Android: JSONObject cannot be converted to JSONArray

问题:

I want to get data from php file to Android using JSON. This is my code:

.... HttpEntity e = r.getEntity(); String data = EntityUtils.toString(e); JSONArray timeline = new JSONArray(data); JSONObject last = timeline.getJSONObject(0); return last; 

When I debug the program there is JSONException on this line:

JSONObject last = timeline.getJSONObject(0); 

Data is {"a":1,"b":2,"c":3,"d":4,"e":5} and the Exception is:

org.json.JSONException: Value {"d":4,"e":5,"b":2,"c":3,"a":1} of type org.json.JSONObject cannot be converted to JSONArray 

回答1:

The exception message is quite explicit and a look at the JSON syntax diagrams should be illustrative. The JSON string that your code received is:

{"a":1,"b":2,"c":3,"d":4,"e":5} 

This string represents an object, not an array. An example of an array would be this:

[1, 2, 3, 4, 5] 

or even this:

[{"a":1,"b":2,"c":3,"d":4,"e":5}] 

Note that starting and closing brackets.

I think that you will find that the exception location is slightly misleading. I don't know if it is a result of some sort of lazy initialization or something else, but I believe that the cause is actually this line:

JSONArray timeline = new JSONArray(data); 

Since the data string represents a JSON object and not an array, this operation is clearly impossible.

回答2:

In Json arrays are described using []. There you define an object with five attributes.

回答3:

JSONArray timeline = new JSONArray(data); // change JSONArray to JSONObject  JSONObject timeline = new JSONObject(data);// Like This 

Your JSON data is not an array.

回答4:

Your json response is in Object form, not in Array form.So you have to simply parse your json object. Suppose "data" is the JSONObject tag in response. Following is the way of Parsing:

           HttpEntity e = r.getEntity();            String result = EntityUtils.toString(e);            JSONObject response=new JSOBObject(result);            JSONOBject Data=response.getJSONObject("data");            int a=Data.getInt("a");            int b=Data.getInt("b");            int c=Data.getInt("c");            int d=Data.getInt("d");            int e=Data.getInt("e"); 

Thanks.

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