Rethink locking support within deegree

[copierrj]

We are currently using H2 to implement local locking. Given that this is the only thing we use H2 for we should rethink this strategy. We should at least be able to drop the H2 dependency as this would resolve #1250.

The WFS should use the locking functionality provided by the database backing the FeatureStore and when a file based FeatureStore is in use we could consider refusing locking requests.

[tfr42]

The TMC has the notion to remove the dependency to H2 and document that users have to provide a compatible database him/herself. As an alternative the feature is kept and an upgrade of H2 is required. Contributions are highly appreciated.

[stephanr]

The following matches in the source tree may also be wrong imports

• https://github.com/deegree/deegree3/search?q=org.h2.util.IOUtils&type=code
• maybe one of these should be used instead
  • org.deegree.commons.utils....
  • org.apache.commons.io.IOUtils

Other places where h2 is used are:

• https://github.com/deegree/deegree3/blob/327e7876b43c3885747840d5edc83df2940bc36a/deegree-datastores/deegree-featurestores/deegree-featurestore-commons/src/main/java/org/deegree/feature/persistence/lock/LockDbProviderProvider.java
• https://github.com/deegree/deegree3/blob/327e7876b43c3885747840d5edc83df2940bc36a/deegree-datastores/deegree-featurestores/deegree-featurestore-shape/src/main/java/org/deegree/feature/persistence/shape/DbfIndexImporter.java
• https://github.com/deegree/deegree3/blob/327e7876b43c3885747840d5edc83df2940bc36a/deegree-tests/deegree-resource-deps-tests/src/test/resources/workspace/jdbc/simplesqlh2.xml
• https://github.com/deegree/deegree3/blob/327e7876b43c3885747840d5edc83df2940bc36a/deegree-datastores/deegree-featurestores/deegree-featurestore-shape/src/main/java/org/deegree/feature/persistence/shape/H2WhereBuilder.java
• https://github.com/deegree/deegree3/blob/327e7876b43c3885747840d5edc83df2940bc36a/deegree-datastores/deegree-featurestores/deegree-featurestore-shape/src/main/java/org/deegree/feature/persistence/shape/DBFIndex.java
• Dependency on these modules
  • deegree-core-coverage
  • deegree-compliance-tests
  • root pom

[stephanr]

There is also a collision on Tables named "LOCKS", so if that was the only problem, #1296 would fix it, and we could at least upgrade H2 to a safer version.