Scala with Spray Routing - accessing GET parameters? - java

I'm currently working on an application built in Scala with Spray routing.
So for dealing with a JSON document sent over POST, it's pretty easy to access the variables within the body, as follows;
respondWithMediaType(`application/json`) {
entity(as[String]) { body =>
val msg = (parse(body) \ "msg").extract[String]
val url = (parse(body) \ "url").extractOpt[String]
However, I'm now trying to write an additional query with GET, and am having some issues accessing the parameters sent through with the query.
So, I'm opening with;
get {
respondWithMediaType(`application/json`) {
parameterSeq { params =>
var paramsList = params.toList
So, this works well enough in that I can access the GET params in a sequential order (just by accessing the index) - the problem is, unfortunately I don't think we can expect GET params to always be sent in the correct order.
The list itself prints out in the following format;
List((msg,this is a link to google), (url,http://google.com), (userid,13))
Is there any simple way to access these params? For example, something along the lines of;
var message = paramsList['msg']
println(message) //returns "this is a link to google"
Or am I going about this completely wrong?
Apologies if this is a stupid question - I've only switched over to Scala very recently, and am still getting both acquainted with that, and re-acquainted with Java.

What I usually do is use the parameters directive to parse the data out to a case class which contains all the relevant data:
case class MyParams(msg: String, url: String, userId: Int)
parameters(
"msg".as[String],
"url".as[String],
"userId".as[Int]
).as[MyParams] {
myParams =>
// Here you have the case class containing all the data, already parsed.
}

To build your routes you could use the parameters directives. I'm not sure if this is what you're looking for, anyway you could use them as:
get {
parameters('msg) { (msg) =>
complete(s"The message is '$msg'")
}
}
Spray directives can be easily composed so you can use combine them in any way you want.
I hope that helps you.

Related

how to create the data model for this { "words":[3,4,5] } json in kotlin

I was trying to write a data model to send a JSON to the API and delete some fields
the JSON should contain the id of some words and it should look exactly like this :
{
"words":[3,4,5]
}
as I know and also as the https://jsonformatter.org/ said the data class should be something like the following piece of code:
data class words(var id: List<Int>)
but the problem is when I pass the data to it and toast it to see if it's a valid JSON request for the server the output will be this :
words(id=[1,2,4,5])
and it's not what it should be.
as I said I need this :
{
"words":[3,4,5]
}
I think the following should work.
data class AnyNameYouWant(val words: List<Int>)
I think the name of the data class really doesn't matter as it would finally represent the { } object syntax of json.
Looking in the comments, I think it's better to use some logging library like Timber. If you are using Retrofit then use can also use HttpLoggingInterceptor and set the level to Body that will print the body of the response in the logcat.

KSQL: UDF does not accept parameters (STRING, STRING)

I'm running in to a problem with KSQL while trying to set up an ETL pipeline using a UDF. At some point in the ETL process I need to isolate specific info from a description field (VARCHAR) in my data. A made-up example for context:
description = "species=dog.sex=male.color=blonde.age=10." (the real data is formatted in the same way)
I've written a simple UDF to isolate any information on demand. It looks like this:
package com.my.package;
/** IMPORTS **/
import io.confluent.ksql.function.udf.Udf;
import io.confluent.ksql.function.udf.UdfDescription;
/** ClASS DEFINITION **/
#UdfDescription(name = "extract_from_description",
author = "Me",
version = "0.0.1",
description = "Given a description and a request for information, isolates and returns the requested information. Pass requested tag as 'tag='".)
public class Extract_From_Description {
#Udf(description = "Given a description and a request for information, isolates and returns the requested information. Pass requested tag as 'tag='.)
public String extract_from_description(final String description, final String request) {
return description.split(request)[1].split("\\.")[0];
}
}
I can upload and register the function just fine, it's listed and described properly when I run:
ksql> list functions;
ksql> describe function EXTRACT_FROM_DESCRIPTION;
I call the function like this to create a new stream:
CREATE STREAM result AS
SELECT recordId,
OtherVariables,
EXTRACT_FROM_DESCRIPTION(description, 'species=') AS species
FROM parent_stream
EMIT CHANGES;
There I get an error I can't make sense of:
Function 'extract_from_description' does not accept parameters (STRING, STRING).
Valid alternatives are:
Apparently KSQL can't properly interpret what the input for the function is supposed to be (looks like it expects no input?) and I can't figure out why. I've read through documentation to see if I define my function in a weird way but can't find any differences between the examples and my function. I did notice there are supposed to be several ways to define the input a function takes and tried them all, but the result is always the same.
I use Maven to create the jar file for this function (JDK1.8.0_201). Can anyone help me figure out what's going on?
TL;DR: My KSQL UDF doesn't accept input of type (String, String) even though the function specifies the input should be of type (String, String)
Found the problem, answering here for anyone that might run in to the same problem.
You need to specify the parameters using #UdfParameter, like this:
import io.confluent.ksql.function.udf.UdfParameter; // add this to the list of imports
// add #UdfParameter(name) to each input variable
public String extract_from_description(#UdfParameter(value = "description") final String description, #UdfParameter(value = "request") final String request){
function body
}

Play Framework Multi-Tenant Filter

I'm attempting to build a multi-tenant application using Play Framework 2.2 and have run into a problem. I want to set a session key in the global onRouteRequest (or onRequest in Java) that identifies the site ID for the domain the user is requesting. In literally dozens of other frameworks this type of thing is painless (e.g. Django), but I'm learning that the session object in Play is apparently immutable, however.
So, right now, I have something like this:
override def onRouteRequest(request: RequestHeader): Option[Handler] = {
if (request.session.get("site").isEmpty){
val id = models.Site.getSiteUIDFromURL(request.host.toLowerCase()).toString()
if (!id.isEmpty){
//what goes here to set the session?
}else{
//not found - redirect to a general notFound page
}
}
super.onRouteRequest(request)
}
And, although it's not the most efficient way using a database lookup, it works for testing right now. I need to be able to set a session key in the global but am completely lost on how to do that. If there are any better methods I am all ears (perhaps wrapping my controllers?).
I'm open to solution examples in either Java or Scala.
Think of actions in Play as being function calls, the input is the request, the output is the result. If you want to change the result of a wrapped function call, then you must first invoke the function, and then apply your change. Adding a key to a session is changing the result, since the session is sent to the client in the session cookie. In the code above, you're trying to do the change before you have a result to change, ie, before you call super.onRouteRequest.
If you don't need to modify routing at all, then don't do this in onRouteRequest, do it in a filter, much easier there. But assuming you do need to modify routing, then you need to apply a filter to handler returned. This is what it might look like:
override def onRouteRequest(request: RequestHeader): Option[Handler] = {
val maybeSite: Option[String] = request.session.get("site").orElse {
// Let's just assume that getSiteUIDFromUrl returns Option[String], always use Option if you're returning values that might not exist.
models.Site.getSiteUIDFromURL(request.host.toLowerCase())
}
maybeSite.flatMap { site =>
super.onRouteRequest(request).map {
case e: EssentialAction => EssentialAction { req =>
e(req).map(_.withSession("site" -> site))
}
case other => other
}
}
}
Check the source code for the CSRFFilter to see examples of how to add things to the session in a filter.

Redirect with anchor in play 2

I'm looking for possibility to add anchor to url returned in controller:
public static Result open(String id) {
// here I want to add acnhor like #foo to the produced url
return redirect(routes.MyPage.show(id));
}
I found that it was possible in play 1 using addRef method, but I couldn't find any replacement of the method in play 2.
Of course I can use concatenation like:
public static Result open(String id) {
// here I want to add acnhor like #foo to the produced url
return redirect(routes.MyPage.show(id).url + "#foo");
}
But it seems ugly.
Thank you for any help! Have a good day!
Before trying to answer that question.
I should recommend you change whatever behavior you're currently setting.
Because, an URL fragment's purpose is client side only. Such fragment is never sent to the server, so that it's cumbersome to do the opposite.
However, here is the embryo of a (quite?) elegant solution that you could follow.
What I'll try to do is to leave the browser deal with the fragment, in order to keep potential behaviors (f.i. go to ID or even deal with history...).
To do so, you could add an implicit parameter to your main template which will define the fragment that the URL should have:
#(title: String)(content: Html)(urlFragment:Option[UrlFragment] = None)
As you can see I wrapped the parameter in an Option and default'ed it to None (in order to avoid AMAP pollution).
Also, it simply wraps a String but you could use String alone -- using a dedicated type will enforce the semantic. Here is the definition:
case class UrlFragment(hash:String)
Very simple.
Now here is how to tell the browser to deal with it. Right before the end of the head element, and the start of body, just add the following:
#urlFragment.map { f =>
<script>
$(function() {
//after everything is ready, so that other mechanism will be able to use the change hash event...
document.location.hash = "#Html(#f.hash)";
});
</script>
}
As you can see, using map (that is when the urlFragment is not None) we add a script block that will set the hash available in urlFragment.
This might be a start, however... Think about another solution for the whole scenario.
As of Play 2.4, it's possible to use Call.withFragment().
routes.Application.index.withFragment("some-id").absoluteURL(request)
This was added by PR #4152.

How do I create with Java a well formatted request to publish on Wordpress with XML-RPC?

I've found this guide on internet to publish on Wordpress using XML-RPC inside my Java Project, for example I want a message on my Blog, every time it's specified date.
http://wordpress.rintcius.nl/post/look-how-this-wordpress-post-got-created-from-java
Now, I've followed the guide and I'm trying to let it run but I don't understand yet how exactly parameters for my post works.
For example using the method blogger.NewPost I call:
public Integer post(String contents) throws XmlRpcException {
Object[] params = new Object[] {
blogInfo.getApiKey(),
blogInfo.getBlogId(),
blogInfo.getUserName(),
blogInfo.getPassword(),
contents,
postType.booleanValue()
};
return (Integer) client.execute(POST_METHOD_NAME, params);
}
and my "contents" value is:
[title]Look how this wordpress post got created from java![/title]"
+ "[category]6[/category]"
+ FileUtils.getContentsOfResource("rintcius/blog/post.txt");
(I'm using "[" instead of "<" and "]" instead of ">" that are processed by stackoverflow)
Now, how could I use all parameters in this XML way?
Parameters here: http://codex.wordpress.org/XML-RPC_MetaWeblog_API#metaWeblog.newPost
And, it's the content only a "string" without any tag?
Thanks a lot to all!
Still don't know why it gives me back errors but i think it's only a bit outdated.
Found this other libraries that works perfectly
http://code.google.com/p/wordpress-java/
I advice all to use this since the other one is outdated
Thanks all

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