JSONArray to String[]?

Question

如何从JSONArray中获取字符串数组?

String[] d;
protected void parseJsonString(ArrayList<String[]> deptList,String json){
        try {
            JSONArray array=new JSONArray(json);
            int dl = array.length();
            System.out.println(dl);
            for(int i=0;i<array.length();i++){
                d[i] = array.getString(i);
            }
            deptList.add(d);
            for (String e : d) {
                System.out.println(e);
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

我调试这段代码，我得到一个错误NullPointerException:

d[i] = array.getString(i);

Answer 1

你忘了

String[] d = new String[array.length];

所以String数组d永远不会被初始化。你试着访问它的第一个元素d[i]

Answer 2

您没有初始化字符串数组:

int dl = array.length();
System.out.println(dl); 
String[] d = new String[dl];