我如何从java servlet到jQuery获取json数据

Question

这是我的servlet：json数组具有对象“ esquina”。 esquina具有两个属性double coordX和double coordY

package servlets;

@WebServlet("/Mapa")
public class ServletMapa  extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public ServletMapa() {
        super();
        // TODO Auto-generated constructor stub
    }


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        Sistema instanciaSys = Sistema.darInstancia();
        instanciaSys.inicializarSistema(6);
        Esquina[] esquinas = instanciaSys.getEsquinas();    
        JSONArray json =new JSONArray();

        JSONObject jO = null;
        for (Esquina esquina : esquinas) {
            jO = new JSONObject(esquina);               
            json.put(jO);   

            System.out.println(json);           
        }


        request.setAttribute("esquinas", esquinas);     
        request.setAttribute("json", json);     


        request.getRequestDispatcher("/gui/Mapa.jsp").forward(request, response);       
    }


    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        doGet(request, response);
    }

}

我需要将数据从jsonArray获取到jquery，我尝试了getJSON（）函数，但没有工作。

这是代码

function cargarMarcadores() {

    var x=$("#iniSistema");
    x.click(function(){ 
                $.getJSON('localhost:8080/Carpuleame/Mapa',function(data){

                    alert("data");
                });
            });

}

有另一种方法吗？

Answer 1

您可能想要这样的东西：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    Sistema instanciaSys = Sistema.darInstancia();
    instanciaSys.inicializarSistema(6);
    Esquina[] esquinas = instanciaSys.getEsquinas();    
    JSONArray json =new JSONArray();

    for (Esquina esquina : esquinas) {
        JSONObject jO = new JSONObject(); 
        jO.put("coordX", esquina.getCoordX());              
        jO.put("coordY", esquina.getCoordY());              
        json.put(jO);   

    }

    // tell the client that JSON is coming
    response.setContentType("application/json");
    resposne.setCharacterEncoding("UTF-8");
    json.write(response.getWriter());
}

有许多框架可以消除此代码的许多“蛮力”性，但这与您的开始位置非常接近。