Volley拓展框架——Netroid，以及与Volley的差异
转自：http://blog.csdn.net/brian512/article/details/50499423?ref=myread
Netroid是一个基于Volley实现的Android Http库。提供执行网络请求、缓存返回结果、批量图片加载、大文件断点下载的常见Http交互功能。致力于避免每个项目重复开发基础Http功能，实现显著地缩短开发周期的愿景。
功能上的区别：
作为Volley的拓展框架，netroid增加了大文件断点下载，并且netroid的可定制性更强。
实现上的区别：
1. 缓存的处理；
在volley中，缓存的过期时间是通过 ttl 和 softTtl 控制
<code class="hljs java has-numbering"> <span class="hljs-javadoc">/** True if the entry is expired. */</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">isExpired</span>() {
<span class="hljs-keyword">return</span> <span class="hljs-keyword">this</span>.ttl < System.currentTimeMillis();
}
<span class="hljs-javadoc">/** True if a refresh is needed from the original data source. */</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">refreshNeeded</span>() {
<span class="hljs-keyword">return</span> <span class="hljs-keyword">this</span>.softTtl < System.currentTimeMillis();
}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li></ul>
而这两个值的来源是HttpHeaderParser.parseCacheHeaders
<code class="hljs cs has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-keyword">static</span> Cache.Entry <span class="hljs-title">parseCacheHeaders</span>(NetworkResponse response) {
<span class="hljs-keyword">long</span> now = System.currentTimeMillis();
<span class="hljs-keyword">long</span> serverDate = <span class="hljs-number">0</span>;
<span class="hljs-keyword">long</span> lastModified = <span class="hljs-number">0</span>;
<span class="hljs-keyword">long</span> serverExpires = <span class="hljs-number">0</span>;
<span class="hljs-keyword">long</span> softExpire = <span class="hljs-number">0</span>;
<span class="hljs-keyword">long</span> finalExpire = <span class="hljs-number">0</span>;
<span class="hljs-keyword">long</span> maxAge = <span class="hljs-number">0</span>;
<span class="hljs-keyword">long</span> staleWhileRevalidate = <span class="hljs-number">0</span>;
boolean hasCacheControl = <span class="hljs-keyword">false</span>;
boolean mustRevalidate = <span class="hljs-keyword">false</span>;
String serverEtag = <span class="hljs-keyword">null</span>;
headerValue = headers.<span class="hljs-keyword">get</span>(<span class="hljs-string">"Date"</span>);
<span class="hljs-keyword">if</span> (headerValue != <span class="hljs-keyword">null</span>) {
serverDate = parseDateAsEpoch(headerValue);
} headerValue = headers.<span class="hljs-keyword">get</span>(<span class="hljs-string">"Cache-Control"</span>);
<span class="hljs-keyword">if</span> (headerValue != <span class="hljs-keyword">null</span>) {
hasCacheControl = <span class="hljs-keyword">true</span>;
String[] tokens = headerValue.split(<span class="hljs-string">","</span>);
<span class="hljs-keyword">for</span> (<span class="hljs-keyword">int</span> i = <span class="hljs-number">0</span>; i < tokens.length; i++) {
String token = tokens[i].trim();
<span class="hljs-keyword">if</span> (token.equals(<span class="hljs-string">"no-cache"</span>) || token.equals(<span class="hljs-string">"no-store"</span>)) {
<span class="hljs-keyword">return</span> <span class="hljs-keyword">null</span>;
} <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (token.startsWith(<span class="hljs-string">"max-age="</span>)) {
<span class="hljs-keyword">try</span> {
maxAge = Long.parseLong(token.substring(<span class="hljs-number">8</span>));
} <span class="hljs-keyword">catch</span> (Exception e) {
}
} <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (token.startsWith(<span class="hljs-string">"stale-while-revalidate="</span>)) {
<span class="hljs-keyword">try</span> {
staleWhileRevalidate = Long.parseLong(token.substring(<span class="hljs-number">23</span>));
} <span class="hljs-keyword">catch</span> (Exception e) {
}
} <span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (token.equals(<span class="hljs-string">"must-revalidate"</span>) || token.equals(<span class="hljs-string">"proxy-revalidate"</span>)) {
mustRevalidate = <span class="hljs-keyword">true</span>;
}
}
}
headerValue = headers.<span class="hljs-keyword">get</span>(<span class="hljs-string">"Expires"</span>);
<span class="hljs-keyword">if</span> (headerValue != <span class="hljs-keyword">null</span>) {
serverExpires = parseDateAsEpoch(headerValue);
}
headerValue = headers.<span class="hljs-keyword">get</span>(<span class="hljs-string">"Last-Modified"</span>);
<span class="hljs-keyword">if</span> (headerValue != <span class="hljs-keyword">null</span>) {
lastModified = parseDateAsEpoch(headerValue);
<span class="hljs-comment">// Cache-Control takes precedence over an Expires header, even if both exist and Expires is more restrictive.</span>
<span class="hljs-comment">// 如果服务器返回的header中有Cache-Control字段，则可以按照制定的规则进行设定</span>
<span class="hljs-keyword">if</span> (hasCacheControl) {
softExpire = now + maxAge * <span class="hljs-number">1000</span>;
finalExpire = mustRevalidate
? softExpire
: softExpire + staleWhileRevalidate * <span class="hljs-number">1000</span>;
}
<span class="hljs-comment">// 若服务器返回的header中包含Expires和Date字段</span>
<span class="hljs-keyword">else</span> <span class="hljs-keyword">if</span> (serverDate > <span class="hljs-number">0</span> && serverExpires >= serverDate) {
<span class="hljs-comment">// Default semantic for Expire header in HTTP specification is softExpire.</span>
softExpire = now + (serverExpires - serverDate);
finalExpire = softExpire;
}
Cache.Entry entry = <span class="hljs-keyword">new</span> Cache.Entry();
entry.data = response.data;
entry.etag = serverEtag;
entry.softTtl = softExpire;
entry.ttl = finalExpire;
entry.serverDate = serverDate;
entry.lastModified = lastModified;
<span class="hljs-keyword">return</span> entry;
}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li><li>55</li><li>56</li><li>57</li><li>58</li><li>59</li><li>60</li><li>61</li><li>62</li><li>63</li><li>64</li><li>65</li><li>66</li><li>67</li><li>68</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li><li>51</li><li>52</li><li>53</li><li>54</li><li>55</li><li>56</li><li>57</li><li>58</li><li>59</li><li>60</li><li>61</li><li>62</li><li>63</li><li>64</li><li>65</li><li>66</li><li>67</li><li>68</li></ul>
根据上述代码中的中文注释看，若服务器返回的header中没有Cache-Control，Expires，Date等字段，则 ttl 和 softExpire 的值均为默认的0，从而使得缓存永远是过期的，其影响是缓存不仅不能起效，反而每次网络请求都需要更新缓存，最后就是拖累整体性能。
为此，netroid采用expireTime字段替代了 ttl 和 softExpire ，每次发起请求时，需指定过期时间
<code class="hljs java has-numbering"> <span class="hljs-comment">// com.duowan.mobile.netroid.Request.java</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">setCacheExpireTime</span>(TimeUnit timeUnit, <span class="hljs-keyword">int</span> amount) {
<span class="hljs-keyword">this</span>.mCacheExpireTime = System.currentTimeMillis() + timeUnit.toMillis(amount);
}
<span class="hljs-keyword">public</span> <span class="hljs-keyword">final</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">shouldCache</span>() {
<span class="hljs-keyword">return</span> mCacheExpireTime > <span class="hljs-number">0</span>;
}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li></ul>
从上述代码看出，若没有设置过期时间时，不会产生缓存
<code class="hljs java has-numbering"> <span class="hljs-javadoc">/** True if the entry is expired. */</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">isExpired</span>() {
<span class="hljs-keyword">return</span> expireTime < System.currentTimeMillis();
}
<span class="hljs-javadoc">/** True if a refresh is needed from the original data source. */</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">boolean</span> <span class="hljs-title">refreshNeeded</span>() {
<span class="hljs-comment">// still unimplemented, might be use a constant like 'refreshTime'?</span>
<span class="hljs-keyword">return</span> <span class="hljs-keyword">this</span>.expireTime < System.currentTimeMillis();
}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li></ul>
2. 网络数据处理；
首先贴一段带注释的代码：
<code class="hljs java has-numbering"> <span class="hljs-keyword">public</span> NetworkResponse <span class="hljs-title">performRequest</span>(Request<?> request) <span class="hljs-keyword">throws</span> VolleyError {
<span class="hljs-comment">// Determine if request had non-http perform.</span>
<span class="hljs-comment">// 若该请求不需要访问网络，则直接复写perform方法。使用场景如，加载数据库的数据，或者加载本地图片，使用此框架可以统一处理此类耗时操作</span>
NetworkResponse networkResponse = request.perform();
<span class="hljs-keyword">if</span> (networkResponse != <span class="hljs-keyword">null</span>)
<span class="hljs-keyword">return</span> networkResponse;
<span class="hljs-keyword">long</span> requestStart = SystemClock.elapsedRealtime();
<span class="hljs-keyword">while</span> (<span class="hljs-keyword">true</span>) {
<span class="hljs-comment">// If the request was cancelled already,</span>
<span class="hljs-comment">// do not perform the network request.</span>
<span class="hljs-keyword">if</span> (request.isCanceled()) {
request.finish(<span class="hljs-string">"perform-discard-cancelled"</span>);
mDelivery.postCancel(request);
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> NetworkError(networkResponse);
}
HttpResponse httpResponse = <span class="hljs-keyword">null</span>;
<span class="hljs-keyword">byte</span>[] responseContents = <span class="hljs-keyword">null</span>;
<span class="hljs-keyword">try</span> {
<span class="hljs-comment">// prepare to perform this request, normally is reset the request headers.</span>
<span class="hljs-comment">// 此方法默认实现为空，若请求有需要预处理的话，该设计也是极好的。使用场景如，在进行大文件断点下载时，需要设置Range头字段，但是网络异常进行retry时就不太好处理range了，但是有这个方法就很简单了</span>
request.prepare();
httpResponse = mHttpStack.performRequest(request);
StatusLine statusLine = httpResponse.getStatusLine();
<span class="hljs-keyword">int</span> statusCode = statusLine.getStatusCode();
<span class="hljs-keyword">if</span> (statusCode < <span class="hljs-number">200</span> || statusCode > <span class="hljs-number">299</span>) <span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> IOException();
<span class="hljs-comment">// 此方法的默认实现为volley的实现方法，但是可以复写该方法。volley的实现方式是直接把请求到的数据转为byte[]，此方式会限制请求的数据量不能太大，否则会OOM。</span>
<span class="hljs-comment">// 若下载大文件时，就得复写这个方法，将网络请求的数据流读写到文件，而不是内存</span>
responseContents = request.handleResponse(httpResponse, mDelivery);
<span class="hljs-comment">// if the request is slow, log it.</span>
<span class="hljs-keyword">long</span> requestLifetime = SystemClock.elapsedRealtime() - requestStart;
logSlowRequests(requestLifetime, request, responseContents, statusLine);
<span class="hljs-keyword">return</span> <span class="hljs-keyword">new</span> NetworkResponse(statusCode, responseContents, parseCharset(httpResponse));
} <span class="hljs-keyword">catch</span> (SocketTimeoutException e) {
attemptRetryOnException(<span class="hljs-string">"socket"</span>, request, <span class="hljs-keyword">new</span> TimeoutError());
} <span class="hljs-keyword">catch</span> (ConnectTimeoutException e) {
attemptRetryOnException(<span class="hljs-string">"connection"</span>, request, <span class="hljs-keyword">new</span> TimeoutError());
} <span class="hljs-keyword">catch</span> (MalformedURLException e) {
<span class="hljs-keyword">throw</span> <span class="hljs-keyword">new</span> RuntimeException(<span class="hljs-string">"Bad URL "</span> + request.getUrl(), e);
} <span class="hljs-keyword">catch</span> (IOException e) {
。。。
}
}
}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li><li>36</li><li>37</li><li>38</li><li>39</li><li>40</li><li>41</li><li>42</li><li>43</li><li>44</li><li>45</li><li>46</li><li>47</li><li>48</li><li>49</li><li>50</li></ul>
3. 数据请求过程回调；
在volley的实现中，是通过ExecutorDelivery将数据请求的结果回调给调用者。
<code class="hljs java has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">interface</span> <span class="hljs-title">ResponseDelivery</span> {</span>
<span class="hljs-javadoc">/**
* Parses a response from the network or cache and delivers it.
*/</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">postResponse</span>(Request<?> request, Response<?> response);
<span class="hljs-javadoc">/**
* Parses a response from the network or cache and delivers it. The provided
* Runnable will be executed after delivery.
*/</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">postResponse</span>(Request<?> request, Response<?> response, Runnable runnable);
<span class="hljs-javadoc">/**
* Posts an error for the given request.
*/</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">postError</span>(Request<?> request, VolleyError error);
}
</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li></ul>
netroid在此基础上增加了一些回调：
<code class="hljs java has-numbering"><span class="hljs-keyword">public</span> <span class="hljs-class"><span class="hljs-keyword">interface</span> <span class="hljs-title">Delivery</span> {</span>
<span class="hljs-javadoc">/** Posts request finished callback for the given request. */</span>
<span class="hljs-keyword">void</span> postFinish(Request<?> request);
<span class="hljs-javadoc">/** Parses a response from the network or cache and delivers it. */</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">postResponse</span>(Request<?> request, Response<?> response);
<span class="hljs-javadoc">/**
* Parses a response from the network or cache and delivers it. The provided
* Runnable will be executed after delivery.
*/</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">postResponse</span>(Request<?> request, Response<?> response, Runnable runnable);
<span class="hljs-javadoc">/** Posts an error for the given request. */</span>
<span class="hljs-keyword">public</span> <span class="hljs-keyword">void</span> <span class="hljs-title">postError</span>(Request<?> request, VolleyError error);
<span class="hljs-javadoc">/** Posts a cancel callback for the given request. */</span>
<span class="hljs-keyword">void</span> postCancel(Request<?> request);
<span class="hljs-javadoc">/** Posts starting execute callback for the given request. */</span>
<span class="hljs-keyword">void</span> postPreExecute(Request<?> request);
<span class="hljs-javadoc">/** Posts cache used callback for the given request. */</span>
<span class="hljs-keyword">void</span> postUsedCache(Request<?> request);
<span class="hljs-javadoc">/** Posts networking callback for the given request. */</span>
<span class="hljs-keyword">void</span> postNetworking(Request<?> request);
<span class="hljs-javadoc">/** Posts request retry callback for the given request. */</span>
<span class="hljs-keyword">void</span> postRetry(Request<?> request);
<span class="hljs-javadoc">/** Posts file download progress stat. */</span>
<span class="hljs-keyword">void</span> postDownloadProgress(Request<?> request, <span class="hljs-keyword">long</span> fileSize, <span class="hljs-keyword">long</span> downloadedSize);
}</code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li><li>32</li><li>33</li><li>34</li><li>35</li></ul>
可以看出，这些回调基本覆盖了请求过程中的关键点，主要是有postDownloadProgress方法，进行回调文件下载进度。
<code class="hljs avrasm has-numbering"> // <span class="hljs-keyword">com</span><span class="hljs-preprocessor">.duowan</span><span class="hljs-preprocessor">.mobile</span><span class="hljs-preprocessor">.netroid</span><span class="hljs-preprocessor">.NetworkDispatcher</span><span class="hljs-preprocessor">.java</span>
request<span class="hljs-preprocessor">.addMarker</span>(<span class="hljs-string">"network-queue-take"</span>)<span class="hljs-comment">;</span>
mDelivery<span class="hljs-preprocessor">.postPreExecute</span>(request)<span class="hljs-comment">;</span>
// If the request was cancelled already,
// do not perform the network request.
if (request<span class="hljs-preprocessor">.isCanceled</span>()) {
request<span class="hljs-preprocessor">.finish</span>(<span class="hljs-string">"network-discard-cancelled"</span>)<span class="hljs-comment">;</span>
mDelivery<span class="hljs-preprocessor">.postCancel</span>(request)<span class="hljs-comment">;</span>
mDelivery<span class="hljs-preprocessor">.postFinish</span>(request)<span class="hljs-comment">;</span>
continue<span class="hljs-comment">;</span>
}
// Perform the network request.
NetworkResponse networkResponse = mNetwork<span class="hljs-preprocessor">.performRequest</span>(request)<span class="hljs-comment">;</span>
request<span class="hljs-preprocessor">.addMarker</span>(<span class="hljs-string">"network-http-complete"</span>)<span class="hljs-comment">;</span>
// Parse the response here on the worker thread.
Response<?> response = request<span class="hljs-preprocessor">.parseNetworkResponse</span>(networkResponse)<span class="hljs-comment">;</span>
request<span class="hljs-preprocessor">.addMarker</span>(<span class="hljs-string">"network-parse-complete"</span>)<span class="hljs-comment">;</span>
// Write to cache if applicable.
if (mCache != null && request<span class="hljs-preprocessor">.shouldCache</span>() && response<span class="hljs-preprocessor">.cacheEntry</span> != null) {
response<span class="hljs-preprocessor">.cacheEntry</span><span class="hljs-preprocessor">.expireTime</span> = request<span class="hljs-preprocessor">.getCacheExpireTime</span>()<span class="hljs-comment">;</span>
mCache<span class="hljs-preprocessor">.putEntry</span>(request<span class="hljs-preprocessor">.getCacheKey</span>(), response<span class="hljs-preprocessor">.cacheEntry</span>)<span class="hljs-comment">;</span>
request<span class="hljs-preprocessor">.addMarker</span>(<span class="hljs-string">"network-cache-written"</span>)<span class="hljs-comment">;</span>
}
// Post the response back.
request<span class="hljs-preprocessor">.markDelivered</span>()<span class="hljs-comment">;</span>
mDelivery<span class="hljs-preprocessor">.postResponse</span>(request, response)<span class="hljs-comment">;</span></code><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li></ul><ul class="pre-numbering"><li>1</li><li>2</li><li>3</li><li>4</li><li>5</li><li>6</li><li>7</li><li>8</li><li>9</li><li>10</li><li>11</li><li>12</li><li>13</li><li>14</li><li>15</li><li>16</li><li>17</li><li>18</li><li>19</li><li>20</li><li>21</li><li>22</li><li>23</li><li>24</li><li>25</li><li>26</li><li>27</li><li>28</li><li>29</li><li>30</li><li>31</li></ul>
从上述代码看出，回调确实很多，若在这些回调中添加太多操作的话，肯定会影响数据请求的速度。
总的来说，netroid相对volley的改进还是不错的，这也是这两天看代码的总结，如有遗漏，后面再补充！