Question

因此，在JSONArray中添加新的JSONObject时会遇到很多麻烦。

我的代码是西班牙语，所以我将尽我所能在我的注释中尽量将变量和方法转换为英语。

这是我的.JSON（默认用户的所有属性都为“ admin”）：

{"Usuarios":[{"nombre":"Admin","apellido":"Admin","direccion":"Admin","telefono":"Admin","correo":"Admin@admin.com","username":"admin","password":"admin"}]}

首先，我创建了函数，这些函数可以毫无问题地验证用户“ admin”的属性。因此，在读取JSON文件时，仅在其上书写就不会有问题：

这是使用此功能的问题：

public void agregarUsuario(String nombre, String apellido, String direccion, String telefono, String correo, String username, String password) //this function add a new user object to my array in the json
{
    try {
        JSONObject usuarios = getJSONObjectFromFile("/usuarios.json"); //Json object "usuarios"/"users" is my main json obj file
        JSONArray listaUsuario = usuarios.getJSONArray("Usuarios");     //I've start my array "Usuarios" (who is in my .json)
        JSONObject newObject = new JSONObject();                        //I created a new JSONObjectVariable, with the attributes i want in it
        newObject.put("nombre", nombre);
        newObject.put("apellido", apellido);
        newObject.put("direccion", direccion);
        newObject.put("telefono", telefono);
        newObject.put("correo", correo);
        newObject.put("username",username);
        newObject.put("password", password);
                                                                        //at this point my new object has all the attributes i want to put in my array
        listaUsuario.put(newObject);                                    //so here i tried to put in my array my new Json object
        usuarios.put("Usuarios",listaUsuario);                          //this line, is one of my attempts to figure out how to put the function working
                                                                        //it wasn't in the first time, but how listaUsuario.put(newObject) dint make any change in my .json...
                                                                        //with or without it doesn't do anything 
    }catch(JSONException e) {
        e.printStackTrace();
    }
 }

这个“写”函数不会在我的json文件“ /usuarios.json”中进行任何更改，但是，我实际上可以毫无问题地读取json。例如，我项目的此其他功能读取我的json文件，以查看登录名JFrame的密码和用户名是否匹配：

public boolean verificarInicioDeUsuario(String incomeUsername,String incomePassword) {
   JSONArray listaUsuario = usuarios.getJSONArray("Usuarios"); //gets in my "Usuarios"/"User" array
   for(int j=0;j<listaUsuario.length();j++) {                   //Start reading my array
        JSONObject user = listaUsuario.getJSONObject(j);        //i make a new JSONObject for use it to compare my strings
        if((user.getString("username").equals(incomeUsername))&&(user.getString("password").equals(incomePassword))) { //I compare my object username attributes with my incomeStrings
        return true;     //if the username and password matches in the same object, returns true
        }
     }
     return false; //if not, returns false
 }

有什么建议/帮助吗？ <3

Answer 1

您仅将加载的JSON对象更改为内存。您尚未将其写入文件。请使用下面的代码示例，并根据您的程序进行更改。

所以这里的主要问题是：在JSONObject上调用toString，然后序列化该字符串。 JSONObject本身不可序列化。所以您必须在下面使用：

String jsonString = jsonObject.toString();

示例代码：

 public void agregarUsuario(String nombre, String apellido, String direccion, String telefono, String correo, String username, String password) //this function add a new user object to my array in the json
{
    try {
        JSONObject usuarios = getJSONObjectFromFile("/usuarios.json"); //Json object "usuarios"/"users" is my main json obj file
        JSONArray listaUsuario = usuarios.getJSONArray("Usuarios");     //I've start my array "Usuarios" (who is in my .json)
        JSONObject newObject = new JSONObject();                        //I created a new JSONObjectVariable, with the attributes i want in it
        newObject.put("nombre", nombre);
        newObject.put("apellido", apellido);
        newObject.put("direccion", direccion);
        newObject.put("telefono", telefono);
        newObject.put("correo", correo);
        newObject.put("username",username);
        newObject.put("password", password);
                                                                        //at this point my new object has all the attributes i want to put in my array
        listaUsuario.put(newObject);                                    //so here i tried to put in my array my new Json object
        usuarios.put("Usuarios",listaUsuario);                          //this line, is one of my attempts to figure out how to put the function working
                                                                        //it wasn't in the first time, but how listaUsuario.put(newObject) dint make any change in my .json...
                                                                        //with or without it doesn't do anything 

        ObjectOutputStream outputStream = null;

           outputStream = new ObjectOutputStream(new FileOutputStream("/usuarios.json"));
           System.out.println("Start Writing in to file ");
            outputStream.writeObject(usuarios.toString());
            outputStream.flush();
            outputStream.close();

    }catch(JSONException e) {
        e.printStackTrace();
    }
    catch (Exception e){
        System.err.println("Error writting json: " + e);
    }
 }

在JSONArray中创建JSONObject（JSON-Simple / JAVA）

1 个答案: