blocks|key|889467|text|实例数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|889468|Object.getClass().getName()|889469|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

instanceof

Object.getClass().getName()

blocks|key|889529|text|我找到了更好的方法来确定：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|889530|String+data+=+"{+...+}";
Object+json+=+new+JSONTokener(data).nextValue();
if+(json+instanceof+JSONObject)
++//you+have+an+object
else+if+(json+instanceof+JSONArray)
++//you+have+an+array|code-block|syntax|javascript|889531|记号赋予器能够返回更多类型：http://developer.android.com/reference/org/json/JSONTokener.html#nextValue()|offset|length|889532|entityMap|0|LINK|mutability|MUTABLE|url|http://developer.android.com/reference/org/json/JSONTokener.html#nextValue^0|0|0|E|22|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@$I|V|J|W|1|X]]|A|$]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|R]]]]

I found better way to determine:

<pre><code>String data = "{ ... }";
Object json = new JSONTokener(data).nextValue();
if (json instanceof JSONObject)
 //you have an object
else if (json instanceof JSONArray)
 //you have an array
</code></pre>

tokenizer is able to return more types: <a href="http://developer.android.com/reference/org/json/JSONTokener.html#nextValue">http://developer.android.com/reference/org/json/JSONTokener.html#nextValue</a>()

blocks|key|889633|text|我的方法将是对此的完全抽象。也许有人会觉得这很有用。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|889634|import+java.lang.reflect.Field;
import+java.util.ArrayList;
import+java.util.Collection;
import+java.util.Map;

import+org.json.JSONArray;
import+org.json.JSONException;
import+org.json.JSONObject;

public+class+SimpleJSONObject+extends+JSONObject+{


++++private+static+final+String+FIELDNAME_NAME_VALUE_PAIRS+=+"nameValuePairs";


++++public+SimpleJSONObject(String+string)+throws+JSONException+{
++++++++super(string);
++++}


++++public+SimpleJSONObject(JSONObject+jsonObject)+throws+JSONException+{
++++++++super(jsonObject.toString());
++++}


++++@Override
++++public+JSONObject+getJSONObject(String+name)+throws+JSONException+{

++++++++final+JSONObject+jsonObject+=+super.getJSONObject(name);

++++++++return+new+SimpleJSONObject(jsonObject.toString());
++++}


++++@Override
++++public+JSONArray+getJSONArray(String+name)+throws+JSONException+{

++++++++JSONArray+jsonArray+=+null;

++++++++try+{

++++++++++++final+Map<String,+Object>+map+=+this.getKeyValueMap();

++++++++++++final+Object+value+=+map.get(name);

++++++++++++jsonArray+=+this.evaluateJSONArray(name,+value);

++++++++}+catch+(Exception+e)+{

++++++++++++throw+new+RuntimeException(e);

++++++++}

++++++++return+jsonArray;
++++}


++++private+JSONArray+evaluateJSONArray(String+name,+final+Object+value)+throws+JSONException+{

++++++++JSONArray+jsonArray+=+null;

++++++++if+(value+instanceof+JSONArray)+{

++++++++++++jsonArray+=+this.castToJSONArray(value);

++++++++}+else+if+(value+instanceof+JSONObject)+{

++++++++++++jsonArray+=+this.createCollectionWithOneElement(value);

++++++++}+else+{

++++++++++++jsonArray+=+super.getJSONArray(name);

++++++++}
++++++++return+jsonArray;
++++}


++++private+JSONArray+createCollectionWithOneElement(final+Object+value)+{

++++++++final+Collection<Object>+collection+=+new+ArrayList<Object>();
++++++++collection.add(value);

++++++++return+(JSONArray)+new+JSONArray(collection);
++++}


++++private+JSONArray+castToJSONArray(final+Object+value)+{
++++++++return+(JSONArray)+value;
++++}


++++private+Map<String,+Object>+getKeyValueMap()+throws+NoSuchFieldException,+IllegalAccessException+{

++++++++final+Field+declaredField+=+JSONObject.class.getDeclaredField(FIELDNAME_NAME_VALUE_PAIRS);
++++++++declaredField.setAccessible(true);

++++++++@SuppressWarnings("unchecked")
++++++++final+Map<String,+Object>+map+=+(Map<String,+Object>)+declaredField.get(this);

++++++++return+map;
++++}


}|code-block|syntax|javascript|889635|现在永远摆脱这种行为。|889636|...
JSONObject+simpleJSONObject+=+new+SimpleJSONObject(jsonObject);
...|889637|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

My approach would be a total abstraction from this. Maybe someone finds this useful...

<pre><code>import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class SimpleJSONObject extends JSONObject {


 private static final String FIELDNAME_NAME_VALUE_PAIRS = "nameValuePairs";


 public SimpleJSONObject(String string) throws JSONException {
 super(string);
 }


 public SimpleJSONObject(JSONObject jsonObject) throws JSONException {
 super(jsonObject.toString());
 }


 @Override
 public JSONObject getJSONObject(String name) throws JSONException {

 final JSONObject jsonObject = super.getJSONObject(name);

 return new SimpleJSONObject(jsonObject.toString());
 }


 @Override
 public JSONArray getJSONArray(String name) throws JSONException {

 JSONArray jsonArray = null;

 try {

 final Map&lt;String, Object&gt; map = this.getKeyValueMap();

 final Object value = map.get(name);

 jsonArray = this.evaluateJSONArray(name, value);

 } catch (Exception e) {

 throw new RuntimeException(e);

 }

 return jsonArray;
 }


 private JSONArray evaluateJSONArray(String name, final Object value) throws JSONException {

 JSONArray jsonArray = null;

 if (value instanceof JSONArray) {

 jsonArray = this.castToJSONArray(value);

 } else if (value instanceof JSONObject) {

 jsonArray = this.createCollectionWithOneElement(value);

 } else {

 jsonArray = super.getJSONArray(name);

 }
 return jsonArray;
 }


 private JSONArray createCollectionWithOneElement(final Object value) {

 final Collection&lt;Object&gt; collection = new ArrayList&lt;Object&gt;();
 collection.add(value);

 return (JSONArray) new JSONArray(collection);
 }


 private JSONArray castToJSONArray(final Object value) {
 return (JSONArray) value;
 }


 private Map&lt;String, Object&gt; getKeyValueMap() throws NoSuchFieldException, IllegalAccessException {

 final Field declaredField = JSONObject.class.getDeclaredField(FIELDNAME_NAME_VALUE_PAIRS);
 declaredField.setAccessible(true);

 @SuppressWarnings("unchecked")
 final Map&lt;String, Object&gt; map = (Map&lt;String, Object&gt;) declaredField.get(this);

 return map;
 }


}
</code></pre>

And now get rid of this behaviour forever...

<pre><code>...
JSONObject simpleJSONObject = new SimpleJSONObject(jsonObject);
...
</code></pre>

blocks|key|889688|text|这是我在Android上使用的简单解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|889689|JSONObject+json+=+new+JSONObject(jsonString);

if+(json.has("data"))+{

++++JSONObject+dataObject+=+json.optJSONObject("data");

++++if+(dataObject+!=+null)+{

++++++++//Do+things+with+object.

++++}+else+{

++++++++JSONArray+array+=+json.optJSONArray("data");

++++++++//Do+things+with+array
++++}
}+else+{
++++//+Do+nothing+or+throw+exception+if+"data"+is+a+mandatory+field
}|code-block|syntax|javascript|889690|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is the simple solution I'm using on Android:

<pre><code>JSONObject json = new JSONObject(jsonString);

if (json.has("data")) {

 JSONObject dataObject = json.optJSONObject("data");

 if (dataObject != null) {

 //Do things with object.

 } else {

 JSONArray array = json.optJSONArray("data");

 //Do things with array
 }
} else {
 // Do nothing or throw exception if "data" is a mandatory field
}
</code></pre>

blocks|key|889755|text|对于那些在JavaScript中处理这个问题的人，下面的方法为我做了这项工作(不确定它有多有效)。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|889756|if(object.length+!=+undefined)+{
+++console.log('Array+found.+Length+is+:+'+%2B+object.length);+
}+else+{
+console.log('Object+found.');+
}|code-block|syntax|javascript|889757|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

For those tackling this issue in JavaScript, the following did the job for me (not sure how efficient it is). 

<pre><code>if(object.length != undefined) {
 console.log('Array found. Length is : ' + object.length); 
} else {
 console.log('Object found.'); 
}
</code></pre>

blocks|key|673042|text|下面是一种更基本的方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|673043|JsonArray本质上是一个List|offset|length|style|CODE|673044|JsonObject本质上是一个Map|673045|if+(object+instanceof+Map){
++++JSONObject+jsonObject+=+new+JSONObject();
++++jsonObject.putAll((Map)object);
++++...
++++...
}
else+if+(object+instanceof+List){
++++JSONArray+jsonArray+=+new+JSONArray();
++++jsonArray.addAll((List)object);
++++...
++++...
}|code-block|syntax|javascript|673046|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/7/docs/api/java/util/List.html|1|http://docs.oracle.com/javase/7/docs/api/java/util/Map.html^0|0|0|9|F|4|0|0|0|A|G|3|1|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@$D|10|E|11|F|G]]|9|@$D|12|E|13|1|14]]|A|$]]|$1|H|3|I|5|6|7|15|8|@$D|16|E|17|F|G]]|9|@$D|18|E|19|1|1A]]|A|$]]|$1|J|3|K|5|L|7|1B|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|1C|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]|W|$5|R|S|T|A|$U|X]]]]

A more fundamental way of doing this is the following.

<code>JsonArray</code> is inherently a <a href="http://docs.oracle.com/javase/7/docs/api/java/util/List.html" rel="nofollow">List</a>

<code>JsonObject</code> is inherently a <a href="http://docs.oracle.com/javase/7/docs/api/java/util/Map.html" rel="nofollow">Map</a>

<pre><code>if (object instanceof Map){
 JSONObject jsonObject = new JSONObject();
 jsonObject.putAll((Map)object);
 ...
 ...
}
else if (object instanceof List){
 JSONArray jsonArray = new JSONArray();
 jsonArray.addAll((List)object);
 ...
 ...
}
</code></pre>

blocks|key|673109|text|呈现另一种方式：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|673110|if(server_response.trim().charAt(0)+==+'[')+{
++++Log.e("Response+is+:+"+,+"JSONArray");
}+else+if(server_response.trim().charAt(0)+==+'{')+{
++++Log.e("Response+is+:+"+,+"JSONObject");
}|code-block|syntax|javascript|673111|这里的server_response是来自服务器的响应字符串|offset|length|style|CODE|673112|entityMap^0|0|0|3|F|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Presenting an another way :

<pre><code>if(server_response.trim().charAt(0) == '[') {
 Log.e("Response is : " , "JSONArray");
} else if(server_response.trim().charAt(0) == '{') {
 Log.e("Response is : " , "JSONObject");
}
</code></pre>

Here <code>server_response</code> is a response String coming from server

blocks|key|673176|text|JsonNode+jsonNode=mapper.readTree(patchBody);|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|673177|jsonNode有两种方法：|unstyled|673178|isObject()；|673179|isArray()；|673180|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$]]|$1|G|3|H|5|F|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|F|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|F|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<pre><code>JsonNode jsonNode=mapper.readTree(patchBody);
</code></pre>
jsonNode has two method: 
isObject(); 
isArray();

I am going to receive either a JSON Object or Array from server, but I have no idea which it will be. I need to work with the JSON, but to do so, I need to know if it is an Object or an Array.

I am working with Android.

Does any one have a good way of doing this?

Determine whether JSON is a JSONObject or JSONArray

服务器

Android

JSON

我将从服务器接收一个JSON对象或数组，但我不知道是哪一个。我需要使用JSON，但要做到这一点，我需要知道它是一个对象还是一个数组。我正在使用Android。有没有人有好办法做到这一点？

问判断JSON是JSONObject还是JSONArray
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