[JAVA]io.swagger.client.ApiException: Not Found

I have encounter this error when ever a respond code 404 returns.
Please advice on the following errors.

<-- HTTP/1.1 404 Not Found (444ms)
Date: Wed, 14 Nov 2018 07:10:58 GMT
Content-Type: application/json
Transfer-Encoding: chunked
OkHttp-Sent-Millis: 1542179458658
OkHttp-Received-Millis: 1542179458870

{"errors":[{"code":"404","message":"Entity not found."}]}
<-- END HTTP (57-byte body)
io.swagger.client.ApiException: Not Found
        at io.swagger.client.ApiClient.handleResponse(ApiClient.java:925)
        at io.swagger.client.ApiClient.execute(ApiClient.java:841)
        at io.swagger.client.api.EntitiesApi.outboundDataEntitiesWithHttpInfo(EntitiesApi.java:191)
        at uen.apex.UenApexConnector.getEntities(UenApexConnector.java:423)
        at uen.apex.UenApexConnector.main(UenApexConnector.java:103)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)
Exception in thread "main" java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)
        at org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader.main(JarRsrcLoader.java:58)

Swagger-codegen version

2.3.1 (current stable)

Swagger declaration file content or url

Command line used for generation

java -jar modules/swagger-codegen-cli/target/swagger-codegen-cli.jar generate
-i inputfile.yaml
-l java\

Steps to reproduce

Whenever a 404 status code is return

Related issues/PRs

Suggest a fix/enhancement

Start with ApiClient.handleResponse(ApiClient.java:925) and the generated EntitiesApi.outboundDataEntitiesWithHttpInfo call shown in the stack trace. Reproduce the 404 using the supplied inputfile.yaml and generated Java client, then clarify whether the reported exception is expected or what alternative handling is required; the issue does not currently define a fix or completion condition.