Previously, the Launcher was creating a new runner thread that would
call the application's main method. An exception thrown by this thread
is handled differently to one thrown by the JVM's main thread leading
to different exit behaviour. Furthermore, the separate thread isn't
actually necessary.
This commit removew the use of a separate runner thread from the
Launcher. This means that the JVM's exit behaviour will be consistent
and also removes the overhead of createing a starting an extra thread.
Closes gh-5006
Ensure that JarFile caches are cleared once the ApplicationContext has
loaded. Caches are cleared manually with the assumption that no
further class loading is likely.
Closes gh-4882
Refactor `spring-boot-loader` to reduce the amount of memory required
to load fat & exploded jars. Jar files now no longer store a full list
of entry data records, but instead use an array of entry name hashes.
Since ClassLoaders often ask each JAR if they contain a particular
entry (and mostly they do not), the hash array provides a quick way to
deal with misses. Only when a hash does exist is data actually loaded
from the underlying file.
In addition to the JarFile changes, the Archive abstraction has also
been updated to reduce memory consumption.
See gh-4882
Remove the use of JDK loggers in Launcher and PropertiesLauncher to
ensure allow the custom Log4j2 `LogManager` to be used with Spring Boot
applications.
Fixes gh-3815
Previously, if an application’s main method threw an exception,
MainMethodRunner would catch the exception and call System.exit(1).
This meant that the JVM would exit, irrespective of whether or not
any non-daemon threads were running. In contrast, when an application’s
main method was invoked directly (in an IDE, for example) the JVM
would not exit if one or more non-daemon threads were running. This
is standard JVM behaviour that we should be consistent with in the
launcher.
This commit updates MainMethodRunner to wrap any exception thrown by an
application’s main method in a RuntimeException and rethrow it. This
alllows the JVM to handle the exception and use its normal rules for
deciding whether or not it should exit.
Closes gh-4984
PropertiesLauncher creates a ClassLoader that is used by the Launcher
to load an application’s classes. During the creation of this
ClassLoader URLs from its ClassLoader. This resulted resulting in Java
agents that are added to the system class loader via the -javaagent
launch option being available on both the system class loader and the
created class loader. Java agents are intended to always be loaded by
the system class loader. Making them available on another class loader
breaks this model.
This is the same problem that was in ExecutableArchiveLauncher and
that was fixed in ee08667e (see gh-863).
This commit updates PropertiesLauncher so that it skips the URLs of
any Java agents (found by examining the JVM’s input arguments) when
copying URLs over to the new ClassLoader, thereby ensuring that Java
agents are only ever loaded by the system class loader.
Closes gh-4911
This commit completes the changes to consistently used static final
fields for Log instances that were started in ec2f33f9. Specifically it:
- Removes this. when accessing logger fields that are now static
- Renames some fields from log to logger
- Makes some logger fields static
See gh-4784
Update exit code support to allow the ExitCodeGenerator interface to
be placed on an Exception. Any uncaught exception implementing the
interface and returning a non `0` status will now trigger a System.exit
with the code.
Fixes gh-4803
Some libraries like aspectj are using findResource to see the raw
bytecode of a class. It will even call findResource for every method of
every class of beans that are post processed. This can be significant
performance hit on startup when LaunchedURLClassLoader and there are a
lot of nested jars.
See gh-3640
Fixes gh-4557
Some libraries like aspectj are using findResource to see the raw
bytecode of a class. It will even call findResource for every method of
every class of beans that are post processed. This can be significant
performance hit on startup when LaunchedURLClassLoader and there are a
lot of nested jars.
See gh-3640
Fixes gh-4557
Previously, JarFileArchive would always unpack any entries marked for
unpacking to ${java.io.tmpdir}/spring-boot-libs. This could cause
problems if multiple Spring Boot applications were running on the same
host:
- If the apps are run as different users the first application would
create the spring-boot-libs directory and the second and subsequent
applications may not have write permissions to that directory
- Multiple apps may overwrite each others unpacked libs. At best this
will mean one copy of a jar is overwritten with another identical
copy. At worst the jars may have different contents so that some of
the contents of the original jar disappear unexpectedly.
This commit updates JarFileArchive to use an application-specific
location when unpacking libs. A directory beneath ${java.io.tmpdir} is
still used but it's now named <jar-file-name>-spring-boot-libs-<uuid>.
A loop, limited to 1000 attempts, is used to avoid problems caused by
the uuid clashing.
Closes gh-4124
When nested jars are being used, hasMoreElements requires opening a
connection for an entry in every nested jar. If that entry doesn't
exist, a FileNotFoundException is thrown to indicate that a particular
jar doesn't contain the requested entry. This exception is used to
indicate the lack of an entry and is then swallowed, i.e. its stack
trace is of no importance. This means that the performance of
hasMoreElements can be improved by switching on fast exceptions while
it's being called. When fast exceptions are switched on a general
purpose pre-initialized FileNotFoundException is thrown rather than
creating a new FileNotFoundException instance each time.
In certain situations, the use of fast exceptions as described above
can improve performance fairly significantly. The JRE's default SAAJ
implementation uses META-INF/services-based discovery for _every_
request that's handled by Spring Web Services. Each discovery attempt
results in hasMoreElements being called making its performance
critical to throughput.
See gh-3640
