[英]How to put JSONArray of object in JSONObject inside servlet
[英]How to Parsing Android JsonObject and storing it after storing the Object with JsonArray inside RecyclerView
我试图解析如下的Json
:
{
"status": "ok",
"feed": {
"title": "title1",
"link": "http://www.link/",
"author": "",
"description": "desc",
"image": ""
},
"items": [
{
"title": "something",
"link": "something",
"guid": "something",
"pubDate": "date",
"categories": [],
"author": "",
"thumbnail": "",
"description": null,
"content": null
},
...
...
我从response
得到了预期的结果,但这不是重点。这是我所做的:
try {
JSONObject response = new JSONObject(result);
JSONObject feed_object = response.getJSONObject("feed");
PostItems item = new PostItems();
item.setAuthor(feed_object.getString("title"));
JSONArray items_arr = response.getJSONArray("items");
for (int i = 0; i < items_arr.length(); i++) {
JSONObject post = items_arr.getJSONObject(i);
item.setTitle(post.getString("title"));
item.setDate(post.getString("pubDate")); // As expected results
feedItem.add(item);
}
}
关键是,如果我像上面代码那样存储(第一个object
),则RecyclerView
会显示项目,但没有在项目中设置正确的title
和date
。
如果我将它存储在数组中,然后在数组内部(对于array
)和array
外部设置一个,它只会显示如下错误:
java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.String.length()' on a null object reference
at java.io.StringReader.<init>(StringReader.java:47)
at android.text.HtmlToSpannedConverter.convert(Html.java:449)
at android.text.Html.fromHtml(Html.java:136)
at android.text.Html.fromHtml(Html.java:99)
at client.com.news.RecyclerViews.MainSanjeshRecyclerView.MyRecyclerAdapter.onBindViewHolder(MyRecyclerAdapter.java:34)
at client.com.news.RecyclerViews.MainSanjeshRecyclerView.MyRecyclerAdapter.onBindViewHolder(MyRecyclerAdapter.java:14)
at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:5465)
at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:5498)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4735)
at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:4611)
at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:1988)
at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1384)
at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1347)
at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:574)
at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3026)
at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:2903)
at android.support.v7.widget.RecyclerView.onLayout(RecyclerView.java:3277)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.support.v4.widget.SwipeRefreshLayout.onLayout(SwipeRefreshLayout.java:596)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.support.v4.view.ViewPager.onLayout(ViewPager.java:1684)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.support.design.widget.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:122)
at android.support.design.widget.ViewOffsetBehavior.onLayoutChild(ViewOffsetBehavior.java:42)
at android.support.design.widget.AppBarLayout$ScrollingViewBehavior.onLayoutChild(AppBarLayout.java:1139)
at android.support.design.widget.CoordinatorLayout.onLayout(CoordinatorLayout.java:810)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1743)
at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1586)
at android.widget.LinearLayout.onLayout(LinearLayout.java:1495)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.widget.FrameLayout.layoutChildren(FrameLayout.java:336)
at android.widget.FrameLayout.onLayout(FrameLayout.java:273)
at com.android.internal.policy.PhoneWindow$DecorView.onLayout(PhoneWindow.java:2678)
at android.view.View.layout(View.java:16630)
at android.view.ViewGroup.layout(ViewGroup.java:5437)
at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:2171)
at android.vi
第二次尝试:
try {
JSONObject response = new JSONObject(result);
JSONObject feed_object = response.getJSONObject("feed");
PostItems item = new PostItems();
item.setAuthor(feed_object.getString("title"));
JSONArray items_arr = response.getJSONArray("items");
for (int i = 0; i < items_arr.length(); i++) {
JSONObject post = items_arr.getJSONObject(i);
PostItems item2 = new PostItems();
item2.setTitle(post.getString("title"));
item2.setDate(post.getString("pubDate"));
feedItem.add(item2);
}
feedItem.add(item);
}
实际上,我已经尝试了任何你可以想象的方法,并在 stackoverflow 上看到了任何问题,但我找不到类似这样的问题,但是有一次,只显示一项没有来自对象的正确数据,有一次没有显示正确的数据从那个Array
。
任何帮助都会很棒。
您正在尝试在每个项目中使用getAuthor()
,但显然它只为ArrayList
中的一个(第一个)项目设置。 当它没有任何值时,它返回null
,导致NullPointerException
。 也应该在每次迭代时创建新对象。
只是移动
PostItems item = new PostItems();
item.setAuthor(feed_object.getString("title"));
在for
循环内。
编辑
try {
JSONObject response = new JSONObject(result);
JSONObject feed_object = response.getJSONObject("feed");
JSONArray items_arr = response.getJSONArray("items");
for (int i = 0; i < items_arr.length(); i++) {
JSONObject post = items_arr.getJSONObject(i);
PostItems item = new PostItems();
item.setAuthor(feed_object.getString("title")); // being fetched from top node
item.setTitle(post.getString("title")); // being fetched from array
item.setDate(post.getString("pubDate")); // being fetched from array
feedItem.add(item);
}
}
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