java: Parameter keys are not escaped properly

Created by: lorenzleutgeb

Description

Note the | character in the parameter key. This translates to:

  public static final String SERIALIZED_NAME_UPDATED_AT|GT = "updated_at|gt";
  @SerializedName(SERIALIZED_NAME_UPDATED_AT|GT)
  private OffsetDateTime updatedAt|gt = null;

... which does not parse as Java.

openapi-generator version

020883fd

OpenAPI Declaration

paths:
  '/foo':
    get:
      parameters:
        - name: filter
          in: query
          required: false
          style: deepObject
          schema:
            properties:
              "updated_at|gt":
                type: string
                format: date-time

Command Line used for generation

java -jar openapi-generator-cli.jar generate -l java -i api.yml -o jclient

Steps to reproduce

Generate client.

Related issues/PRs

None.

Suggest a fix/enhancement

Escape parameter names properly such that the generator emits syntactically valid Java code.