Convert JSON array[array[String]] to Java array

Question

I have a JavaScript JSON array[array[String]] called jsonArray in my JSP1.jsp.

I am converting jsonArray to a String jsonArrayStr using JSON.stringify(jsonArray) in JSP1.jsp.

I am passing jsonArrayStr as a parameter while calling another JSP JSP2.jsp this way-

"JSP2.do?jsonArrayStr="+jsonArrayStr

In JSP2.jsp, I am doing this-

String jsonArrayStr = request.getParameter("jsonArrayStr");

Now how do I convert jsonArrayStr to Java array (JSP2.jsp doesn't contain any JavaScript code)

Summary-

I have a JavaScript JSON Array in a JSP1.jsp, which I want to access as a normal Java array/arraylist in JSP2.jsp. How do I achieve this?

• sdouglass: Are you starting out with a one-dimensional array, or a two-dimensional array? Does your array contain just Strings, or does it contain arrays that contain strings? JSON.stringify() on e one-dimensional array would look like: ["a", "b", "c", "x", "y", "z"] JSON.stringify() on a two-dimensional array would look like: [["a", "b", "c"],["x"],["y","z"]]
• AlwaysALearner: it looks like [["a", "b", "c"],["x"],["y","z"]]
• Parvathy: @user1649068 you want to create a array of java objects from jsonarray?

Answer 1

OK, so you have a two-dimensional array of strings represented as a JSON like this stored in a Java String:

[["a", "b", "c"],["x"],["y","z"]]

You need to somehow parse or "deserialize" that value into a Java String[][]. You can use a library like from http://www.json.org/java/index.html or http://jackson.codehaus.org/ or you can try to do it manually. Manually could be a little tricky but not impossible. The json.org library is very simple and might be good enough. The code would be something like this (I haven't tried/tested this):

JSONArray jsonArray = new JSONArray(jsonArrayStr); // JSONArray is from the json.org library
String[][] arrayOfArrays = new String[jsonArray.length()][];
for (int i = 0; i < jsonArray.length(); i++) {
 JSONArray innerJsonArray = (JSONArray) jsonArray.get(i);
 String[] stringArray = new String[innerJsonArray.length()];
 for (int j = 0; j < innerJsonArray.length(); j++) {
 stringArray[j] = innerJsonArray.get(j);
 }
 arrayOfArrays[i] = stringArray;
}

Answer 2

somethingk like this

ArrayList<String> strings= new ArrayList<String>(); 
JSONArray jsonArray = (JSONArray)jsonObject; 
if (jsonArray != null) { 
 int len = jsonArray.length();
 for (int i=0;i<len;i++){ 
 list.add(jsonArray.get(i).toString());
 } 
} 
String[] Stringarray = strings.toArray(new String[strings.size()]);

• AlwaysALearner: According to my question, what is JSONObject here? jsonArray or jsonArrayStr?
• AlwaysALearner: So, u mean to say there is no need for me to stringify() the json object? I will be able to directly access the JSONobject across JSP pages without passing them?
• TheWhiteRabbit: yes, directly pass the jsonArray as request parameter to jsp2 and in jsp2 do as mentioned above :)
• AlwaysALearner: are you talking about net.sf.json.JSONArray
• AlwaysALearner: This is how I am passing the array value to another JSP as u said- "JSP2.do?jsonArray="+jsonArray;