Android中volley封装实践记录（二）

砸漏

修改于 2023-09-23 19:20:03

5290

修改于 2023-09-23 19:20:03

文章被收录于专栏：恩蓝脚本

前言

关于android的volley封装之前写过一篇文章，见链接（https://www.zalou.cn/article/155875.htm）。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：