Add ADR-0004

docs/adr/0000-use-markdown-architectural-decision-records.md

@@ -7,19 +7,20 @@ Which format and structure should these records follow?
 
 ## Considered Options
 
-* [MADR](https://adr.github.io/madr/) 2.0.3 - The Markdown Architectural Decision Records
-* [Michael Nygard's template](http:https://thinkrelevance.com/blog/2011/11/15/documenting-architecture-decisions) - The first incarnation of the term "ADR"
-* [Sustainable Architectural Decisions](https://www.infoq.com/articles/sustainable-architectural-design-decisions) - The Y-Statements
+* [MADR](https://adr.github.io/madr/) 2.1.2 – The Markdown Architectural Decision Records
+* [Michael Nygard's template](http:https://thinkrelevance.com/blog/2011/11/15/documenting-architecture-decisions) – The first incarnation of the term "ADR"
+* [Sustainable Architectural Decisions](https://www.infoq.com/articles/sustainable-architectural-design-decisions) – The Y-Statements
 * Other templates listed at <https://github.com/joelparkerhenderson/architecture_decision_record>
-* Formless - No conventions for file format and structure
+* Formless – No conventions for file format and structure
 
 ## Decision Outcome
 
-Chosen option: "MADR 2.0.3", because
+Chosen option: "MADR 2.1.2", because
+
 * Implicit assumptions should be made explicit.
  Design documentation is important to enable people understanding the decisions later on.
  See also [A rational design process: How and why to fake it](https://doi.org/10.1109/TSE.1986.6312940).
 * The MADR format is lean and fits our development style.
 * The MADR structure is comprehensible and facilitates usage & maintenance.
 * The MADR project is vivid.
-* Version 2.0.3 is the latest one available when starting to document ADRs.
+* Version 2.1.2 is the latest one available when starting to document ADRs.

docs/adr/0004-use-mariadb-connector.md

@@ -0,0 +1,34 @@
+# Use MariaDB Connector
+
+## Context and Problem Statement
+
+JabRef needs to connect to a MySQL database.
+See [Shared SQL Database](https://help.jabref.org/en/SQLDatabase) for more information.
+
+## Considered Options
+
+* Use MariaDB Connector
+* Use MySQL Connector
+
+Other alternatives are listed at <https://stackoverflow.com/a/31312280/873282>.
+
+## Decision Outcome
+
+Chosen option: "Use MariaDB Connector", because comes out best (see below).
+
+## Pros and Cons of the Options
+
+### Use MariaDB Connector
+
+The [MariaDB Connector](https://mariadb.com/kb/en/library/about-mariadb-connector-j/) is a LGPL-licensed JDBC driver to connect to MySQL and MariaDB.
+
+* Good, because can be used as drop-in replacement for MySQL connectopr
+
+### Use MySQL Connector
+
+The [MySQL Connector](https://www.mysql.com/de/products/connector/) is distributed by Oracle and licensed under GPL-2. Source: <https://downloads.mysql.com/docs/licenses/connector-j-8.0-gpl-en.pdf>.
+Oracle added the [Universal FOSS Exception, Version 1.0](https://oss.oracle.com/licenses/universal-foss-exception/) to it, which seems to limit the effects of GPL.
+More information on the FOSS Exception are available at <https://www.mysql.com/de/about/legal/licensing/foss-exception/>.
+
+* Good, because it stems from the same development team than MySQL
+* Bad, because the "Universal FOSS Exception" makes licensing more complicated.

docs/adr/index.md

@@ -8,6 +8,7 @@ This log lists the architectural decisions for JabRef.
 - [ADR-0001](0001-use-crowdin-for-translations.md) - Use Crowdin for translations
 - [ADR-0002](0002-use-slf4j-for-logging.md) - Use slf4j together with log4j2 for logging
 - [ADR-0003](0003-use-gradle-as-build-tool.md) - Use Gradle as build tool
+- [ADR-0004](0004-use-mariadb-connector.md) - Use MariaDB Connector
 
 <!-- adrlogstop -->
 

docs/adr/template.md

@@ -1,6 +1,6 @@
 # [short title of solved problem and solution]
 
-* Status: [accepted | superseeded by [ADR-0005](0005-example.md) | deprecated | …] <!-- optional -->
+* Status: [proposed | rejected | accepted | deprecated | … | superseded by [ADR-0005](0005-example.md)] <!-- optional -->
 * Deciders: [list everyone involved in the decision] <!-- optional -->
 * Date: [YYYY-MM-DD when the decision was last updated] <!-- optional -->
 
@@ -27,11 +27,13 @@ Technical Story: [description | ticket/issue URL] <!-- optional -->
 
 Chosen option: "[option 1]", because [justification. e.g., only option, which meets k.o. criterion decision driver | which resolves force force | … | comes out best (see below)].
 
-Positive Consequences: <!-- optional -->
+### Positive Consequences <!-- optional -->
+
 * [e.g., improvement of quality attribute satisfaction, follow-up decisions required, …]
 * …
 
-Negative consequences: <!-- optional -->
+### Negative Consequences <!-- optional -->
+
 * [e.g., compromising quality attribute, follow-up decisions required, …]
 * …
 

external-libraries.txt

@@ -110,11 +110,6 @@ Project: java-diff-utils
 URL: https://github.com/java-diff-utils/java-diff-utils
 License: Apache-1.1
 
-Id: mysql:mysql-connector-java
-Project: MySQL Connector/J
-URL: http:https://www.mysql.de/downloads/connector/j/
-License: GPL-2.0 and Oracle's FOSS License Exception (http:https://www.mysql.com/about/legal/licensing/foss-exception/) allowing GPLv3
-
 Id: net.java.dev.glazedlists:glazedlists_java15
 Project: Glazed Lists
 URL: http:https://www.glazedlists.com/
@@ -195,6 +190,11 @@ Project: jsoup
 URL: https://github.com/jhy/jsoup/
 License: MIT
 
+Id: org.mariadb.jdbc:mariadb-java-client
+Project: MariaDB Java Client
+URL: https://mariadb.com/kb/en/library/about-mariadb-connector-j/
+License: LGPL-2.1-or-later
+
 Id: org.openoffice:juh
 Project: OpenOffice.org
 URL: http:https://www.openoffice.org/api/SDK