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https://issues.apache.org/jira/browse/SQOOP-1795?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Qian Xu updated SQOOP-1795:
---------------------------
Description:
Sqoop client posts parameters as JSON to server. As it is not query string
based pattern, {{HttpServletRequest}} is not able to return the JSON using
{{getParameterValue(...)}}. The current solution is to call {{getReader()}} to
get raw post data. There is a danger that if the method is NOT called at the
first place. As reading position is no longer at the beginning. Consequentially
you might get unexpected result without notice.
SQOOP-1784 is a unfortunate case.
{code}
// 2 line unlucky code
String username = ctx.getUserName(); // The method will change reading position
of reader internally
JSONObject postData = (JSONObject)
JSONValue.parse(ctx.getRequest().getReader()); // No contents read
// 2 line lucky code
JSONObject postData = (JSONObject)
JSONValue.parse(ctx.getRequest().getReader()); // Good
String username = ctx.getUserName(); // Good
{code}
In practice, it'd suggest to use query string base pattern, i.e.
jsonObject=JSON. The server can call {{ctx.getParameterValue("jsonObject")}} to
get the value without any problem. But we need to change the api.
Now it is perfectly clear:
1. For query string based pattern, caller should always use
{{getParameterValue(...)}}.
2. For raw post data usage, the post data is parsed as the first parameter's
key. So I'd suggest to add {{RequestContext.getFirstParameterName()}}. so that
we can keep fingers away from {{getReader()}}.
was:
The situation of dealing with the post data is very tricky IMHO.
1. {{getRequest().getReader()}} must be called at the first place. As reading
position cannot be reset, you might get unexpected result without notice.
SQOOP-1784 is a case of the situation.
2. Sqoop client sends post data as a JSON object rather than query string
format. Usually it'd suggest to wrap the JSON object as value, and key can be
named as "jsonObject". The server will call
{{ctx.getParameterValue("jsonObject")}} to get the value.
I'd suggest to have a {{getRawPostData()}}, so that callers can put finger away
from {{getReader()}}.
> Sqoop2: Retrieve Http post data in plausible manner
> ---------------------------------------------------
>
> Key: SQOOP-1795
> URL: https://issues.apache.org/jira/browse/SQOOP-1795
> Project: Sqoop
> Issue Type: Sub-task
> Reporter: Qian Xu
> Assignee: Qian Xu
> Fix For: 1.99.5
>
>
> Sqoop client posts parameters as JSON to server. As it is not query string
> based pattern, {{HttpServletRequest}} is not able to return the JSON using
> {{getParameterValue(...)}}. The current solution is to call {{getReader()}}
> to get raw post data. There is a danger that if the method is NOT called at
> the first place. As reading position is no longer at the beginning.
> Consequentially you might get unexpected result without notice.
> SQOOP-1784 is a unfortunate case.
> {code}
> // 2 line unlucky code
> String username = ctx.getUserName(); // The method will change reading
> position of reader internally
> JSONObject postData = (JSONObject)
> JSONValue.parse(ctx.getRequest().getReader()); // No contents read
> // 2 line lucky code
> JSONObject postData = (JSONObject)
> JSONValue.parse(ctx.getRequest().getReader()); // Good
> String username = ctx.getUserName(); // Good
> {code}
> In practice, it'd suggest to use query string base pattern, i.e.
> jsonObject=JSON. The server can call {{ctx.getParameterValue("jsonObject")}}
> to get the value without any problem. But we need to change the api.
> Now it is perfectly clear:
> 1. For query string based pattern, caller should always use
> {{getParameterValue(...)}}.
> 2. For raw post data usage, the post data is parsed as the first parameter's
> key. So I'd suggest to add {{RequestContext.getFirstParameterName()}}. so
> that we can keep fingers away from {{getReader()}}.
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