问题描述
您好我想使用的Htt的presponseCache在安卓4.文档介绍了不说清楚有关如何安装的缓存，但我在如何缓存图片完全丧失从net.Earlier我下载是使用DiskLruCache对其进行缓存。会有人指出我对工作code一些例子，其中的Htt presponseCache已被使用。
编辑： - 谁能告诉我什么，我做错了什么： -
MainActivity.java
公共无效的onCreate（包savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.activity_main）;
最终长httpCacheSize = 10 * 1024 * 1024; // 10 MIB
最终文件httpCacheDir =新的文件（getCacheDir（），HTTP）;
尝试 {
的Class.forName（android.net.http.Htt presponseCache）
.getMethod（安装，File.class，long.class）
.invoke（NULL，httpCacheDir，httpCacheSize）;
Log.v（TAG，缓存设置）;
}赶上（例外HTT presponseCacheNotAvailable）{
Log.v（TAG，android.net.http.Htt presponseCache不可用，可能是因为我们正在运行在Android上的pre-ICS版本。使用com.integralblue.htt presponsecache。 HttpHtt presponseCache）。
尝试{
com.integralblue.htt presponsecache.Htt presponseCache.install（httpCacheDir，httpCacheSize）;
}赶上（例外五）{
Log.v（TAG，无法设置com.integralblue.htt presponsecache.Htt presponseCache）;
}
}
TheMainListFrag GF =（TheMainListFrag）getSupportFragmentManager（）findFragmentByTag（thelistfrags）。
如果（GF == NULL）{
GF = TheMainListFrag.newInstance（）;
FragmentTransaction英尺= getSupportFragmentManager（）的BeginTransaction（）。
ft.replace（R.id.thelefty，广发，thelistfrags）;
ft.commit（）;
}
}
然后在TheMainListFrag的装载机，我做了如下： -
公开的ArrayList＆LT; HashMap的＆LT;字符串，字符串＆GT;＆GT; loadInBackground（）{
字符串datafromServer = NULL;
ArrayList的＆LT; HashMap的＆LT;字符串，字符串＆GT;＆GT;人=新的ArrayList＆LT; HashMap的＆LT;字符串，字符串＆GT;＆GT;（）;
尝试 {
字符串URL =someurl;
HttpURLConnection的的URLConnection =（HttpURLConnection类）新的网址（URL）.openConnection（）;
urlConnection.setRequestProperty（接受，应用/ JSON）;
InputStream的是=新的BufferedInputStream（urlConnection.getInputStream（））;
的BufferedReader BR =新的BufferedReader（新InputStreamReader的（是））;
StringBuilder的SB =新的StringBuilder（）;
串线= NULL;
而（（行= br.readLine（））！= NULL）{
sb.append（线）;
}
datafromServer = sb.toString（）;
Log.v（fromthread，datafromServer）;
// 等等
//等等
}赶上（MalformedURLException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}赶上（IOException异常E）{
// TODO自动生成的catch块
e.printStackTrace（）;
}赶上（例外五）{
Log.v（fromthread，e.getClass（）+ - + e.getMessage（））;
}
返回人;
}
当我连接到互联网，它工作正常，并在目录中的HTTP-上述命名的缓存目录，我可以看到文件了。但是，当我没有连接到互联网，数据拒绝加载。
当我从网上载入图像，我看到命名为.tmp文件的缓存文件，我相信被称为肮脏按DiskLruCache。
请让我知道，如果有任何其他的信息，你要我提供
这部分的强制缓存响应上的：
尝试{
connection.addRequestProperty（缓存控制，只有-IF-缓存）;
InputStream的缓存= connection.getInputStream（）;
//资源被缓存！展示下
}赶上（FileNotFoundException异常E）{
//资源没有缓存
}
INT maxStale = 60 * 60 * 24 * 28; //容忍4周陈旧
connection.addRequestProperty（缓存控制，MAX-陈旧=+ maxStale）;
Hi I am trying to use the HttpResponseCache introduced in Android 4.The docs do talk clearly about how to install the cache but I am at a complete loss on how to cache Images downloaded from the net.Earlier I was using the DiskLruCache to cache them. Would anyone point me towards some examples of working code where HttpResponseCache has been used..
Edit:- Can someone tell me what I am doing wrong here:-
MainActivity.java
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final long httpCacheSize = 10 * 1024 * 1024; // 10 MiB
final File httpCacheDir = new File(getCacheDir(), "http");
try {
Class.forName("android.net.http.HttpResponseCache")
.getMethod("install", File.class, long.class)
.invoke(null, httpCacheDir, httpCacheSize);
Log.v(TAG,"cache set up");
} catch (Exception httpResponseCacheNotAvailable) {
Log.v(TAG, "android.net.http.HttpResponseCache not available, probably because we're running on a pre-ICS version of Android. Using com.integralblue.httpresponsecache.HttpHttpResponseCache.");
try{
com.integralblue.httpresponsecache.HttpResponseCache.install(httpCacheDir, httpCacheSize);
}catch(Exception e){
Log.v(TAG, "Failed to set up com.integralblue.httpresponsecache.HttpResponseCache");
}
}
TheMainListFrag gf=(TheMainListFrag) getSupportFragmentManager().findFragmentByTag("thelistfrags");
if(gf==null){
gf=TheMainListFrag.newInstance();
FragmentTransaction ft=getSupportFragmentManager().beginTransaction();
ft.replace(R.id.thelefty, gf,"thelistfrags");
ft.commit();
}
}
Then in the loader of TheMainListFrag, I do the below:-
public ArrayList<HashMap<String,String>> loadInBackground() {
String datafromServer = null;
ArrayList<HashMap<String,String>> al = new ArrayList<HashMap<String,String>>();
try {
String url = "someurl";
HttpURLConnection urlConnection = (HttpURLConnection) new URL(url).openConnection();
urlConnection.setRequestProperty("Accept", "application/json");
InputStream is = new BufferedInputStream(urlConnection.getInputStream());
BufferedReader br = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = br.readLine()) != null) {
sb.append(line);
}
datafromServer=sb.toString();
Log.v("fromthread",datafromServer);
// etc
//etc
} catch (MalformedURLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
Log.v("fromthread", e.getClass() + "--" + e.getMessage());
}
return al;
}
When i am connected to internet, it works fine, and in the directory http-the cache directory named above, i can see the files too. But when I am not connected to the internet, the data refuses to load.
When i load images from the net, i see the cache files named as .tmp , which i believe are termed as dirty as per DiskLruCache.
Please let me know if there is any other info that you want me to provide
From the section Force a Cache Response on the HttpResponseCache documentation:
try {
connection.addRequestProperty("Cache-Control", "only-if-cached");
InputStream cached = connection.getInputStream();
// the resource was cached! show it
} catch (FileNotFoundException e) {
// the resource was not cached
}
int maxStale = 60 * 60 * 24 * 28; // tolerate 4-weeks stale
connection.addRequestProperty("Cache-Control", "max-stale=" + maxStale);
这篇关于需要的Htt presponseCache在Android的一个例子的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！