Android中volley封装实践记录（二）

2019-10-21 21:25:44

字体：大中小

来源：转载

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前言

关于android的volley 封装之前写过一篇文章，见链接（http://www.vevb.com/kaifa/android/345045.html）。这篇文章主要是换种方式进行封装，具体步骤如下所示。

步骤如下

1.创建Request，并设置相应的参数：

public class CommonJsonObjectRequest extends JsonObjectRequest { private String TAG = this.getClass().getSimpleName(); /* * code=1:处理成功； */ public static final int CODE_SUCCESS = 100; private Context mContext; private JSONObject mJsonRequest; public CommonJsonObjectRequest(Context context, int method, String url,     JSONObject jsonRequest, Response.Listener<JSONObject> listener,     Response.ErrorListener errorListener) { super(method, url, jsonRequest, listener, errorListener); init(context, jsonRequest); } /** * @param context * @param url * @param jsonRequest * @param listener * @param errorListener */ public CommonJsonObjectRequest(Context context, String url, JSONObject jsonRequest,     Response.Listener<JSONObject> listener, Response.ErrorListener errorListener) { super(url, jsonRequest, listener, errorListener); if (jsonRequest != null) {  Log.d(TAG, jsonRequest.toString()); } init(context, jsonRequest); } /** * @param context * @param jsonRequest */ private void init(Context context, JSONObject jsonRequest) { this.mContext = context.getApplicationContext(); this.mJsonRequest = jsonRequest; setRetryPolicy(new DefaultRetryPolicy(10 * 1000, 0, 0)); } @Override public Map<String, String> getHeaders() throws AuthFailureError { Map<String, String> headersMap = new HashMap<>(); //do your business requirement return headersMap; }}

所做的工作也很简单，去配置网络访问RetryPolicy,比如超时时间，最大的重试次数。例外也会根据业务要求在请求的头部加入token等标识。

2.通过工厂模式创建请求队列，volley内部会有两种构造方式，同步请求或者异步请求，通过设置ResponseDelivery 可以实现。

public interface ResponseDelivery { /** * Parses a response from the network or cache and delivers it. */ public void postResponse(Request<?> request, Response<?> response); /** * Parses a response from the network or cache and delivers it. The provided * Runnable will be executed after delivery. */ public void postResponse(Request<?> request, Response<?> response, Runnable runnable); /** * Posts an error for the given request. */ public void postError(Request<?> request, VolleyError error);}

这个工厂的代码如下：

/** * 网络请求队列工厂类 */public class RequestQueueFactory { private static RequestQueue sRequestQueue; private static RequestQueue sAsynRequestQueue; private static int ASYN_QUEUE_THREAD_POOL_SIZE = 3; private RequestQueueFactory() { } /** * 获取默认RequestQueue，回调是同步到主线程的 * * @param context * @return */ public synchronized static RequestQueue getRequestQueue(Context context) { if (sRequestQueue == null) {  OkHttpClient okHttpClient = new OkHttpClient.Builder().build();  OkHttpStack stack = new OkHttpStack(okHttpClient);  sRequestQueue = Volley.newRequestQueue(context, stack); } return sRequestQueue; } /** * 获取异步RequestQueue，回调是在异步线程的 * * @param context * @return */ public synchronized static RequestQueue getAsynRequeQueueRespond(  final Context context) { if (sAsynRequestQueue == null) {  sAsynRequestQueue = getAsynRequeQueueRespond(context,   ASYN_QUEUE_THREAD_POOL_SIZE); } return sAsynRequestQueue; } private static RequestQueue getAsynRequeQueueRespond(final Context context,        int threadPoolSize) { File cacheDir = new File(context.getCacheDir(), "volley_asyn"); OkHttpClient okHttpClient = new OkHttpClient.Builder().build(); OkHttpStack stack = new OkHttpStack(okHttpClient); Network network = new BasicNetwork(stack); RequestQueue queue = new RequestQueue(new DiskBasedCache(cacheDir),  network, threadPoolSize, new ExecutorDelivery(  AsyncTask.SERIAL_EXECUTOR)); queue.start(); return queue; }}

在代码中有这样两行代码：

 if (sRequestQueue == null) {  OkHttpClient okHttpClient = new OkHttpClient.Builder().build();  OkHttpStack stack = new OkHttpStack(okHttpClient);  sRequestQueue = Volley.newRequestQueue(context, stack); }

这里是使用了okhttpstack,如果不进行设置，内部默认的会设置一个stack;

 if (stack == null) {  if (Build.VERSION.SDK_INT >= 9) {  stack = new HurlStack();  } else {  // Prior to Gingerbread, HttpUrlConnection was unreliable.  // See: http://android-developers.blogspot.com/2011/09/androids-http-clients.html  stack = new HttpClientStack(AndroidHttpClient.newInstance(userAgent));  } }

okhttpstack类如下：

/** * 使用OKHttp作为底层的HttpStack */public class OkHttpStack implements HttpStack { private final OkHttpClient client; public OkHttpStack(OkHttpClient client) { this.client = client; } private static HttpEntity entityFromOkHttpResponse(Response response) throws IOException { BasicHttpEntity entity = new BasicHttpEntity(); ResponseBody body = response.body(); entity.setContent(body.byteStream()); entity.setContentLength(body.contentLength()); entity.setContentEncoding(response.header("Content-Encoding")); if (body.contentType() != null) {  entity.setContentType(body.contentType().type()); } return entity; } @SuppressWarnings("deprecation") private static void setConnectionParametersForRequest  (okhttp3.Request.Builder builder, Request<?> request)  throws IOException, AuthFailureError { switch (request.getMethod()) {  case Request.Method.DEPRECATED_GET_OR_POST:  byte[] postBody = request.getPostBody();  if (postBody != null) {   builder.post(RequestBody.create    (MediaType.parse(request.getPostBodyContentType()), postBody));  }  break;  case Request.Method.GET:  builder.get();  break;  case Request.Method.DELETE:  builder.delete();  break;  case Request.Method.POST:  builder.post(createRequestBody(request));  break;  case Request.Method.PUT:  builder.put(createRequestBody(request));  break;  case Request.Method.HEAD:  builder.head();  break;  case Request.Method.OPTIONS:  builder.method("OPTIONS", null);  break;  case Request.Method.TRACE:  builder.method("TRACE", null);  break;  case Request.Method.PATCH:  builder.patch(createRequestBody(request));  break;  default:  throw new IllegalStateException("Unknown method type."); } } private static RequestBody createRequestBody(Request request) throws AuthFailureError { final byte[] body = request.getBody(); if (body == null) return null; return RequestBody.create(MediaType.parse(request.getBodyContentType()), body); } private static ProtocolVersion parseProtocol(final Protocol protocol) { switch (protocol) {  case HTTP_1_0:  return new ProtocolVersion("HTTP", 1, 0);  case HTTP_1_1:  return new ProtocolVersion("HTTP", 1, 1);  case SPDY_3:  return new ProtocolVersion("SPDY", 3, 1);  case HTTP_2:  return new ProtocolVersion("HTTP", 2, 0); } throw new IllegalAccessError("Unkwown protocol"); } @Override public HttpResponse performRequest(Request<?> request, Map<String, String> additionalHeaders)  throws IOException, AuthFailureError { int timeoutMs = request.getTimeoutMs(); OkHttpClient client = this.client.newBuilder()  .readTimeout(timeoutMs, TimeUnit.MILLISECONDS)  .connectTimeout(timeoutMs, TimeUnit.MILLISECONDS)  .writeTimeout(timeoutMs, TimeUnit.MILLISECONDS)  .build(); okhttp3.Request.Builder okHttpRequestBuilder = new okhttp3.Request.Builder(); Map<String, String> headers = request.getHeaders(); for (Map.Entry<String,String> entry : headers.entrySet()) {  okHttpRequestBuilder.addHeader(entry.getKey(), entry.getValue()); } for (Map.Entry<String,String> entry : additionalHeaders.entrySet()) {  okHttpRequestBuilder.addHeader(entry.getKey(), entry.getValue()); }// for (final String name : headers.keySet()) { //entrySet的遍历效率比keySet高上一个遍历元素的速度//  okHttpRequestBuilder.addHeader(name, headers.get(name));// }// for (final String name : additionalHeaders.keySet()) {//  okHttpRequestBuilder.addHeader(name, additionalHeaders.get(name));// } setConnectionParametersForRequest(okHttpRequestBuilder, request); okhttp3.Request okhttp3Request = okHttpRequestBuilder.url(request.getUrl()).build(); Response okHttpResponse = client.newCall(okhttp3Request).execute(); StatusLine responseStatus = new BasicStatusLine  (   parseProtocol(okHttpResponse.protocol()),   okHttpResponse.code(),   okHttpResponse.message()  ); BasicHttpResponse response = new BasicHttpResponse(responseStatus); response.setEntity(entityFromOkHttpResponse(okHttpResponse)); Headers responseHeaders = okHttpResponse.headers(); for (int i = 0, len = responseHeaders.size(); i < len; i++) {  final String name = responseHeaders.name(i), value = responseHeaders.value(i);  if (name != null) {  response.addHeader(new BasicHeader(name, value));  } } return response; }}

其中核心代码在performRequest方法中。

3.封装基类。基类使用abstract会更灵活，子类可以选择性的重写方法。

/** * 网络处理基类 */public abstract class BaseNetModel { protected RequestQueue requestQueue; protected Context context; protected Object mTag; protected BaseNetModel(Context context) { this.context = context.getApplicationContext(); requestQueue = RequestQueueFactory.getAsynRequeQueueRespond(this.context); } protected BaseNetModel(Context context, boolean isAsyn) { this.context = context.getApplicationContext(); requestQueue = isAsyn ? RequestQueueFactory.getAsynRequeQueueRespond(this.context)  : RequestQueueFactory.getRequestQueue(context); } /** * 推荐用页面ClassName+时间戳 * * @param tag */ public void setTag(Object tag) { this.mTag = tag; } public void destroy() { if (mTag != null) {  cancelTaskByTag(mTag); } requestQueue = null; context = null; } public void cancelTaskByTag(Object tag) { if (requestQueue != null) {  requestQueue.cancelAll(tag); } } public void addRequest(String path, JSONObject jsonRequest, Response.Listener<JSONObject> listener, Response.ErrorListener errorListener) { addRequest(path, true, jsonRequest, listener, errorListener); } /** * @param path  不带域名的接口路径 * @param withTag 是否带上页面的tag * @param jsonRequest * @param listener * @param errorListener */ public void addRequest(String path, boolean withTag, JSONObject jsonRequest, Response.Listener<JSONObject> listener, Response.ErrorListener errorListener) { addRequestUrl(path, withTag, jsonRequest, listener, errorListener); } /** * @param url  完整接口地址 * @param withTag * @param jsonRequest * @param listener * @param errorListener */ public void addRequestUrl(String url, boolean withTag, JSONObject jsonRequest, Response.Listener<JSONObject> listener, Response.ErrorListener errorListener) { if (jsonRequest == null) {  jsonRequest = new JSONObject(); } CommonJsonObjectRequest request = new CommonJsonObjectRequest(context, url, jsonRequest, listener, errorListener); if (withTag && mTag != null) {  request.setTag(mTag); } requestQueue.add(request); }}

4.逻辑封装。

这里选用的是一个新闻的接口，这种接口可以在聚合数据上申请，有的收费，有的免费。

public class NewsModel extends BaseNetModel { public NewsModel(Context context) { super(context); } public NewsModel(Context context, boolean isAsyn) { super(context, isAsyn); } public void getInfo(Response.Listener<JSONObject> listener, Response.ErrorListener errorListener) throws Exception { JSONObject jsonObject = new JSONObject(); addRequest(INetConstant.NEWS, jsonObject, listener, errorListener); }}

接口的地址为：（http://v.juhe.cn/toutiao/index?type=&key=b2f8e4aeacfa310cabfadd5189bbe4d5）

5.开始使用。

 NewsModel newsModel = new NewsModel(getActivity()); try {  newsModel.getInfo(new Response.Listener<JSONObject>() {  @Override  public void onResponse(final JSONObject response) {   ThreadUtils.runInUIThread(new Runnable() {   @Override   public void run() {    News news = new Gson().fromJson(response.toString(), News.class);    mAdapter.setData(news.getResult().getData());   }   });  }  }, new Response.ErrorListener() {  @Override  public void onErrorResponse(VolleyError error) {  }  }); } catch (Exception e) {  e.printStackTrace(); }

最后放一张图：