[Java Jersey] Update ApiClient.mustache Jersey doesn't allow entities in method DELETE

[eric-rolli]

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[eric-rolli]

@bbdouglas @sreeshas @jfiala @lukoyanov @cbornet @jeff9finger @karismann @Zomzog @lwlee2608 @martin-mfg
Correction for Java Jersey2/3 generation.

[wing328]

@eric-rolli thanks for the PR

If I remember correctly, some users need send the payload in DELETE request: #13457

Given that your use cases do not require sending payload in DELETE request, what about leaving the code as it's?

[eric-rolli]

@wing328
The problem is that the jersey library enforces that the entity must be null.
See org.glassfish.jersey.client.JerseyInvocation
https://github.com/eclipse-ee4j/jersey/blob/2.x/core-client/src/main/java/org/glassfish/jersey/client/JerseyInvocation.java
https://github.com/eclipse-ee4j/jersey/blob/4.0/core-client/src/main/java/org/glassfish/jersey/client/JerseyInvocation.java

private static Map<String, EntityPresence> initializeMap() {
	HashMap<String, EntityPresence> map = new HashMap<String, EntityPresence>();
	map.put("DELETE", EntityPresence.MUST_BE_NULL);
	map.put("GET", EntityPresence.MUST_BE_NULL);
	map.put("HEAD", EntityPresence.MUST_BE_NULL);
	map.put("OPTIONS", EntityPresence.OPTIONAL);
	map.put("PATCH", EntityPresence.MUST_BE_PRESENT);
	map.put("POST", EntityPresence.OPTIONAL);
	map.put("PUT", EntityPresence.MUST_BE_PRESENT);
	map.put("TRACE", EntityPresence.MUST_BE_NULL);
	return map;
}

private void validateHttpMethodAndEntity(ClientRequest request) {
	String method;
	EntityPresence entityPresence;
	boolean suppressExceptions = PropertiesHelper.isProperty((Object) request.getConfiguration()
			.getProperty("jersey.config.client.suppressHttpComplianceValidation"));
	Object shcvProperty = request.getProperty("jersey.config.client.suppressHttpComplianceValidation");
	if (shcvProperty != null) {
		suppressExceptions = PropertiesHelper.isProperty((Object) shcvProperty);
	}
	if ((entityPresence = METHODS
			.get((method = request.getMethod()).toUpperCase(Locale.ROOT))) == EntityPresence.MUST_BE_NULL
			&& request.hasEntity()) {
		if (!suppressExceptions)
			throw new IllegalStateException(
					LocalizationMessages.ERROR_HTTP_METHOD_ENTITY_NOT_NULL((Object) method));
		LOGGER.warning(LocalizationMessages.ERROR_HTTP_METHOD_ENTITY_NOT_NULL((Object) method));
		return;
	} else {
		if (entityPresence != EntityPresence.MUST_BE_PRESENT || request.hasEntity())
			return;
		if (!suppressExceptions)
			throw new IllegalStateException(LocalizationMessages.ERROR_HTTP_METHOD_ENTITY_NULL((Object) method));
		LOGGER.warning(LocalizationMessages.ERROR_HTTP_METHOD_ENTITY_NULL((Object) method));
	}
}

But the current openapi generated code always produces a non-null Entity object, even if the body in null.
See method serialize in ApiClient.mustache
For a null Body the Entity object will contain an empty string instead of null!

The result is that DELETE methods are not usable with the code generated for the jersey library.

Would the following modification be OK?
} else if ("DELETE".equals(method)) {
if ("".equals(entity.getEntity())) {
response = invocationBuilder.method("DELETE");
} else {
response = invocationBuilder.method("DELETE", entity);
}

[wing328]

Would the following modification be OK?

I think we can give it a try

[eric-rolli]

@wing328
I made the changes to send the entity only if it is not empty

[wing328]

thanks. let's give it a try

please test it later after snapshot version published (or test it locally)