Access to request().query().get() raises UnsupportedOperationException

[io7m]

Environment Details

• Helidon Version: 4.0.0-RC1
• Helidon SE
• JDK version:

openjdk version "21" 2023-09-19
OpenJDK Runtime Environment (build 21+35)
OpenJDK 64-Bit Server VM (build 21+35, mixed mode, sharing)

• OS: Linux

---

Problem Description

The Javadoc for the io.helidon.common.uri.UriQuery interface's get method says:

    /**
     * Get the first value.
     *
     * @param name name of the parameter
     * @return first value
     * @throws NoSuchElementException in case the name is not present
     */
    String get(String name) throws NoSuchElementException;

Unfortunately, the implementation of UriQueryEmpty has:

  @Override
  public String get(String name) {
      throw new UnsupportedOperationException("Empty query");
  }

This means you'll get an UnsupportedOperationException instead of the expected NoSuchElementException if you're trying to get a parameter from a query that didn't contain any parameters.

Steps to reproduce

Just try calling ServerRequest.query().get("x") for any incoming query that has no parameters.