path: root/files/zh-cn/web/api/cache/add/index.html

---
title: Cache.add()
slug: Web/API/Cache/add
translation_of: Web/API/Cache/add
---
<p>{{APIRef("Service Workers API")}}{{SeeCompatTable}}</p>

<p>{{domxref("Cache")}}接口的 <strong><code>add()</code></strong>方法接受一个URL作为参数，请求参数指定的URL，并将返回的response对象添加到给定的cache中。 <code>add()</code> 方法在功能上等同于以下代码:</p>

<pre class="brush: js">fetch(url).then(function (response) {
  if (!response.ok) {
    throw new TypeError('bad response status');
  }
  return cache.put(url, response);
})</pre>

<p>对于更复杂的操作，您可以直接使用{{domxref("Cache.put","Cache.put()")}}这个API。</p>

<div class="note">
<p><span style="font-size: 14px;"><strong>注意</strong></span>: <code>add()</code> 将会覆盖之前存储在cache中与request匹配的任何key/value对。</p>
</div>

<div class="note">
<p><span style="font-size: 14px;"><strong>注意</strong></span>: 之前的Cache  (Blink 和 Gecko内核版本) 在实现{{domxref("Cache.add")}}, {{domxref("Cache.addAll")}}, 和 {{domxref("Cache.put")}} 的策略是在response结果完全写入缓存后才会resolve当前的promise。更新后的规范版本中一旦条目被记录到数据库就会resolve当前的promise，即使当前response结果还在传输中。</p>
</div>

<h2 id="语法">语法</h2>

<pre class="sytaxbox"><em>cache</em>.add(<em>request</em>).then(function() {
  //request has been added to the cache
});
</pre>

<h3 id="参数">参数</h3>

<dl>
 <dt>request</dt>
 <dd>要添加到cache的request。它可以是一个 {{domxref("Request")}} 对象，也可以是 URL。</dd>
</dl>

<h3 id="返回值">返回值</h3>

<p>void返回值的 {{jsxref("Promise")}} </p>

<h3 id="Exceptions">Exceptions</h3>

<table class="standard-table">
 <thead>
  <tr>
   <th scope="col"><strong>Exception</strong></th>
   <th scope="col"><strong>Happens when</strong></th>
  </tr>
 </thead>
 <tbody>
  <tr>
   <td><code>TypeError</code></td>
   <td>
    <p>URL的协议不是 <code>http</code> 或 <code>https。</code></p>

    <p>请求返回的http状态码不是2xx (不是一个成功的响应) 。这种情况常常发生在请求不成功，或者是一个没有配置CORS的跨域请求（这种情况下返回的状态码永远是0）。</p>
   </td>
  </tr>
 </tbody>
</table>

<h2 id="示例">示例</h2>

<p>下面的代码块等待 {{domxref("InstallEvent")}} 事件触发，然后运行 {{domxref("ExtendableEvent.waitUntil","waitUntil")}} 来处理该应用程序的安装过程。 包括调用 {{domxref("CacheStorage.open")}} 来创建一个新的缓存，然后使用 {{domxref("Cache.add")}} 来添加一个请求资源到该缓存。</p>

<pre class="brush: js">this.addEventListener('install', function(event) {
  event.waitUntil(
    caches.open('v1').then(function(cache) {
      return cache.add('/sw-test/index.html');
    })
  );
});
</pre>

<h2 id="规范">规范</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Service Workers', '#cache', 'Cache')}}</td>
   <td>{{Spec2('Service Workers')}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="浏览器兼容性">浏览器兼容性</h2>

<div>{{CompatibilityTable}}</div>

<div id="compat-desktop">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Chrome</th>
   <th>Firefox (Gecko)</th>
   <th>Internet Explorer</th>
   <th>Opera</th>
   <th>Safari (WebKit)</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatChrome(46.0)}}</td>
   <td>{{CompatVersionUnknown}}<sup>[1]</sup></td>
   <td>{{CompatNo}}</td>
   <td>24</td>
   <td>{{CompatNo}}</td>
  </tr>
  <tr>
   <td>Require HTTPS</td>
   <td>{{CompatChrome(46.0)}}</td>
   <td>{{CompatVersionUnknown}}<sup>[1]</sup></td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
  </tr>
  <tr>
   <td><code>TypeError</code> if request is not successful</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatGeckoDesktop(47.0)}}<sup>[1]</sup></td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<div id="compat-mobile">
<table class="compat-table">
 <tbody>
  <tr>
   <th>Feature</th>
   <th>Android</th>
   <th>Android Webview</th>
   <th>Firefox Mobile (Gecko)</th>
   <th>Firefox OS</th>
   <th>IE Mobile</th>
   <th>Opera Mobile</th>
   <th>Safari Mobile</th>
   <th>Chrome for Android</th>
  </tr>
  <tr>
   <td>Basic support</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatChrome(46.0)}}</td>
  </tr>
  <tr>
   <td>Require HTTPS</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatNo}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatUnknown}}</td>
   <td>{{CompatChrome(46.0)}}</td>
  </tr>
  <tr>
   <td><code>TypeError</code> if request is not successful</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
   <td>{{CompatVersionUnknown}}</td>
  </tr>
 </tbody>
</table>
</div>

<p>[1] Service workers (and <a href="/en-US/docs/Web/API/Push_API">Push</a>) have been disabled in the <a href="https://www.mozilla.org/en-US/firefox/organizations/">Firefox 45 &amp; 52 Extended Support Releases</a> (ESR.)</p>

<h2 id="参见">参见</h2>

<ul>
 <li><a href="https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorker_API/Using_Service_Workers">Using Service Workers</a></li>
 <li>{{domxref("Cache")}}</li>
 <li>{{domxref("WorkerGlobalScope.caches")}}</li>
</ul>