blocks|key|1430898|text|您是否尝试过使用JSONArray.getJSONObject(int)和JSONArray.length()来创建您的for循环：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1430899|for+(int+i+=+0;+i+<+recs.length();+%2B%2Bi)+{
++++JSONObject+rec+=+recs.getJSONObject(i);
++++int+id+=+rec.getInt("id");
++++String+loc+=+rec.getString("loc");
++++//+...
}|code-block|syntax|javascript|1430900|entityMap|0|LINK|mutability|MUTABLE|url|http://json.org/javadoc/org/json/JSONArray.html#getJSONObject(int))|1|http://json.org/javadoc/org/json/JSONArray.html#length()^0|8|S|0|11|I|1|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]|$A|W|B|X|1|Y]]|C|$]]|$1|D|3|E|5|F|7|Z|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|10|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]|Q|$5|L|M|N|C|$O|R]]]]

Have you tried using <a href="http://json.org/javadoc/org/json/JSONArray.html#getJSONObject(int)" rel="noreferrer">JSONArray.getJSONObject(int)</a>, and <a href="http://json.org/javadoc/org/json/JSONArray.html#length()" rel="noreferrer">JSONArray.length()</a> to create your for-loop:

<pre><code>for (int i = 0; i &lt; recs.length(); ++i) {
 JSONObject rec = recs.getJSONObject(i);
 int id = rec.getInt("id");
 String loc = rec.getString("loc");
 // ...
}
</code></pre>

blocks|key|1216108|text|通过查看您的代码，我感觉您正在使用JSONLIB。如果是这种情况，请查看以下代码片段以将json数组转换为java数组。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1216109|+JSONArray+jsonArray+=+(JSONArray)+JSONSerializer.toJSON(+input+);++
+JsonConfig+jsonConfig+=+new+JsonConfig();++
+jsonConfig.setArrayMode(+JsonConfig.MODE_OBJECT_ARRAY+);++
+jsonConfig.setRootClass(+Integer.TYPE+);++
+int[]+output+=+(int[])+JSONSerializer.toJava(+jsonArray,+jsonConfig+);++|code-block|syntax|javascript|1216110|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|$]]

By looking at your code, I sense you are using JSONLIB. If that was the case, look at the following snippet to convert json array to java array..

<pre><code> JSONArray jsonArray = (JSONArray) JSONSerializer.toJSON( input ); 
 JsonConfig jsonConfig = new JsonConfig(); 
 jsonConfig.setArrayMode( JsonConfig.MODE_OBJECT_ARRAY ); 
 jsonConfig.setRootClass( Integer.TYPE ); 
 int[] output = (int[]) JSONSerializer.toJava( jsonArray, jsonConfig ); 
</code></pre>

blocks|key|1430974|text|org.json.JSONArray是不可迭代的。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1430975|下面是我如何处理net.sf.json.JSONArray中的元素|1430976|++++JSONArray+lineItems+=+jsonObject.getJSONArray("lineItems");
++++for+(Object+o+:+lineItems)+{
++++++++JSONObject+jsonLineItem+=+(JSONObject)+o;
++++++++String+key+=+jsonLineItem.getString("key");
++++++++String+value+=+jsonLineItem.getString("value");
++++++++...
++++}|code-block|syntax|javascript|1430977|效果很好。:)|1430978|entityMap|0|LINK|mutability|MUTABLE|url|http://www.json.org/javadoc/org/json/JSONArray.html|1|http://json-lib.sourceforge.net/apidocs/net/sf/json/JSONArray.html^0|0|I|0|0|8|L|1|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|6|7|10|8|@]|9|@$A|11|B|12|1|13]]|C|$]]|$1|F|3|G|5|H|7|14|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|15|8|@]|9|@]|C|$]]|$1|M|3|-4|5|6|7|16|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]|U|$5|P|Q|R|C|$S|V]]]]

An <a href="http://www.json.org/javadoc/org/json/JSONArray.html" rel="noreferrer">org.json.JSONArray</a> is not iterable. 
Here's how I process elements in a <a href="http://json-lib.sourceforge.net/apidocs/net/sf/json/JSONArray.html" rel="noreferrer">net.sf.json.JSONArray</a>:

<pre><code> JSONArray lineItems = jsonObject.getJSONArray("lineItems");
 for (Object o : lineItems) {
 JSONObject jsonLineItem = (JSONObject) o;
 String key = jsonLineItem.getString("key");
 String value = jsonLineItem.getString("value");
 ...
 }
</code></pre>

Works great... :)

blocks|key|1216199|text|如果它对其他人有帮助，我可以通过执行以下操作转换为数组，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1216200|JSONObject+jsonObject+=+(JSONObject)new+JSONParser().parse(jsonString);
((JSONArray)+jsonObject).toArray()|code-block|syntax|javascript|1216201|...or你应该能够得到长度|1216202|((JSONArray)+myJsonArray).toArray().length|1216203|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|$]]

In case it helps someone else, 
I was able to convert to an array by doing something like this, 

<pre><code>JSONObject jsonObject = (JSONObject)new JSONParser().parse(jsonString);
((JSONArray) jsonObject).toArray()
</code></pre>

...or you should be able to get the length 

<pre><code>((JSONArray) myJsonArray).toArray().length
</code></pre>

blocks|key|1431112|text|java8在近20年后上市，下面是用java8+Stream+API迭代org.json.JSONArray的方法。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1431113|import+org.json.JSONArray;
import+org.json.JSONObject;

@Test
public+void+access_org_JsonArray()+{
++++//Given:+array
++++JSONArray+jsonArray+=+new+JSONArray(Arrays.asList(new+JSONObject(
++++++++++++++++++++new+HashMap()+{{
++++++++++++++++++++++++put("a",+100);
++++++++++++++++++++++++put("b",+200);
++++++++++++++++++++}}
++++++++++++),
++++++++++++new+JSONObject(
++++++++++++++++++++new+HashMap()+{{
++++++++++++++++++++++++put("a",+300);
++++++++++++++++++++++++put("b",+400);
++++++++++++++++++++}}
++++++++++++)));

++++//Then:+convert+to+List<JSONObject>
++++List<JSONObject>+jsonItems+=+IntStream.range(0,+jsonArray.length())
++++++++++++.mapToObj(index+->+(JSONObject)+jsonArray.get(index))
++++++++++++.collect(Collectors.toList());

++++//+you+can+access+the+array+elements+now
++++jsonItems.forEach(arrayElement+->+System.out.println(arrayElement.get("a")));
++++//+prints+100,+300
}|code-block|syntax|javascript|1431114|如果迭代只有一次，(不需要.collect)|1431115|++++IntStream.range(0,+jsonArray.length())
++++++++++++.mapToObj(index+->+(JSONObject)+jsonArray.get(index))
++++++++++++.forEach(item+->+{
+++++++++++++++System.out.println(item);
++++++++++++});|1431116|entityMap^0|10|I|0|0|D|8|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

Java 8 is in the market after almost 2 decades, following is the way to iterate <code>org.json.JSONArray</code> with java8 Stream API.

<pre><code>import org.json.JSONArray;
import org.json.JSONObject;

@Test
public void access_org_JsonArray() {
 //Given: array
 JSONArray jsonArray = new JSONArray(Arrays.asList(new JSONObject(
 new HashMap() {{
 put("a", 100);
 put("b", 200);
 }}
 ),
 new JSONObject(
 new HashMap() {{
 put("a", 300);
 put("b", 400);
 }}
 )));

 //Then: convert to List&lt;JSONObject&gt;
 List&lt;JSONObject&gt; jsonItems = IntStream.range(0, jsonArray.length())
 .mapToObj(index -&gt; (JSONObject) jsonArray.get(index))
 .collect(Collectors.toList());

 // you can access the array elements now
 jsonItems.forEach(arrayElement -&gt; System.out.println(arrayElement.get("a")));
 // prints 100, 300
}
</code></pre>

If the iteration is only one time, (no need to <code>.collect</code>)

<pre><code> IntStream.range(0, jsonArray.length())
 .mapToObj(index -&gt; (JSONObject) jsonArray.get(index))
 .forEach(item -&gt; {
 System.out.println(item);
 });
</code></pre>

I'm just getting started with using json with java. I'm not sure how to access string values within a JSONArray. For instance, my json looks like this:

<pre><code>{
 "locations": {
 "record": [
 {
 "id": 8817,
 "loc": "NEW YORK CITY"
 },
 {
 "id": 2873,
 "loc": "UNITED STATES"
 },
 {
 "id": 1501
 "loc": "NEW YORK STATE"
 }
 ]
 }
}
</code></pre>

my code:

<pre><code>JSONObject req = new JSONObject(join(loadStrings(data.json),""));
JSONObject locs = req.getJSONObject("locations");
JSONArray recs = locs.getJSONArray("record");
</code></pre>

I have access to the "record" JSONArray at this point, but am unsure as to how I'd get the "id" and "loc" values within a for loop. Sorry if this description isn't too clear, I'm a bit new to programming.

Accessing members of items in a JSONArray with Java

我刚刚开始在java中使用json。我不确定如何访问JSONArray中的字符串值。例如，我的json如下所示：{  "locations": {    "record": [      {        "id": 8817,        "loc": "NEW YORK CITY"      },      { ...

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