I'm looking for a better way to structure my rest client/rest api code. Currently, I have my rest api with routes like:
get /book
The literal string "/book" is defined on the server side, and on the client side, I have to use the same literal string exactly.
What I would like to do is, have a file serverside which has all of my routes in it, and send it to the client as json, which the client uses for routing.
The basic workflow would be:
Start the server
When the client connects, make a get request for the routes object
return an object like this:
{
getBook:"/book",
createBook:"/book/create"
}
that way my client can use the object returned for the routes instead of hard coding them.
Is this a good idea?
Related
In my server, which is using akka http, I'd like to mark certain routes with an attribute, or a custom HTTP request header, that is accessible to downstream processing of that request. How can I do this? I see how to extract the request, but I don't see how to modify that request in a way that is passed along.
For example, my route might be something like
val route = (get & path("yay") {
complete(...the actual processing of the route...)
}
and I'd like to mark this route with a property (attribute, request header, etc) accessible to "the actual processing of the route".
(I'm highly simplifying my example. In my real code, that route processing is not something I could just simply pass, say, a value directly in this block of code. So, I was thinking of being able to mark the request itself in some fashion.)
You can use mapRequest for modifying the HttpRequest:
val route = mapRequest(...modifying the request...) {
complete(...the actual processing of the route...)
}
I am working on a REST backend consumed by a javascript/ajax front-end.
I am trying to find a way to deal with invalid requests sent over by the front-end to the backend.
One of the issues I have is that HTTP status codes such as (400, 409) are not fine-grained enough to cover business logic errors such as passwords not matching (in the case of a user changing his password) or an email being unknown to the system (in the case of a user trying to signin with the application).
I am thinking of using HTTP response headers in order to communicate server-side error from the backend to the front-end.
I could for instance have an Error enum (or a class with constants) as follows:
public enum Error {
UNKNOWN_EMAIL,
PASSWORDS_DONT_MATCH,
//etc.
}
I would then use that enum in order to set the headers on the response as follows:
response.setHeader(Error.UNKNOWN_EMAIL.name(), "true");
... and deal with the error appropriately on the front-end.
Can the above architecture be improved? If so how?
Is my usage of HTTP response headers correct?
Should I use constants or enums?
Is my usage of HTTP response headers correct?
I do not think it is incorrect, however I prefer to send an error message/code directly back in the response body. This is usually more convenient for the client to access and is more explicit. As part of consuming each response, the client can check the contents of the errors (you may have multiple) and act accordingly. The following is a little contrived just to provide an example:
// ...
{
"errors": {
"username": "not found"
"password": "no match"
}
"warnings": {
"account": "expired"
}
}
// ...
The above is quite a simple approach - your JSON message can be as sophisticated as you wish but keep in mind that you should only expose the information the client needs for it to achieve its goal. This will also depend on whether you are publishing an API for 3rd parties/public consumption or whether its just for your own clients ie. your own website. If you have other parties consuming it then put some thought into it since once you publish it then you need to maintain it that way - otherwise you break any consumers.
Check out JSON API for some standardized guidance on handling errors.
Should I use constants or enums?
Since these are a related set of properties an enum is preferable over constants (I assume you are using Java).
I need to create a ReST service using Jersey 2.0. I need to send multiple documents and metadata to the client.
What is the best approach do to the achieve this.
I was able to send a MultiPart response from the server , but not sure how to read this from the client code
Let's say you have a document called "document1" which you want to get via your client.
In your REST-API your unique identifier for the document (the resource) could be:
http://example.com/restapi/documents/document1
As you want to READ data you do a HTTP-GET Request to that uri.
And here comes the important part for you: A resource can have multiple representations - meta data and binary data in your case.
So the client has to tell the server which representation type to get (content negotiation). This information can be set in the ACCEPT Header of the client request for instance.
You can use the content type "application/json" as a representation for the meta data.
Unfortunately you didn't tell us what kind of binary data you want to send.
If they are PDFs the content type would be "application/pdf" for instance. If the binary data doesn't have a specific type you can use "application/octet-stream".
Of course there is work to be done on the server side too. Here an example:
#Path("/documents/{documentname}")
public class docResource {
#GET #Produces("application/json")
public Response getDocumentMetaData(#PathParam("documentname") String docName) {
// Create a Response containing a json
}
#GET #Produces("application/pdf")
public Response getDocumentBinaryData(#PathParam("documentname") String docName) {
// Create a response containing the binary data
}
...
}
Jersey will check the accept header of the client and will run the appropriate method.
Also see: https://jersey.java.net/documentation/latest/jaxrs-resources.html
If you are using jersey with jackson you can also easily marshal a POJO to JSON and visa versa:
http://examples.javacodegeeks.com/enterprise-java/rest/jersey/json-example-with-jersey-jackson/
If you are not sure what to do in the "getDocumentBinaryData"-Method - checkout this simple example from mkyong:
http://www.mkyong.com/webservices/jax-rs/download-excel-file-from-jax-rs/
I need to do a post request from a gwt app to a server. So far this works fine. However, originally I used an object that contained all the parameters send over to the server via a rpc request so I did not have to manage the serialization and deserialization myself. Now I send this stuff via a post request and on the server side I get something like username=blabla&location=blabla
I'd rather like to do something like this (pseudo code):
String serializedObject = parameterObject.serialize();
sendPostRequestWithContent(serializedObject);
and on the server side:
doPost(...)
String serializedObject = request.getContent();
ParameterObject parameterObject = ParameterObject.deserialize( serializedObject );
Any idea how I could do this?
There are different ways.
For simple objects manually serialize and deserialize (field1=123123&field2=1232)
Use JSON as payload.
For solution 2 you can use a JSON parser on the beackend (Jackson, Gson, etc) and on the client you can either manually serialize the object to JSON or one of these methods.
In BizTalk 2006, I am trying to set up a messaging-only scenario whereby the recieved message (a string) is passed to a web service method that takes a single string parameter. In other words, the whole body of the BizTalk message should be passed as the parameter to the web service call.
The service method looks like this:
[WebMethod]
public void LogAuditEvent(string auditEventMessage)
I have set up the assembly with the proxy class in the SOAP adapter configuration as required, but I can't figure out how to get the message body to be passed as the parameter. Without doing anything special, I get the following error message:
Failed to serialize the message part
"auditEventMessage" into the type
"String" using namespace "".
I think this means that the adapter cannot find a message part named after the parameter. So, my question is what do I need to do to get my message set up correctly? I was thinking that maybe I needed to add an outbound map, but was not sure what to use as the source schema and how to generate a proper schema for the web service request message.
Does anyone have any pointers on this seemingly simple task?
Thanks.
TDL,
I would take a look at the links below for some tips on how to do this. SOAP adapter can be problematic I would recommend WCF if your using R2. And if not look at the WSE adapters as well.
http://blogs.digitaldeposit.net/saravana/post/2007/01/31/Calling-Web-Service-from-BizTalk-2006-in-a-Messaging-only-Scenario-(aka-Content-based-Routing).aspx
-and-
http://www.pluralsight.com/community/blogs/aaron/archive/2005/10/07/15386.aspx
-and-
http://social.technet.microsoft.com/Forums/en-US/biztalkgeneral/thread/92f2cad3-39b9-47d0-9e6f-011ccd2f9e10/
-Bryan