Develop Reference

Passing array with in GAE Endpoints

I am just trying out the first example of GAE Endpoints, I modified the sample API Method to resemble this.
#ApiMethod(name = "sayHi")
public MyBean sayHi(#Named("name") String[] names) {
My expectation is to receive a array of strings.
Now when I use the Google API Explorer to test this, [https://apis-explorer.appspot.com/apis-explorer/]
it generates API like this
POST https://myprojectid.appspot.com/_ah/api/myApi/v1/sayHi/arg1/arg2/arg3?fields=data
It eventually returns 404 error. Since the endpoint is not recognized.
What am I doing wrong here? In fact explorer shows name as String not String[]. Any help is appreciated!

First things first: does this work when there is a single String parameter? There's some servlet mapping magic that needs to happen to expose endpoints, and if that is not present in the project, things won't work. See this link to make sure your web.xml is as it should be.
Looking at this link, it seems that if your method parameter is a basic type (not a real Java object), and if it is not specifically included in a #Path annotation, there's some uncertainty in what will happen in your Api:
Path parameters are the method parameters included in the path property of the #ApiMethod annotation. If path is unspecified, any parameters not annotated with #Nullable or #DefaultValue will be automatically added to the path (they will be path parameters).
So it seems that by not including "name" in a #Path annotation, the docs don't state what the format of the path will be. The generated descriptor that the Explorer is looking at seems to think the right answer is /names[0]/names[1]/names[2], kind of like C-style varargs. It might be this disconnect that causes your 404 to happen. Can you try by including "name" in a #Path annotation?

Instead of having an array as a parameter of the endpoint method, you should put an object (java bean) which contains an array as a property.
Then you get the object in your method and you just read the property and treat it as an array.
Edit after some more research, following your comment
Indeed when you try to pass an array as a Path parameter it doesn't work. The different elements of your array are added to the URL (as you show in your question) and it generates a 404 Not Found error. The trick is that you should pass this array as a Query parameter and not a Path Parameter. See this doc: https://cloud.google.com/appengine/docs/java/endpoints/parameter-and-return-types#path_parameters
And indeed, if you do something like that it works very well:
#ApiMethod(name = "sayHi",
path = "sayHiWithName")
public MyBean sayHi(#Named("name") String[] names) {
MyBean response = new MyBean();
response.setData("Hi, " + names[0] + names[1]);
return response;
}
Note that the parameter is NOT added to the path (i.e. we don't have a path like sayHiWithName/{name}).

Can we have more than one #Path annotation for same REST method [duplicate]

This question already has answers here:
JAX-RS: Multiple paths
(4 answers)
Closed 2 years ago.
Can we have more than one #Path annotation for same REST method i.e. the method executed is the same, but it is executed on accessing more than one URL?
E.g.: I want to run the searchNames() method on both http://a/b/c and http://a/b.

You can't have mutliple #Path annotations on a single method. It causes a "duplicate annotation" syntax error.
However, there's a number of ways you can effectively map two paths to a method.
Regular expressions in #Path annotation
The #Path annotation in JAX-RS accepts parameters, whose values can be restricted using regular expressions.
This annotation:
#Path("a/{parameter: path1|path2}")
would enable the method to be reached by requests for both /a/path1 and /a/path2. If you need to work with subpaths, escape slashes: {a:path1\\/subPath1|path2\\/subPath2}
Serving responses with a redirection status code
Alternatively, you could set up a redirection. Here's a way to do it in Jersey (the reference implementation of JAX-RS), by defining another subresource. This is just an example, if you prefer a different way of handling redirections, feel free to use it.
#Path("basepath")
public class YourBaseResource {
//this gets injected after the class is instantiated by Jersey
#Context
UriInfo uriInfo;
#Path("a/b")
#GET
public Responce method1(){
return Response.ok("blah blah").build();
}
#Path("a/b/c")
#GET
public Response method2(){
UriBuilder addressBuilder = uriInfo.getBaseUriBuilder();
addressBuilder.path("a/b");
return Response.seeOther(addressBuilder.build()).build();
}
}
Using a servlet filter to rewrite URLs
If you're going to need such functionality often, I suggest intercepting the incoming requests using a servlet filter and rewriting the paths on the fly. This should help you keep all redirections in one place. Ideally, you could use a ready library. UrlRewriteFilter can do the trick, as long as you're fine with a BSD license (check out their google code site for details)
Another option is to handle this with a proxy set up in front of your Java app. You can set up an Apache server to offer basic caching and rewrite rules without complicating your Java code.

As explained in Tom's answer, you can not use more than one #Path annotation on a single method, because you will run into error: duplicate annotation at compile time.
I think the simplest way to get around this is to use method overloading:
#Path("{foo}")
public Response rest(#PathParam("foo") final String foo) {
return this.rest(foo, "");
}
#Path("{foo}/{bar}")
public Response rest(#PathParam("foo") final String foo,
#PathParam("bar") final String bar) {
return Response.ok(foo + " " + bar).build();
}
You could also use more different method names if you run into the case where multiple overloaded methods have the signature.

Another solution for your particular example:
http://a/b/c
http://a/b
Let's suppose that:
/a is for the resource class
/b/c and /b are the paths for the methods
because a full path looks like:
<protocol><host><port><app><url-pattern><resource-path><method-path>.
Use optional parameter
#Path("/b{c : (/c)?}")
public Response searchNames(#PathParam("c") String val) {
...
}
The example above works for all examples like:
/b
/b/
/b/c
/b/c/
but when c is provided, the val is /c (it has a / before).
If you want to fix the problem above (to avoid Java parsing), you need something more complex:
#Path("/b{slash : (/)?}{c:((?<=/).*)?}")
which will return only c (not /c) for the 3rd bullet point, but for the 4th bullet point it will return c/ which has to be parsed in Java.
But for your case ("the method executed is the same"), don't worry about parsing because you don't have different actions.

If you are using Spring then try
#RequestMapping(value = {"/def", "/abc"}, method = RequestMethod.POST)
This will work for both /abc and /def.
– sSaroj Nov 17 '17 at 10:13

Validation of method parameters

I have a RESTful web service. For implementation using JAX-RS (Jersey).
Have the following method:
public void foo (#PathParam ("name") String uuid) {
...
}
I need to do validation of input parameters. And if data invalid throw WebApplicationException.
I added my custom annotation CheckUuid (extends ):
public void foo (#PathParam ("name") #CheckUuid String uuid) {
...
}
Is it possible to do validation using annotations on a stage when the method chosen, but not yet called? For example using PreProcessInterceptor?

Java EE6 has some built in validation functionality.
http://docs.oracle.com/javaee/6/tutorial/doc/gircz.html
I have not used it however, but I saw it brought up during Java One and it looks pretty cool.
I'm not sure at what point this would happen, but I think it might work out for you.

As a result, it was decided to use the standard pattern in the method validation. Because in Jersey do not have PreProcessInterceptor.

Renaming the argument name in JAX-WS

I created a web service using JAX-WS in RSA 7.5 and Websphere 7 using bottom-up approach. When I open the WSDL in SOAP UI, then the arguments section is appearing like this:
<!--Optional-->
<arg0>
<empID>?</empId>
</arg0>
<!--Optional-->
<arg1>
<empName>?</empName>
</arg1>
<!--Optional-->
<arg2>
<empAddress>?</empAddress>
</arg2>
<!--Optional-->
<arg3>
<empCountry>?</empCountry>
</arg3>
The service method takes the above 4 elements as the parameters to return the employee details.
1) I want to rename this arg0, arg1, and so on with some valid names.
2) I want to remove the <!--optional--> present above the arg tags. (For removing the <!--optional--> from elements name, I used #XMLElement(required=true)). But I am not sure where exactly to use this annotation in this case :(
Please help.
Regards,

You put the #XMLElement(required=true) above the variables in your class that are being returned from your service. I just learned about that option about a month ago. So right above where you declare empName put the tag and required.
To rename the parameters of your service use the #WebParam(name="<name you want in soap>") in front of each input variable to the service.
For example, if you have a service method called get(String name) it would look something like get(#WebParam(name = "name") String name)
You are correct, now that I read your comment again. The services I support use Objects in the input and output, which is why I put the XMLElement tag in the class of those objects.
You need to put the tag in the class that declares your variables that are passed in or returned to the service. If those happen to be declared in your service class that is fine. The main point is that you put that XMLElement tag above the variable declaration, versus putting it on a getter or setter.
This tutorial shows some examples of the usage. JAXB tutorial

Webservice problem - methods can't take more than 1 parameter

I'm using IntelliJ IDEA 8 and Axis to set up a webservice that's deployed on Tomcat5.5. The generated wsdl looks like this: http://track.priskick.se/Tracker.wsdl
A method is declared as
public void storeImpressionReport(int siteId, int adId, int zoneId, int count,
int excludeCount) { ... }
and exposed in the webservice. Next, I build the client (also Java) using Axis, but as a runtime call to the method is made with the parameters 0,0,0,0,0, I get this:
Tried to invoke method public void com.xxxxx.xxxx.xxxx.xxxxx.storeImpressionReport(int,int,int,int,int) with arguments java.lang.Integer,null,null,null,null. The arguments do not match the signature.; nested exception is: java.lang.IllegalArgumentException
Reducing the number of parameters of the method to 1 makes it work, however this feels like a pretty silly limitation and strange behaviour. Please help me if you know what might be wrong here - why can't I expose methods and have them take more than one parameter?
=== UPDATE
I now tried generating the client java using wsdl generated from IntelliJ instead of calling the service with the ?wsdl option. This wsdl keeps the correct parameter names, maybe because the generator has access to the source. Now I get
No such operation 'siteId'
AxisFault
These are the relevant files:
http://track.priskick.se/Tracker/TrackerSoapBindingStub.java
http://track.priskick.se/Tracker/TrackerServiceTestCase.java
http://track.priskick.se/Tracker/Tracker_PortType.java
http://track.priskick.se/Tracker/TrackerService.java
http://track.priskick.se/Tracker/TrackerServiceLocator.java
the wsdl used for the client is found at
http://track.priskick.se/Tracker.wsdl
the service is found at
http://stage.klikki.com/services/Tracker
Cheers
Marcus Johansson

Oh the joy. I changed the service style to WRAPPED, and this seems to have solved the problem.