restfull路由如下:
router.get('/:id', controller.show); mongoes代码如下:
exports.show = function(req, res) {
Notice.findById(req.params.id, function (err, notice) {
if(err) {
res.json({no:0,msg:'获取失败:'+err});
}else{
var result = {no:1};
result.obj=notice;
res.json(result);
}
});
};
客户端访问:
http://192.168.0.165:9000/api/notices/11
打印结果如下;
{
"no": 0,
"msg": "获取失败:CastError: Cast to ObjectId failed for value \"11\" at path \"_id\""
}
具体原因参考:
http://*.com/questions/14940660/whats-mongoose-error-cast-to-objectid-failed-for-value-xxx-at-path-id
Mongoose's findById
method casts the id
parameter to the type of the model's _id
field so that it can properly query for the matching doc. This is an ObjectId but "11"
is not a valid ObjectId so the cast fails.
如果客户端传递的是mongo ObjectId就不会报以上错误.例如以下访问方式:
http://192.168.0.165:9000/api/notices/41224d776a326fb40f000001 就不会报错.
{
"no": 1,
"obj": null
}
在正常情况下,客户端传递的id参数是从后台获取的ObjectId,但是为了严谨性现在做以下处理:
exports.show = function(req, res) {
var id = req.params.id; if (id.match(/^[0-9a-fA-F]{24}$/)) {
Notice.findById(id, function (err, notice) {
if(err) {
res.json({no:0,msg:'获取失败:'+err});
}else{
var result = {no:1};
result.obj=notice;
res.json(result);
}
});
}else{
res.json({no:0,msg:id+'不存在'});
} };