When we copied IOUtils into the Elasticsearch codebase from Lucene, we
brought with it its handling of throwables which are out of whack with
how we handle throwables in our codebase. This commit modifies our copy
of IOUtils to be consistent with how we handle throwables today: do not
catch them. We take advantage of this cleanup to simplify IOUtils.
Eclipse Oxygen doesn't seem to be able to infer the correct type
arguments for Arrays::asList in the given test context. Adding cast to
make this more explicit.
As we have factored Elasticsearch into smaller libraries, we have ended
up in a situation that some of the dependencies of Elasticsearch are not
available to code that depends on these smaller libraries but not server
Elasticsearch. This is a good thing, this was one of the goals of
separating Elasticsearch into smaller libraries, to shed some of the
dependencies from other components of the system. However, this now
means that simple utility methods from Lucene that we rely on are no
longer available everywhere. This commit copies IOUtils (with some small
formatting changes for our codebase) into the fold so that other
components of the system can rely on these methods where they no longer
depend on Lucene.
* Remove log4j dependency from elasticsearch-core
This removes the log4j dependency from our elasticsearch-core project. It was
originally necessary only for our jar classpath checking. It is now replaced by
a `Consumer<String>` so that the es-core dependency doesn't have external
dependencies.
The parts of #28191 which were moved in conjunction (like `ESLoggerFactory` and
`Loggers`) have been moved back where appropriate, since they are not required
in the core jar.
This is tangentially related to #28504
* Add javadocs for `output` parameter
* Change @code to @link
This is related to #27933. It introduces a jar named elasticsearch-core
in the lib directory. This commit moves the JarHell class from server to
elasticsearch-core. Additionally, PathUtils and some of Loggers are
moved as JarHell depends on them.