Why isn't Jersey allowing same rest urls with different HttpMethods?

Question

API to get a customer :

@Path("/{customerId}")
@GET
@Consumes({"application/json"})
@Produces({"application/json"})

API to update a customer :

@Path("/{customerId}")
@PUT
@Consumes({"application/json"})
@Produces({"application/json"})

API to delete a customer :

@Path("/{customerId}")
@DELETE
@Consumes({"application/json"})
@Produces({"application/json"})

Note : The same apis in my spring boot project work fine.

In my Java EE application (i don't have much experience working on EE though), I am getting weird exceptions when I add these apis :

[#|2019-01-24T18:00:25.698+0530|SEVERE|oracle-glassfish3.1.2|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=419;_ThreadName=http-thread-pool-8080(3);|WebModule[]StandardWrapper.Throwable
com.sun.jersey.spi.inject.Errors$ErrorMessagesException
    at com.sun.jersey.spi.inject.Errors.processErrorMessages(Errors.java:170)
    at com.sun.jersey.spi.inject.Errors.postProcess(Errors.java:136)
    at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:199)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:771)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:766)
    at com.sun.jersey.spi.container.servlet.ServletContainer.initiate(ServletContainer.java:488)
    at com.sun.jersey.spi.container.servlet.ServletContainer$InternalWebComponent.initiate(ServletContainer.java:318)
    at com.sun.jersey.spi.container.servlet.WebComponent.load(WebComponent.java:609)
    at com.sun.jersey.spi.container.servlet.WebComponent.init(WebComponent.java:210)
    at com.sun.jersey.spi.container.servlet.ServletContainer.init(ServletContainer.java:373)
    at com.sun.jersey.spi.container.servlet.ServletContainer.init(ServletContainer.java:556)
    at javax.servlet.GenericServlet.init(GenericServlet.java:244)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1453)
    at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:1093)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:189)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
    at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
    at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
    at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
    at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
    at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
    at com.sun.grizzly.arp.DefaultAsyncExecutor.execute(DefaultAsyncExecutor.java:159)
    at com.sun.grizzly.arp.DefaultAsyncExecutor.interrupt(DefaultAsyncExecutor.java:145)
    at com.sun.grizzly.arp.AsyncProcessorTask.doTask(AsyncProcessorTask.java:102)
    at com.sun.grizzly.http.TaskBase.run(TaskBase.java:193)
    at com.sun.grizzly.http.TaskBase.execute(TaskBase.java:175)
    at com.sun.grizzly.arp.DefaultAsyncHandler.handle(DefaultAsyncHandler.java:145)
    at com.sun.grizzly.arp.AsyncProtocolFilter.execute(AsyncProtocolFilter.java:210)
    at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
    at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
    at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
    at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
    at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
    at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
    at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
    at java.lang.Thread.run(Thread.java:745)

And

[#|2019-01-24T18:00:25.698+0530|WARNING|oracle-glassfish3.1.2|javax.enterprise.system.container.web.com.sun.enterprise.web|_ThreadID=419;_ThreadName=http-thread-pool-8080(3);|StandardWrapperValve[org.netbeans.rest.application.config.ApplicationConfig]: PWC1382: Allocate exception for servlet org.netbeans.rest.application.config.ApplicationConfig
com.sun.jersey.spi.inject.Errors$ErrorMessagesException
    at com.sun.jersey.spi.inject.Errors.processErrorMessages(Errors.java:170)
    at com.sun.jersey.spi.inject.Errors.postProcess(Errors.java:136)
    at com.sun.jersey.spi.inject.Errors.processWithErrors(Errors.java:199)
    at com.sun.jersey.server.impl.application.WebApplicationImpl.initiate(WebApplicationImpl.java:771)

Any help/explanation is appreciated.

Answer 1

To configure REST api endpoint in Java EE, create a class and call it RestAppConfig, or RestApplicationConfig, the naming does not matter, and have the following in the code:

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;

@ApplicationPath("/api")
public class RestAppConfig extends Application {

}

The class can be empty.

Then create a class which will define all the api methods:

import javax.ws.rs.GET;
import javax.ws.rs.Consumes;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.Path;
import javax.ws.rs.core.Response;

@Path("customer")
public class MyAPI {

    @Path("{customerId}")
    @GET
    @Produces({"application/json"})
    public Response getCustomer(@PathParam("customerId") int customerId){
    ... 
    //define your other methods here
}

Then your api methods will be accessible through: /context/api/customer/{customerId}

Jersey definitely allows multiple different Http methods to access the same URL.

If it's still not working or you already had this configuration, try to delete two of the methods so that you only have one left, and try to test it again, does it give you the same exceptions? Then the problem might be related to the server or the implementation, try to replace your Jersey dependency in your pom.xml.

Also, by convention, GET methods should not consume anything, while PUT and DELETE methods should not produce anything.