Replace wiki link with relative repository link.

The endpoint currently returns the number of contents of the room and a
list of all content groups with their number of contents. Additional
stats like total answer and comment are not set yet and have to be added
later.

Refs #45.

Beans related to authentication providers are now only initialized if
they have been enabled via configuration.

Besides eliminating memory usage and initialization time of the beans
this fixes issues caused by filters of disabled authentication
providers.

Fixes #35, #50.

The deletion of users now triggers a cascading deletion for rooms owned
by the user.

* Update CouchDB section for version 2
* Remove "or newer" for OpenJDK
  (ARSnova 2 does not run on JDK 11)
* Adjustments for Debian 9/10
* Install Tomcat 9

An PropertySourcesPlaceholderConfigurer bean was still set up which
tried to load the legacy properties files.

Refs !137.

* Fix delayed answer creation
* Fix deletion of all contents of a group
* Fix deletion of all answers of a content
* Fix answer count for groups
* Initialize new answers with round 1

Use updated content group handling and remove all references to the
old `variant` property of contents/answers.

The following /v2 endpoints are now fully implemented:
* Deleting all contents of a group (/)
* Retrieving ids of unanswered content in a group (/unanswered)
* Deleting all answers of contents in a group (/answers)
* Counting answers of a group (/answercount)

The `ContentFindQueryService` now supports filtering contents of a room
that are not part of any content group.

Content groups are now a separate entity with their own repository and
service and endpoint. A content group can no longer be set when creating
a new content. Instead the new API endpoint has to be used to add the
content to a group.

Account activation is now using the ban logic as used for login failure
logic.

The account activation and reset mail now only contain the code. String
placeholders are numbered correctly again. The activation and reset
keys' length has been reduced to 8 characters.

Fixes #47.

Removed unused legacy forwards.

Daniel Gerhardt authored 5 years ago and Daniel Gerhardt committed 5 years ago

The JWT is now read from the Authorization header:
	Authorization: Bearer <JWT>
The Arsnova-Auth-Token header is no longer supported.

Using a standard header simplifies integration of the API with other
services and HTTP/REST libraries and tools.

RFC 6750:
https://tools.ietf.org/html/rfc6750

Daniel Gerhardt authored 5 years ago and Daniel Gerhardt committed 5 years ago

We do not use any data sources at the moment and the auto config causes
problems when the application is deployed to Tomcat.

Daniel Gerhardt authored 5 years ago and Daniel Gerhardt committed 5 years ago

Methods annotated with @Timed now use Micrometers annotation. The @Gauge
annotation has been remove without replacement for now.

While configuration for the use of Micrometer's TimedAspect has been
prepared, it is not yet active because of compatibility issues with
compile-time weaving.
See https://github.com/micrometer-metrics/micrometer/issues/1149.

Daniel Gerhardt authored 5 years ago and Daniel Gerhardt committed 5 years ago

The new endpoint provide metrics including information about application
health, environment, configuration, beans, caches and performance via
Spring Actuator. Additional custom endpoints for version info and
statistics are available.

Content type `application/json` may not be set for the `Accept` header
of requests to the management API. Otherwise, only a JSON stub is
returned. `application/vnd.spring-boot.actuator.v2+json` or `*/*` should
be used instead.

To allow monitoring of metrics, a Prometheus endpoint is provided via
Micrometer.

Web API documentation:
https://docs.spring.io/spring-boot/docs/2.1.x/actuator-api/html/

Daniel Gerhardt authored 5 years ago and Tom Käsler committed 5 years ago

The Nashorn ScriptEngine is deprecated since JDK 11 as described by
JEP 335. We now include GraalJS as a replacement.

Related docs:
* https://github.com/graalvm/graaljs.
* https://openjdk.java.net/jeps/174.
* https://openjdk.java.net/jeps/335.

Validation is performed before entities are persisted using Hibernate
Validator, the reference implementation for Bean Validation 2.0
(JSR 380).

Refs #23.

The location of `application.yml` can now be set via environment
variable `ARSNOVA_CONFIG_DIR` or Java system property
`arsnova.config-dir`.

For most of the configuration property classes are now used instead of
using property injection via @Value.

* Removed obsolete commented-out code.
* Fixed indentation of commented out code.
* Added FIXME comments where old code still has to be migrated.

Rules:
* (naming) ParameterName
* (naming) LocalVariableName
* (naming) MemberName
* (naming) InterfaceTypeParameterName
* (naming) AbbreviationAsWordInName
* (modifier) ModifierOrder
* (blocks) NeedBraces
* (coding) OneStatementPerLine
* (coding) MultipleVariableDeclarations
* (coding) VariableDeclarationUsageDistance
* (coding) MissingSwitchDefault
* (coding) OverloadMethodsDeclarationOrder
* (extension) RightCurlySame
* (misc) ArrayTypeStyle

The following conventions have been applied:
* Rule: (sizes) LineLength