Why would “java.lang.IllegalStateException: The resource configuration is not modifiable in this context.” appear deploying Jersey app?

Question

I have created an app implementing REST services locally using:

Eclipse Indigo Jersey 2.4 Tomcat 7.0.47

When running locally using Eclipse, the services work

Answer 1

I got the same error message. For me the problem was, that I used @RequestMapping (a Spring annotation) instead of the @QueryParam (JAX-RS annotation) on a method argument due to a copy paste. The error message was not that informative, but that was the problem for me.

Answer 2

The issue in my case is that the shaded jar did not include the javassist package that Jersey uses to do bytecode manipulation. When shading a jar, make sure to include org.javassist:*.

    <dependency>
        <groupId>org.javassist</groupId>
        <artifactId>javassist</artifactId>
        <version>3.26.0-GA</version>
    </dependency>

Answer 3

I solved this problem by adding this code into web.xml file

  <servlet>
    <servlet-name>jersey-serlvet</servlet-name>
    <servlet-class>
        com.sun.jersey.spi.container.servlet.ServletContainer
    </servlet-class>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>jersey-serlvet</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>

Answer 4

In my case, I had a Jersey POST resource for file uploads. The resource specified the parameter: @FormDataParam("file") InputStream file

and consumed MediaType.MULTIPART_FORM_DATA.

To fix the issue, I had to add the following to the Jersey REST configuration in my web.xml file:

<init-param>
    <param-name>jersey.config.server.provider.classnames</param-name>
    <param-value>org.glassfish.jersey.media.multipart.MultiPartFeature</param-value>
</init-param>

Answer 5

In my case it was just a missing @PathParam("id") for the 'int id' declaration. Wrong code:

@POST
@Path("{id}/messages")
public Response returnMessages(int id, Message[] msgs) {

Corrected code:

@POST
@Path("{id}/messages")
public Response returnMessages(@PathParam("id") int id, Message[] msgs) {

Answer 6

Add

<build>
  <resources>
    <resource>
      <directory>src/main/resources</directory>
      <filtering>true</filtering>
    </resource>
  </resources>
</build>