImageLoader loader;

    private NetworkImageView netImageView;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_image);

        show_iv = (ImageView) findViewById(R.id.show_iv);

        initLoaderImage();

        //3. 使用  Volley框架 提供的   NetWorkImageView 来加载一张图片

        netImageView = (NetworkImageView) findViewById(R.id.netImageView);

        netImageView.setDefaultImageResId(R.mipmap.ic_launcher);

        //  3.1  加载图片 需要 先  初始化 ImageLoader

        netImageView.setImageUrl("http://img5.duitang.com/uploads/item/201511/02/20151102010720_yXnhP.thumb.224_0.jpeg",loader);

    }

    // s使用Loader 加载图片的方式

    private void initLoaderImage() {

        //2.2 实例化Lru

        int size = (int) (Runtime.getRuntime().maxMemory() / 8);

        lru = new LruCache<String, Bitmap>(size) {

            @Override

            protected int sizeOf(String key, Bitmap value) {

                return value.getByteCount();

            }

        };

        //2.3 实例化一个Loader

        loader = new ImageLoader(MyApp.getRequestQueue(), new ImageLoader.ImageCache() {

            @Override

            public Bitmap getBitmap(String url) {

                return lru.get(url);

            }

            @Override

            public void putBitmap(String url, Bitmap bitmap) {

                lru.put(url, bitmap);

            }

        });

    }

    //1.  使用请求的方式加载图片

    public void onClick(View view) {

        String path = "http://imgsrc.baidu.com/baike/pic/item/dcc451da81cb39db1a2e7b6ed5160924ab18301f.jpg";

        ImageRequest request = new ImageRequest(path, new Response.Listener<Bitmap>() {

            @Override

            public void onResponse(Bitmap response) {

                if (response != null)

                    show_iv.setImageBitmap(response);

                else

                    Toast.makeText(ImageActivity.this, "没图片", Toast.LENGTH_SHORT).show();

            }

        }, LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT, Bitmap.Config.RGB_565, new Response.ErrorListener() {

            @Override

            public void onErrorResponse(VolleyError error) {

            }

        });

        MyApp.getRequestQueue().add(request);

    }

    //2.3 加载图片

    public void loaderImage(View view) {

        String imagePath = "http://tupian.enterdesk.com/2013/mxy/10/12/3/5.jpg";

        // 获取监听器

        ImageLoader.ImageListener listener = loader.getImageListener(show_iv, R.mipmap.ic_launcher, R.mipmap.ic_launcher);

        //  获取图片

        loader.get(imagePath, listener);

    }

}

零散并发下载图片对应布局:

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context="qianfeng.com.day37_volley_pull.ImageActivity">

    <Button

        android:id="@+id/image_bt"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:onClick="onClick"

        android:text="获取网络图片" />

    <Button

        android:id="@+id/loader_bt"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:onClick="loaderImage"

        android:text="Loader" />

    <ImageView

        android:id="@+id/show_iv"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" />

    <com.android.volley.toolbox.NetworkImageView

        android:id="@+id/netImageView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" />

</LinearLayout>