We Keep Coding

Spring boot application which method will be called with no path

I am trying a simple spring boot application. Here is my code. So when I run it is calling sayHello() why?
#RestController
public class HelloController {
#RequestMapping()
public String sayHello2(){
return "Hello2";
}
#RequestMapping(produces = { "text/html" })
public String sayHello(){
return "Hello";
}
}

It depends from where you are calling the api. When you call from browser where default format is text/html hence it calls sayHello. Try calling using curl, it will call sayHello2

It depends on your request header. If the request header has Accept text/html (usually from browsers), the corresponding request is executed. As #pvpkiran pointed out, try curl or alter the Accept header to see differences.

You are not providing the URL pattern both the method is sharing same
mapping as you have not mentioned over there i.e. "/".
#RestController
public class HelloController {
#RequestMapping(value="/")
public String sayHello2(){
return "Hello2";
}
#RequestMapping(value="/hello",produces = { "text/html" })
public String sayHello(){
return "Hello";
}
}
now when u enter / it will execute sayHello2(),and when URL pattern is /hello it will execute sayHello().

Finding a method exists in rest service or not in Java

Hi i am new to Rest Service in Java. First i want to explain my problem and then at the end i will be asking question.
I am using Mozilla rest CLIENT. My rest class looks like:
#Path("/api1")
public class RestService {
#POST
#Path("/v1")
#Consumes("application/json")
#Produces("application/json")
public String v1(String json){
//Some code here
}
#POST
#Path("/v2")
#Consumes("application/json")
#Produces("application/json")
public String v2(String json){
//Some code here
}
}
Now in this code i have two functions.
To access v1, call will be:
http://localhost:8080/project_name/package/api1/v1
To access v2 call will be:
http://localhost:8080/project_name/package/api1/v2
Question:
Now in my rest service class i want to add a patch of code which detects that whether any function which has been called either v1,v2 or v3 exists in this service or not?
Can i do this? Or anyother way to do this?
Thanks

Well, you could add a wildcard response:
#POST
#Path("/{what}")
#Consumes("application/json")
#Produces("application/json")
public String v2(String json, #PathParameter("what") String what){
return "The path "+what+" does not exist.";
}
However, since the user will never see the direct responses, you can answer with a customized 404:
#POST
#Path("/{what}")
#Consumes("application/json")
#Produces("application/json")
public Response v2(String json, #PathParameter("what") String what){
return Response.status(Status.NOT_FOUND).entity("The path "+what+" does not exist.");
}
This way you can also detect on the client side when something is incorrect.

The best approach for you is to add a fallback response. That will be called when somebody tries to access any non existing WS method.
#RequestMapping(value = {"*"})
public String getFallback()
{
return "This is a fallback response!";
}

is it possible to call one jax-rs method from another?

suppose i have some jax-rs resource class:
#Consumes(MediaType.APPLICATION_JSON)
#Produces(MediaType.APPLICATION_JSON)
public class ResourceA {
#GET
public Something get(#Context UriInfo uriInfo) {
if (...) {
//how to get to ResourceB ?
}
}
}
and i want to conditionally redirect the call to some other jax-rs resource:
public class ResourceB {
#GET
#Path("{identifier}")
public Other get(#PathParam("identifier")String someArg) {
}
}
how do i do this?
note that i dont want this to be visible to the client (so no http redirects) and generally the resource methods i want to redirect to dont share the same signature (they may have path params etc as in the example i gave).
im running jersey 2.6 under apache tomcat (its a spring app, if thats any help)
EDIT - im looking for a jax-rs equivalent of servlet forward. i dont want to do an extra http hop or worry abour instantiating resource classes myself

You can get it using ResourceContext as follows:
#Context
ResourceContext resourceContext;
This will inject the ResourceContext into your Resource. You then get the resource you want using:
ResourceB b = resourceContext.getResource(ResourceB.class);
The Javadoc for ResourceContext is here. You can find a similar question here

I'm not aware of any possibility to do this from a resource method, but if it fits your use case, what you could do is implement your redirect logic in a pre matching request filter, for example like so:
#Provider
#PreMatching
public class RedirectFilter implements ContainerRequestFilter {
#Override
public void filter(ContainerRequestContext requestContext) {
UriInfo uriInfo = requestContext.getUriInfo();
String prefix = "/redirect";
String path = uriInfo.getRequestUri().getPath();
if (path.startsWith(prefix)) {
String newPath = path.substring(prefix.length());
URI newRequestURI = uriInfo.getBaseUriBuilder().path(newPath).build();
requestContext.setRequestUri(newRequestURI);
}
}
}
This will redirect every request to /redirect/some/resource to /some/resource (or whatever you pass to requestContext.setRequestUri()) internally, before the resource method has been matched to the request and is executed and without http redirects or an additional internal http request.

How to get xml produced from jax-rs?

I would like to log the xml produced from this. How can I do this ?
#GET
#Path("add")
#Producse("application/xml")
public List<String>getCustomerList(....) {
}
}
UPDATE
why i need this is because , I want to have database logging with the request and response header, body etc

Not sure what you mean by log -- do you mean display on a web page?
So assuming the CustomerList is annotated and the Customer class is also annotated and each has getters and setters.
#GET
#Path("add")
#Produces(MediaType.APPLICATION_XML)
public Response returnListOfCustomers() {
CustomerList returnMe = this.getMyCustomerList(); // <-- Made this method up
return Response.ok(returnMe).build()
}
This is assuming you are trying to create a Restful service: JAX-RS.

jersey is not finding my resource with sub url

I want to have two resources at URLs: /apps and /apps/runs.
So, I created resources as shown below. I use Spring for object injection. When I use this way, I am getting the 404 error for HTTP get requests on /apps/runs. Am I doing some thing wrong?
Here is my code:
#Scope("prototype")
#Path("/apps")
public class ManufacturersResource {
#GET
#Produces("application/xml")
public List<Applications> getApplications() {
return apps.findAll();
}
}
#Scope("prototype")
#Path("/apps/runs")
public class ManufacturersResource {
#GET
#Produces("application/xml")
public List<ApplicationInstances> getApplicationInstances() {
return appInstances.findAll();
}
}

Jersey won't allow you to have two files share a common prefix, if one is using the prefix as an entire resource url.
So you can move both methods inside the same file, or have /apps be something else like /apps/list