java - 我遇到数字格式异常

Question

当我尝试在servelt中接受id时，我收到数字格式异常JSJP 页面:

    var associates = document.getElementsByName("resourceId");
    //var associates=document.getElementById(elementId).value;
        var id = "";
        for ( var i = 0; i < associates.length; i++) {
            if (associates[i].checked) {
                //alert(associates[i]);
                id = associates[i].value;
                alert(id);
                break;
            }
        }

我试图接受来自jsp文件的id值并将其发送到我的dao类，但是当我尝试接受id值时出现数字格式异常

Servlet:

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    System.out.println("in dopost");        
    //number format exception in this line
    int associateID = Integer.parseInt(request.getParameter("id"));
    if (dao.deleteAssociate(associateID)) {
        System.out.println("deleted");
    }
    // System.out.println(associateID);
}

Answer 1

您正在尝试获取 HTML 网页元素的“id”，它不是 JavaScript 变量。

另一方面，我建议在执行 parseInt 之前使用 instanceof 运算符。

例如:

int associateID = -1;
Object obj = request.getParameter("id");
if(null != obj && obj instanceof Number) {
    associateID = Integer.parseInt(request.getParameter("id"));
    if (dao.deleteAssociate(associateID)) {
        System.out.println("deleted");
    }
}