如何使用Angularjs从JSON获取数据?

var app = angular.module("app", []);

app.controller('emp', ['$scope', 'empService', function($scope, empService){
    $scope.doSearch = function(){
        empService.findEmployeeById($scope.searchempno, function(r){
            $scope.empno = r.empno;
            $scope.ename = r.ename;
            $scope.salary = r.salary;
            $scope.dptno = r.dptno;
        });
    };
}]);

app.service('empService', ['$http', '$log', function($http, $log){
    this.findEmployeeById = function(empno, cb){
        $http({
            url: 'employees.json' + empno,
            method: 'GET'
        }).then(function(resp){
            cb(resp.data);
        });
    };
}]);var app = angular.module("app", [])