HttpResponseCache在Android Lollipop中不起作用

本文介绍了HttpResponseCache在Android Lollipop中不起作用的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我已经在我的应用程序HttpResponseCache中成功使用了，但是当我的手机更新为Lollipop时，我意识到HttpResponseCache现在永远不会被命中"，总是执行网络请求.我已经确认，在Lollipop之前的Android版本中，Lollipop仍然可以正常工作. 也许这是我做错了，随着新的Android更改它已经出现了.

I've been using in my app HttpResponseCache successfully, but when my phone updated to Lollipop I realized that HttpResponseCache now never get "hit", always do the network request. I've confirmed that in Android versions pre Lollipop are still working well. Maybe it's something that I did wrong and with new Android changes it has been appeared.

有人有什么主意吗?

我的代码:

应用程序类，onCreate ...

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { try { File httpCacheDir = new File(getApplicationContext().getCacheDir() , "http"); long httpCacheSize = 10 * 1024 * 1024; HttpResponseCache.install(httpCacheDir, httpCacheSize); } catch (IOException e) { Log.i(TAG, "HTTP response cache installation failed:" + e); } } else { try { File httpCacheDir = new File(getCacheDir(), "http"); long httpCacheSize = 10 * 1024 * 1024; Class.forName("android.http.HttpResponseCache") .getMethod("install", File.class, long.class) .invoke(null, httpCacheDir, httpCacheSize); } catch (Exception e) { Log.i(TAG, "HTTP response cache installation failed:" + } }

管理请求的功能

public static InputStream fetchInputStream(String strURL, boolean forceRefresh) throws IOException { HttpURLConnection mHttpConn = null; InputStream inputStream = null; URL url = new URL(strURL); HttpResponseCache cache; try { mHttpConn = (HttpURLConnection) url.openConnection(); if (forceRefresh) { mHttpConn.addRequestProperty("Cache-Control", "no-cache"); } if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { cache = HttpResponseCache.getInstalled(); if (cache != null) { Log.i("TEST CACHE", "TEST PETICION: Req count: " + cache.getRequestCount() + ", hit count " + cache.getHitCount() + ", netWork count " + cache.getNetworkCount() + " size = " + cache.size() + " <-----------------"); } } mHttpConn.setUseCaches(true); mHttpConn.setDefaultUseCaches(true); mHttpConn.setRequestMethod("GET"); mHttpConn.setConnectTimeout(30000); mHttpConn.setReadTimeout(30000); mHttpConn.connect(); if (mHttpConn.getResponseCode() == HttpURLConnection.HTTP_OK) { inputStream = mHttpConn.getInputStream(); } } catch (IOException ex) { Log.e("NetworkConnectionManager InputStream", "Exception opening [" + strURL + "] ->", ex); mHttpConn.disconnect(); throw ex; } return inputStream; }

每次请求后

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) { HttpResponseCache cache = HttpResponseCache.getInstalled(); if (cache != null) { cache.flush(); } }

示例请求标头:

• 缓存控制→max-age = 300
• 连接→保持活动状态
• 内容编码→gzip
• 内容类型→application/json; charset = utf-8
• 日期→星期三，2015年4月8日格林尼治标准时间
• Expires→周三，2015年4月8日格林尼治标准时间
• 最后修改→2015年4月8日，星期三，格林尼治标准时间
• 服务器→nginx
• 传输编码→分块
• 变化→接受编码
• X缓存→MISS

• Cache-Control → max-age=300
• Connection → keep-alive
• Content-Encoding → gzip
• Content-Type → application/json; charset=utf-8
• Date → Wed, 08 Apr 2015 12:37:35 GMT
• Expires → Wed, 08 Apr 2015 12:42:35 GMT
• Last-Modified → Wed, 08 Apr 2015 12:37:35 GMT
• Server → nginx
• Transfer-Encoding → chunked
• Vary → Accept-Encoding
• X-Cached → MISS

推荐答案

在经历了几天这个问题之后，我遇到了这个问题.再次在棉花糖中固定.

After having this problem for days I ran into this issue. It is fixed again in Marshmallow.

这是棒棒糖中的一个错误，其中Vary-> Accept-Encoding标头破坏了缓存，因为默认情况下会填充Accept-Encoding而不将其写掉.

It is a bug in lollipop where the Vary - > Accept-Encoding header breaks the cache because Accept-Encoding gets filled in by default but not written away.

这里是问题的链接:

code.google/p/android/issues/detail?id = 162475

解决方法是显式设置Accept-Encoding:

The fix is to set the Accept-Encoding explicitly:

接受编码-> gzip

Accept-Encoding -> gzip

或

接受编码->身份

在阅读方面，您必须将其添加到输入流的阅读中:

On the reading side you have to add this to the reading of the input stream:

String encoding = urlConnection.getHeaderField("Content-Encoding"); boolean gzipped = encoding!=null && encoding.toLowerCase().contains("gzip"); Inputstream inputStream; if(gzipped) inputStream = new GZIPInputStream(urlConnection.getInputStream()); else inputstream = urlConnection.getInputStream();