org.springframework.web.util.NestedServletException: Request processing failed; nested exception is java.lang.NullPointerException in REST with Spring

Question

I am trying to create REST service using Spring.When I try to access that service it returns proper data but shows -

Exception handling request to /RESTServ         


        

Answer 1

We faced this issue while trial to migrate spring-boot-1.2.2-Final on wildfly 8.1.0-Final to spring-boot-1.3.2-Final on wildfly 8.1.0-Final. This error does not occur on wildfly 8.2.1-Final, so if you have option tp udate your wildfly version, you should do that.

But if you still have to use wildfly-8.1.0-Final, then you could patch it.

1) get https://github.com/undertow-io/undertow/archive/1.0.15.Final.zip

2) edit io.undertow.servlet.spec.HttpServletResponseImpl located in module servlet

@Override
public String getHeaders(final String name) {
    return new ArrayList(exchange.getResponseHeaders().get(name));
}

to

@Override
public Collection getHeaders(final String name) {
    final HeaderValues headerValues = exchange.getResponseHeaders().get(name);
    if (headerValues != null) {
        return new ArrayList(headerValues);
    }
    return new ArrayList();
}

Add the HeaderValues import:

import io.undertow.util.HeaderValues;

package undertow-servlet with maven and then overwrite

{wildfly-root-directory}/modules/system/layers/base/io/undertow/servlet/main/undertow-servlet-1.0.15.Final.jar

with the file

{undertow-root-directory}/servlet/target/undertow-servlet-1.0.15.Final.jar

This will solve this error.