java JSON空值和空值在JSON对象中为true

Question

如果我在JSON对象中添加空值或空值，则JSON值为true

$scope.getUserData = function (){   
    $.ajax({
          url: "/test.com/abc.jsp",
          type: "POST",
          dataType: "json",
          data: {
            action : "getUserData",
            id : Id,
            logView:"true",
        },
          async:false,
          success: function(data){
            // data is json array and userData is json object           
            $scope.userData = JSON.parse(data.userData);
            $scope.userData.uname // comes as true but from server it is set as blank
          });
    });
}

在服务器端java代码中，我从数据中获得的值为blank/null，但在JSON对象中，值为true，表示blank/null。它在我的本地环境中工作，但在服务器环境中，对于blank/null则是如此