如何在JAVA中打印对象数组

Question

I want to print from object like this :

{"data":[["Tiger Nixon","System  
  Architect","Edinburgh","5421","2011\/04\/25","$320,800"],["Garrett     
  Winters","Accountant","Tokyo","8422","2011\/07\/25","$170,750"]]}

i tried in java like this :

ArrayList<String> list = new ArrayList<String>();
list.add("Tiger Nixon");
list.add("System Architect");
list.add("Edinburgh");
list.add("2011\/04\/25");
list.add("$320,800");
JSONArray stateArray = JSONFactoryUtil.createJSONArray();
JSONObject stateObject;

stateObject = JSONFactoryUtil.createJSONObject();
stateObject.put("data", list);  // i got an error in here

stateArray.put(stateObject);
System.out.println(stateArray);

But, i don't know how to implement object like that. There's anyone can help me ?

Answer 1

You can achieve your objective like this:

JSONArray stateArray = JSONFactoryUtil.createJSONArray();
stateArray.put("Tiger Nixon");
stateArray.put("System Architect");
stateArray.put("Edinburgh");
stateArray.put("2011\/04\/25");
stateArray.put("$320,800");

JSONObject stateObject;
stateObject = JSONFactoryUtil.createJSONObject();
stateObject.put("data", stateArray);
System.out.println(stateObject.toString());

Answer 2

ArrayList <String> list = new ArrayList <String>();
list.add("Tiger Nixon");
list.add("System Architect");
JSONArray array = new JSONArray();
for (int i = 0; i < list.size(); i++) {
        array.put(list.get(i));
}
JSONObject object = new JSONObject();
try {
    obj.put("data", array);
} catch (JSONException e) {
e.printStackTrace();
}

Answer 3

Note :- Here JSONObject class whatever i used belongs to org.json.simple Jar Only. I used this class org.json.simple.JSONObject

What you have tried is. You are trying to create a JSONObject of Type ArrayList<String> which will not give you the expected Result, because your json array format is such like that

[["","",""],["","",""],["","",""],["","",""]] // arraylist inside an arraylist.

Your format like that a ArrayList inside an ArrayList but what you try is using only one ArrayList .

Here is your Code.

 ArrayList<String> list = new ArrayList<String>(); //only one arrayList.
    list.add("Tiger Nixon"); // adding values to the list.
    list.add("System Architect");
    list.add("Edinburgh");
    list.add("2011\/04\/25");
    list.add("$320,800");

Your Code will give output like this..

[{"data":"["","",""]"}, {"data":"["","",""]"}, {"data":"["","",""]"}]

Try this code instead of yours (below is just for sample use please try to manipulate this logic as per your need). this will give you the expected Result.

ArrayList<ArrayList<String>> final_arrObject = new ArrayList<ArrayList<String>();
 ArrayList<String> list;
 for(int i=0; i<5; i++){ //demo to add 5 ArrayList<String> to an ArrayList<ArrayList<String>>.
    list = new ArrayList<String>(); //only one arrayList.

     //at each iteration you may change you ArrayList Values.
    list.add("Tiger Nixon");    // adding values to the list.
    list.add("System Architect");
    list.add("Edinburgh");
    list.add("2011\/04\/25");
    list.add("$320,800");
    final_arrObject.add(list);
}

JSONObject obj_finalJSON= new JSONObject();
obj_finalJSON.put("data", final_arrObject);
System.out.println(obj_finalJSON.toString());  //it will print your json as a String.

Answer 4

There is a model,and some properties in it. You can new some model info ,and add it to a List. Then put this list to JSON,and print it json.toString(). If you want specific code, send message to me!