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>