android开发常用网络样例总结

package com.lsh.netdemo.net; import android.graphics.Bitmap; import android.util.Log; import android.util.LruCache; import android.widget.ImageView; import com.android.volley.NetworkResponse; import com.android.volley.Request; import com.android.volley.RequestQueue; import com.android.volley.Response; import com.android.volley.VolleyError; import com.android.volley.toolbox.HttpHeaderParser; import com.android.volley.toolbox.ImageLoader; import com.android.volley.toolbox.ImageRequest; import com.android.volley.toolbox.StringRequest; import com.lsh.netdemo.MyApplication; import com.lsh.netdemo.R; import com.lsh.netdemo.activity.BaseActivity; import com.lsh.netdemo.bean.ListData; import com.lsh.netdemo.util.JsonUtil; import java.io.UnsupportedEncodingException; import java.util.List; public class VolleyHelper { static String host_address = "http://10.0.2.2:8080/listdata/"; private static ImageLoader.ImageCache sImageCache; private static LruCache<String, Bitmap> sLruCache; private static ImageLoader sImageLoader; //volley需要一个请求队列，但是他必须在Application中声明 private static RequestQueue sRequestQueue = MyApplication.getRequestQueue(); /** * 1.使用自定义request的方式去获取json数据,不会有乱码 */ public static void getData(String url, final List<ListData.Data> dataList, final BaseActivity.InnerAdapter adapter) { Request<String> request = new Request<String>(Request.Method.GET, host_address + url, null) { @Override protected Response<String> parseNetworkResponse(NetworkResponse response) { byte[] data = response.data; // Entry是指定缓存类型中的条目,注意需要解析获取，或者取消缓存 return Response.success(new String(data), HttpHeaderParser.parseCacheHeaders(response)); } @Override protected void deliverResponse(String response) { ListData parse = JsonUtil.parse(ListData.class, response); dataList.addAll(parse.list); adapter.notifyDataSetChanged(); } }; // 取消缓存 // request.setShouldCache(false); sRequestQueue.add(request); } /** * 2.使用默认定义的StringRequest处理json数据 * * @param url * @param dataList */ public static void getString(String url, final List<ListData.Data> dataList, final BaseActivity.InnerAdapter innerAdapter) { sRequestQueue.add(new StringRequest(Request.Method.GET, host_address + url, new Response.Listener<String>() { @Override public void onResponse(String response) { ListData parse = JsonUtil.parse(ListData.class, response); dataList.addAll(parse.list); innerAdapter.notifyDataSetChanged(); } }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { error.printStackTrace(); Log.e("tag", "error"); } }) { /** * 重写该方法，已达到修复文字乱码的问题 * @param response * @return */ @Override protected Response<String> parseNetworkResponse(NetworkResponse response) { String parsed; try { // 源码中实现是获取网络响应头中的文字编码，与U8不同时会造成乱码 // parsed = new String(response.data, HttpHeaderParser.parseCharset(response.headers)); parsed = new String(response.data, "UTF-8"); } catch (UnsupportedEncodingException e) { parsed = new String(response.data); } return Response.success(parsed, HttpHeaderParser.parseCacheHeaders(response)); } }); } /** * 使用request去获取对应的bitmap,低效率，很慢，画质差 * * @param imageView * @param url */ public static void getViewImage_request(final ImageView imageView, final String url) { // 设置标记进行校验 imageView.setTag(url); sRequestQueue.add(new ImageRequest(host_address + url, new Response.Listener<Bitmap>() { @Override public void onResponse(Bitmap response) { // 校验标记 if (imageView.getTag().equals(url)) imageView.setImageBitmap(response); } }, 0, 0, Bitmap.Config.ARGB_8888, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { } })); } /** * 使用volley的ImageLoader来加载图片,高效，很慢，画质优秀 * * @param url * @param imageView */ public static void getViewImage_loader(String url, ImageView imageView) { // volley没有实现默认的缓存，需要我们自己实现 // 1.初始化一个默认大小的内存缓存 if (sLruCache == null) { sLruCache = getLruCache(); } // 2.将对应的bitmap缓存存取方式进行封装 if (sImageCache == null) sImageCache = new ImageLoader.ImageCache() { @Override public Bitmap getBitmap(String url) { return sLruCache.get(url); } @Override public void putBitmap(String url, Bitmap bitmap) { sLruCache.put(url, bitmap); } }; // 3.根据已经创建好的imageCache和queue来初始化一个新的imageLoader if (sImageLoader == null) sImageLoader = new ImageLoader(MyApplication.getRequestQueue(), sImageCache); // 4.为对应的imageView生成一个默认的imageListener，并可以设置初始图片和失败图片 ImageLoader.ImageListener listener = ImageLoader.getImageListener(imageView, R.mipmap.ic_launcher, R.mipmap.ic_launcher); // 5.使用ImageLoader的get请求这个加载 sImageLoader.get(host_address + url, listener); } /** * 获取一个LruCache */ private static LruCache getLruCache() { long maxMemory = Runtime.getRuntime().maxMemory(); long cacheSize = maxMemory / 8; sLruCache = new LruCache<String, Bitmap>((int) (cacheSize / 1024)) { protected int sizeOf(String key, Bitmap value) { return value.getRowBytes() * value.getHeight() / 1024; } }; return sLruCache; } }