如何在 JSON 响应中的 2 个对象之间添加换行符？还有如何从 json 文件中删除 [ ] 方括号？

Question

我也尝试使用 line.separator 和 \n。但它不起作用。这是我的代码：

        ResultSetMetaData rsmd = rs.getMetaData();
        JSONArray json = new JSONArray();
        while (rs.next()) {
            int numColumns = rsmd.getColumnCount();
            JSONObject obj = new JSONObject();
            for (int i = 1; i <= numColumns; i++) {
                String column_name = rsmd.getColumnName(i);
                obj.put(column_name, rs.getObject(column_name));
            }

            json.put(obj);
        }
        PrintWriter file = new PrintWriter("JFile.json");
            file.println(json);
            file.close();

    } catch (SQLException | FileNotFoundException e) {
        e.printStackTrace();
    }

编辑 1 这是更新后的 JSONObject 代码，还在对象中添加缩进因子显示 com.fasterxml.jackson.core.io.JsonEOFException: Unexpected end-of-input: expected close marker for Object:

ResultSetMetaData rsmd = rs.getMetaData();
        JSONObject obj = new JSONObject();
        while (rs.next()) {
            int numColumns = rsmd.getColumnCount();
            for (int i = 1; i <= numColumns; i++) {
                String column_name = rsmd.getColumnName(i);
                obj.put(column_name, rs.getObject(column_name));
            }
        }
        PrintWriter file = new PrintWriter("downloads/JSONFile.json");
        file.println(obj.toString());
        file.close();
    } catch (SQLException | FileNotFoundException e) {
        e.printStackTrace();
    }

Answer 1

ResultSetMetaData rsmd = rs.getMetaData();
JSONArray jsonArr = new JSONArray();
while (rs.next()) {
    int numColumns = rsmd.getColumnCount();
    JSONObject obj = new JSONObject();
    for (int i = 1; i <= numColumns; i++) {
           String column_name = rsmd.getColumnName(i);
           obj.put(column_name, rs.getObject(column_name));
        }
        jsonArr.put(obj);
   }        
//add this JSONArray to another JSONObject 
JSONObject rootJSONObject = new JSONObject();
rootJSONObject.put("data",jsonArr);

PrintWriter printWriter = new PrintWriter("sample.json");
printWriter.write(rootJSONObject.toString(4).replace("{", "\n{\n").replace("}", "\n}\n"));
printWriter.close();

如何在 JSON 响应中的 2 个对象之间添加换行符？还有如何从 json 文件中删除 [ ] 方括号？

How to add newline between the 2 objects in JSON response ? And also how to remove the [ ] square brackets from the json file?

java

json

newline

file

printwriter