How to convert json to associative array in JSP - json

Question

I'm trying to make a dynamic jsp page based on the json.
For example, if my json is look like this:
{
'page1':'true',
'page2':'true',
'page3':'false'
}
In php, I could get my associative array easily by one line:
$data = json_decode($json_str);
Then I could access whichever that I wanted at the place I needed, (i.e)
If($data['page1'] == 'true')
echo #page link#;
But in jsp, it doesn't goes so easily because it don't have much documents like php. I find the gson but still not sure. how to use it to achieve it.
Please give me some example that I could turn json to associative array, then get and access it in jsp.

Answer 1

A Java Map is an associative array. You can ask Gson to deserialize your json input with this:
Map<String,String> map = new Gson().fromJson(inputJson, new TypeToken<Map<String,String>>() {}.getType());
Example code:
package net.sargue.gson;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.lang.reflect.Type;
import java.util.Map;
public class SO36859440 {
public static void main(String[] args) {
String inputJson = "{\n" +
" 'page1':'true',\n" +
" 'page2':'true',\n" +
" 'page3':'false'\n" +
"}";
Type type = new TypeToken<Map<String, String>>() {}.getType();
Map<String,String> map = new Gson().fromJson(inputJson, type);
System.out.println(map.get("page2"));
System.out.println(map.get("page3"));
}
}
The output is:
true
false
Then, your question is about converting it in JSP. Well, best practices for JSP advice you to move this kind of processing to a Servlet that acts as a controller and passes attributes to the JSP in order to build the view. You can put code directly on the JSP using <% ... %> but I highly discourage you to do so. But that's an entirely different question.