ExtJs 3.4：从 Ajax 响应中检索数据

Question

我正在使用 ExtJs 3.4 并且我有一个组合框。当用户从这个组合中选择一个值时，将调用 Ajax 请求根据选择的值从我的 postgresql 数据库中检索数据。

listeners : {
            select : function() {
                var selVehicleCode = Ext.getCmp('vehicleCombo').getValue();
                var selFromDate = Ext.getCmp('fromDateCombo').getValue();

                Ext.Ajax.request({
                      method: 'GET',
                      loadMask: true,
                      scope: this,
                      url: "http://" + host + ":" + port + "/" + projectName + "/"
                            + "SetDefaultValues",
                      success: function (response, request) {
                        Ext.MessageBox.alert('success', response.responseText);

                      },
                      failure: function (response, request) {
                        Ext.MessageBox.alert('failure', response.responseText);
                      },
                      params : {
                        selectedVCode : selVehicleCode,
                        selectedFromDate : selFromDate.format('Y-m-d')
                      }
                 });

            }

        }

这是我的 SetDefaultValues.java servlet。

//imports
public class SetDefaultValues extends HttpServlet {
private static final long serialVersionUID = 1L;

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

@Override
public void init() throws ServletException {
    // TODO Auto-generated method stub
    super.init();
}

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
 *      response)
 */
protected void doGet(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    processRequest(request, response);
}

/**
 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse
 *      response)
 */
protected void doPost(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {
    // TODO Auto-generated method stub
    processRequest(request, response);
}

protected void processRequest(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();

    ServletContext context = getServletContext();

    String dbName = context.getInitParameter("ConnectionDB");
    String connectionHost = context.getInitParameter("ConnectionHost");
    String connectionUser = context.getInitParameter("ConnectionUser");
    String connectionPassword = context
            .getInitParameter("ConnectionPassword");
    String port = "5433";

    Statement statement = null;
    ResultSet defaultSet = null;
    Connection pgConnection = null;
    // String lineString = "";

    try {
        pgConnection = ConnectionManager.getPostgresConnection(
                connectionHost, connectionUser, connectionPassword, dbName,
                port);
        // out.println(connectionHost+","+ connectionUser+","+
        // connectionPassword+","+ dbName);
        statement = pgConnection.createStatement();
        // out.print(pgConnection);

        String vCode = request.getParameter("selectedVCode");
        String fromDate = request.getParameter("selectedFromDate");
        // out.print(fromDate);
        // out.print(vCode);

        String sql = "";

        sql += "SELECT v.vehiclecode, v.employeecode, e.name, e.employeecategory";
        sql += " FROM hoobtvehcileemplyees v, hoobtemplyees e";
        sql += " WHERE v.employeecode = e.employeecode AND";
        sql += " v.vehiclecode = " + vCode + " AND v.datefrom < '" + fromDate + "' AND v.dateto > '" + fromDate + "'";

        defaultSet = statement.executeQuery(sql);

        String jsonData = "{'defaultVal':[";

        while (defaultSet.next()) {
            jsonData += "{ 'category' : '";
            jsonData += defaultSet.getString(4).trim();
            jsonData += "', ";
            jsonData += "'name' : '";
            jsonData += defaultSet.getString(3).trim();

            if (defaultSet.isLast()) {
                jsonData += "' }  ";
            } else {
                jsonData += "' } , ";
            }
        }

        jsonData += "]}";
        out.print(jsonData);

    } catch (Exception e) {
        // TODO Auto-generated catch block
        out.println(e.toString());
        e.printStackTrace();

    }

}

}

这是我的 Ajax 响应。

{'defaultVal':[{ 'category' : '1', 'name' : 'Kamal Subhasingha' } , { 'category' : '2', 'name' : 'Namal Witharana' } , { 'category' : '3', 'name' : 'Yohan' } , { 'category' : '4', 'name' : 'Ahan Liyanage' } , { 'category' : '5', 'name' : 'Sampath Jayaweera' } , { 'category' : '6', 'name' : 'Saman' } ]}

现在我需要检索关于类别 3 和类别 5 的名称字段。我应该将这些值设置为我的组合框值（我有两个组合框）。我试过了。

var jsonData = Ext.util.JSON.decode(response.responseText);
console.log(jsonData);
alert(jsonData.name);

它打印 jsonData。但它会发出未定义的警报。

我的代码有什么问题？有人有想法吗？

如果有人请您解释我的代码出了什么问题以及我应该如何做这样的事情，我将非常感激。

谢谢

Answer 1

您忘记了包含其他对象的 defaultVal 参数。

console.log(jsonData.defaultVal);

你可以访问'name'属性