HttpResponseCache 'PUT‘请求方法未缓存

Question

我为服务器请求使用HttpUrlConnection，为PUT请求使用HttpResponseCache 缓存response.But响应没有缓存，有人知道原因吗?缓存只用于POST和GET方法吗？

Answer 1

某些HTTP方法必须使缓存使实体无效。这可以是Request-URI引用的实体，也可以是Location或Content-Location标头(如果存在)。这些方法包括：

• PUT
• DELETE
• POST

(http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html)

Answer 2

来自HttpResponseCache源代码的注释表明未实现对非GET的缓存：

https://android.googlesource.com/platform/libcore/+/cff1616012dc0d56c2da9af2b9b1183e76c7e044/luni/src/main/java/libcore/net/http/HttpResponseCache.java

    /*
     * Don't cache non-GET responses. We're technically allowed to cache
     * HEAD requests and some POST requests, but the complexity of doing
     * so is high and the benefit is low.
     */
   return null;