pepper

Various Java utilities

Maven

Add pepper as dependency to your project through:

    <dependency>
         <groupId>io.github.solven-eu.pepper</groupId>
         <artifactId>pepper</artifactId>
         <version>${pepper.version}</version>
    </dependency>

pepper-java

Various utilities helping operating in Java on a daily basis.

Standard helpers

GCInspector is drop-in class providing standard logs related to GC activity

@Bean
	public IPepperThreadDumper pepperThreadDumper() {
		return new PepperThreadDump(ManagementFactory.getThreadMXBean());
	}

	@Bean
	public GCInspector gcInspector(IpepperThreadDumper pepperThreadDumper) {
		return new GCInspector(pepperThreadDumper);
	}

PepperLogHelper helps publishing relevant logs regarding memory and timings

Assert.assertEquals("0.09%", pepperLogHelper.getNicePercentage(123, 123456).toString());


Assert.assertEquals("9sec 600ms", pepperLogHelper.getNiceTime(9600).toString());
Assert.assertEquals("2min 11sec", pepperLogHelper.getNiceTime(131, TimeUnit.SECONDS).toString());


Assert.assertEquals("789B", pepperLogHelper.getNiceMemory(789L).toString());
Assert.assertEquals("607KB", pepperLogHelper.getNiceMemory(789L * 789).toString());
Assert.assertEquals("468MB", pepperLogHelper.getNiceMemory(789L * 789 * 789).toString());
Assert.assertEquals("360GB", pepperLogHelper.getNiceMemory(789L * 789 * 789 * 789).toString());
Assert.assertEquals("278TB", pepperLogHelper.getNiceMemory(789L * 789 * 789 * 789 * 789).toString());
Assert.assertEquals("214PB", pepperLogHelper.getNiceMemory(789L * 789 * 789 * 789 * 789 * 789).toString());

Fancy helpers

ObjectInputHandlingInputStream enables transmitting a raw InputStream through an ObjectInput

CartesianProductHelper helps computing covering cartesian products over sets defined by Collections and Maps.

PepperProcessHelper enables tracking the memory consumption of a process (would it be current JVM, a forked Process or any other process).

PepperProcessHelper.getProcessResidentMemory(processPID)

MapPath

This module inspires itself from xpath and jsonPath to manipulate standard java.util.Map.

See map-path

<dependency>
	<groupId>io.github.solven-eu.pepper</groupId>
	<artifactId>map-path</artifactId>
	<version>4.4</version>
</dependency>

Pepper-MAT

A fork from Eclipse MAT for HeapDump analysis. It improves original MAT by lowering the heap required to prepare MAT index files, while keeping the produced indexes compatible with the original MAT.

Original work: https://git.eclipse.org/c/mat/org.eclipse.mat.git

Additional way to fetch a HeapDump: https://schwartzdaniel.com/how-to-take-a-java-heapdump-without-downtime/ The point of this way is GDB produce a dump much faster than the JVM. Then, a new JVM can be started and the original JVM can be reloaded in a different machine. https://www.gnu.org/software/gdb/

• gdb –pid=$PID
• (gdb) gcore /tmp/jvm.core
• (gdb) detach
• (gdb) quit
• jmap -dump:format=b,file=jvm.hprof /usr/bin/java /tmp/jvm.core

Upgrade from 2.X to 3.X

Change groupId from <groupId>com.github.cormoran-io.pepper</groupId> to <groupId>io.github.solven-eu.pepper</groupId> Change imported package from import cormoran.pepper.X to import eu.solven.pepper.X

Release process

Tag and Publish

Do not -DskipTests, else it will skip javadoc which is mandatory for sonatype Do not -T 8 else the prompt for GPG may be lost in the logs

    mvn release:clean release:prepare release:perform -DskipStyle -Darguments="-Dmaven.test.skip -DskipStyle -Dmaven.javadoc.skip=false"
    git push --tags

In case of error:

    mvn reset --hard HEAD~~
    git tag -d pepper-XXX
    git push --delete origin