在我的缓存机制中将请求添加到RequestQueue并尝试从服务器获取数据后，我的缓存方法从服务器返回多个重复结果返回json字符串
RequestQueue queue = Volley.newRequestQueue(this);
String url = Globals.getHostAddress() + "/get_latest_video";
items.clear();
CacheRequest cacheRequest = new CacheRequest(0, url, new Response.Listener<NetworkResponse>() {
@Override
public void onResponse(NetworkResponse response) {
try {
final String jsonString = new String(response.data,
HttpHeaderParser.parseCharset(response.headers));
Log.e("allVideos", jsonString);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
// Add the request to the RequestQueue.
queue.add(cacheRequest);
服务器返回此结果：
{"id":12,"channel_id":7,"category_id":8}
缓存机制返回：
{"id":12,"channel_id":7,"category_id":8},{"id":12,"channel_id":7,"category_id":8}
缓存数据和使用数据的代码问题是什么？
CacheRequest类内容：
public class CacheRequest extends Request<NetworkResponse> {
private final Response.Listener<NetworkResponse> mListener;
private final Response.ErrorListener mErrorListener;
public CacheRequest(int method, String url, Response.Listener<NetworkResponse> listener, Response.ErrorListener errorListener) {
super(method, url, errorListener);
this.mListener = listener;
this.mErrorListener = errorListener;
}
@Override
protected Response<NetworkResponse> parseNetworkResponse(NetworkResponse response) {
Cache.Entry cacheEntry = HttpHeaderParser.parseCacheHeaders(response);
if (cacheEntry == null) {
cacheEntry = new Cache.Entry();
}
final long cacheHitButRefreshed = 3 * 60 * 1000; // in 3 minutes cache will be hit, but also refreshed on background
final long cacheExpired = 24 * 60 * 60 * 1000; // in 24 hours this cache entry expires completely
long now = System.currentTimeMillis();
final long softExpire = now + cacheHitButRefreshed;
final long ttl = now + cacheExpired;
cacheEntry.data = response.data;
cacheEntry.softTtl = softExpire;
cacheEntry.ttl = ttl;
String headerValue;
headerValue = response.headers.get("Date");
if (headerValue != null) {
cacheEntry.serverDate = HttpHeaderParser.parseDateAsEpoch(headerValue);
}
headerValue = response.headers.get("Last-Modified");
if (headerValue != null) {
cacheEntry.lastModified = HttpHeaderParser.parseDateAsEpoch(headerValue);
}
cacheEntry.responseHeaders = response.headers;
return Response.success(response, cacheEntry);
}
@Override
protected void deliverResponse(NetworkResponse response) {
mListener.onResponse(response);
}
@Override
protected VolleyError parseNetworkError(VolleyError volleyError) {
return super.parseNetworkError(volleyError);
}
@Override
public void deliverError(VolleyError error) {
mErrorListener.onErrorResponse(error);
}
}
更新的帖子：
public class ActivityBootstrap extends Activity implements AdapterView.OnItemClickListener {
@InjectView(R.id.drawer_list)
ListView drawer_list;
@InjectView(R.id.drawer_layout)
DrawerLayout drawer_layout;
@InjectView(R.id.listView)
AsymmetricGridView listView;
private List<DrawerItem> drawer_items = new ArrayList<DrawerItem>();
private List<VideoItems> items = new ArrayList<>();
private DrawerAdatper drawer_adatper = null;
private boolean mDrawerState = false;
private VideoAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.inject(this);
RequestQueue queue = Volley.newRequestQueue(this);
String url = Globals.getHostAddress() + "/get_latest_video";
items.clear();
CacheRequest cacheRequest = new CacheRequest(0, url, new Response.Listener<NetworkResponse>() {
@Override
public void onResponse(NetworkResponse response) {
try {
final String jsonString = new String(response.data,
HttpHeaderParser.parseCharset(response.headers));
Log.e("allVideos", jsonString);
JSONArray jsonArray = new JSONArray(jsonString);
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject video_single_item = jsonArray.getJSONObject(i);
int video_id = video_single_item.getInt("id");
String video_thumbnail = video_single_item.getString("thumbnail");
int colSpan = Math.random() < 0.2f ? 2 : 1;
int rowSpan = colSpan;
VideoItems item = new VideoItems(colSpan, rowSpan, video_thumbnail,video_id);
items.add(item);
}
setUpListView(items);
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
});
// Add the request to the RequestQueue.
queue.add(cacheRequest);
}
private void setUpListView(List video_array_items) {
final List<AsymmetricItem> items = new ArrayList<>();
adapter = new VideoListAdapter(this, video_array_items);
AsymmetricGridViewAdapter asymmetricAdapter =
new AsymmetricGridViewAdapter<>(this, listView, adapter);
listView.setAdapter(asymmetricAdapter);
listView.setRequestedColumnCount(3);
listView.setAdapter(getNewAdapter());
listView.setOnItemClickListener(this);
listView.setAllowReordering(true);
listView.isAllowReordering();
}
private AsymmetricGridViewAdapter<?> getNewAdapter() {
return new AsymmetricGridViewAdapter<>(this, listView, adapter);
}
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
int video_position = items.get(position).getVideo_id();
Intent intent = new Intent(ActivityBootstrap.this, ActivitySHowVideoDetaile.class);
intent.putExtra("video_id", video_position);
startActivity(intent);
}
}
更新后的帖子2）
Log.e("allVideos", jsonString);的结果是：
10-28 09:51:46.016 17872-17872/pishguy.ir.asrebidree E/allVideos: [{"id":12,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"},{"id":10,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"}]
10-28 09:51:47.249 17872-17872/pishguy.ir.asrebidree E/allVideos: [{"id":12,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"},{"id":10,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"}]
服务器响应的结果我用浏览器测试它：
[{"id":12,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"},{"id":10,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"}]
不幸的是，此重复结果是随机的（并非每次都重复）
更新3:
10-28 13:14:52.322 16129-16129/pishguy.ir.asrebidree E/Test: onCreate called
10-28 13:14:52.513 16129-16129/pishguy.ir.asrebidree E/allVideos: [{"id":12,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"},{"id":10,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"}]
10-28 13:14:53.206 16129-16129/pishguy.ir.asrebidree E/allVideos: [{"id":12,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"},{"id":10,"thumbnail":"1445615983c92d10f1f3ee907150be1fdb8184ca893178682-360p__19106.png"}]
因为我评论了太多行，我无法将"重复行为"作为您当前的问题重新生成，所以我在这里发布了我的答案，希望这能有所帮助！
在CacheDispatcher类中，您会发现以下内容：
if (!entry.refreshNeeded()) {
// Completely unexpired cache hit. Just deliver the response.
mDelivery.postResponse(request, response);
} else {
// Soft-expired cache hit. We can deliver the cached response,
// but we need to also send the request to the network for
// refreshing.
request.addMarker("cache-hit-refresh-needed");
request.setCacheEntry(entry);
// Mark the response as intermediate.
response.intermediate = true;
// Post the intermediate response back to the user and have
// the delivery then forward the request along to the network.
mDelivery.postResponse(request, response, new Runnable() {
@Override
public void run() {
try {
mNetworkQueue.put(request);
} catch (InterruptedException e) {
// Not much we can do about this.
}
}
});
}
IMO，可能是softTtl导致了这种复制行为。
我建议您使用以下行为您的请求设置RetryPolicy：
cacheRequest.setRetryPolicy(new DefaultRetryPolicy(DefaultRetryPolicy.DEFAULT_TIMEOUT_MS * 2, 0, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT));
// Add the request to the RequestQueue.
queue.add(cacheRequest);