这就是我所拥有的，但孩子的数量永远不会打印出来。我正在获取原始JSON，然后创建一个JSONArray，访问第二个成员的子节点。我在这里错过了什么？我有类似的代码可以完美地工作，只有区别在于JSON，它不是以数组
开头JSON输入：
[
{
"kind":"Listing",
"data":{
"modhash":"",
"children":[
{
"kind":"t3",
"data":{
"domain":"",
"banned_by":null,
"media_embed":{
},
"subreddit":"",
"selftext_html":"",
"selftext":"",
"likes":null,
"secure_media":null,
"link_flair_text":null,
"id":"1zeek5",
"secure_media_embed":{},
"clicked":false,
"stickied":false,
"author":"xVictoryy",
"media":null,
"score":1,
"approved_by":null,
"over_18":false,
"hidden":false,
"thumbnail":"",
"subreddit_id":"t5_2sdpm",
"edited":false,
"link_flair_css_class":null,
"author_flair_css_class":null,
"downs":0,
"saved":false,
"is_self":true,
"permalink":"",
"name":"t3_1zeek5",
"created":1393843471.0,
"url":"",
"author_flair_text":null,
"title":"Seeking advice.",
"created_utc":1393814671.0,
"ups":1,
"num_comments":3,
"visited":false,
"num_reports":null,
"distinguished":null
}
}
],
"after":null,
"before":null
}
},
{
"kind":"Listing",
"data":{
"modhash":"",
"children":[
{
"kind":"t1",
"data":{
"subreddit_id":"t5_2sdpm",
"banned_by":null,
"subreddit":"",
"likes":null,
"replies":{
"kind":"Listing",
"data":{
"modhash":"",
"children":[
{
"kind":"t1",
"data":{
"subreddit_id":"t5_2sdpm",
"banned_by":null,
"subreddit":"cscareerquestions",
"likes":null,
"replies":"",
"saved":false,
"id":"cfsxjqn",
"gilded":0,
"author":"xVictoryy",
"parent_id":"t1_cfsx26m",
"approved_by":null,
"body":"",
"edited":false,
"author_flair_css_class":null,
"downs":0,
"body_html":"",
"link_id":"t3_1zeek5",
"score_hidden":false,
"name":"t1_cfsxjqn",
"created":1393845230.0,
"author_flair_text":null,
"created_utc":1393816430.0,
"distinguished":null,
"num_reports":null,
"ups":1
}
}
],
"after":null,
"before":null
}
},
"saved":false,
"id":"cfsx26m",
"gilded":0,
"author":"dauphic",
"parent_id":"t3_1zeek5",
"approved_by":null,
"body":"A lot of schools don't expect high school Calculus.",
"edited":false,
"author_flair_css_class":"",
"downs":0,
"body_html":"",
"link_id":"t3_1zeek5",
"score_hidden":false,
"name":"t1_cfsx26m",
"created":1393844079.0,
"author_flair_text":"Software Engineer",
"created_utc":1393815279.0,
"distinguished":null,
"num_reports":null,
"ups":1
}
},
{
"kind":"t1",
"data":{
"subreddit_id":"t5_2sdpm",
"banned_by":null,
"subreddit":"cscareerquestions",
"likes":null,
"replies":"",
"saved":false,
"id":"cft3lbj",
"gilded":0,
"author":"I_EAT_GUSHERS",
"parent_id":"t3_1zeek5",
"approved_by":null,
"body":"",
"edited":false,
"author_flair_css_class":"",
"downs":0,
"body_html":"",
"link_id":"t3_1zeek5",
"score_hidden":false,
"name":"t1_cft3lbj",
"created":1393864015.0,
"author_flair_text":"Looking for internship",
"created_utc":1393835215.0,
"distinguished":null,
"num_reports":null,
"ups":1
}
}
],
"after":null,
"before":null
}
}
]
我的代码：
List<Comment> fetchComments() {
Log.d("running", "attempting fetch...");
String raw = RemoteData.readContents(url);
List<Comment> list = new ArrayList<Comment>();
try {
JSONObject data = new JSONArray(raw).getJSONObject(1);
JSONArray children = data.getJSONArray("children");
Log.d("running", "comments: " + children.length());
}
} catch (Exception e) {
Log.e("fetchComments()", e.toString());
}
return list;
}
public static String readContents(String url){
HttpURLConnection hcon=getConnection(url);
if(hcon==null) return null;
try{
StringBuffer sb=new StringBuffer(8192);
String tmp="";
BufferedReader br=new BufferedReader(
new InputStreamReader(
hcon.getInputStream()
)
);
while((tmp=br.readLine())!=null)
sb.append(tmp).append("\n");
br.close();
return sb.toString();
}catch(IOException e){
Log.d("READ FAILED", e.toString());
return null;
}
}
答案 0 :(得分：0)
您没有进入数据对象...您的列表项中只有“kind”和“data”标签，因此首先进入“data”标签然后获取“children”。试试这样：
List<Comment> fetchComments() {
Log.d("running", "attempting fetch...");
String raw = RemoteData.readContents(url);
List<Comment> list = new ArrayList<Comment>();
try {
JSONObject data = new JSONArray(raw).getJSONObject(1);
JSONArray children = data.getJSONObject("data").getJSONArray("children");
Log.d("running", "comments: " + children.length());
}
} catch (Exception e) {
Log.e("fetchComments()", e.toString());
}
return list;
}
答案 1 :(得分：0)
您的JSON数组包含具有字段“data”的对象，该字段包含一个包含字段“children”的对象。
你在做：
JSONObject data = new JSONArray(raw).getJSONObject(1);
JSONArray children = data.getJSONArray("children");
您错过了data字段。
JSONObject obj = new JSONArray(raw).getJSONObject(1);
JSONArray children = obj.getJSONObject("data").getJSONArray("children");