Rafael Winterhalter raphw

software consultant who likes static types

raphw / MavenPomResolver.java

Last active December 8, 2024 12:29

Maven POM resolution (standalone)

	package codes.rafael.mavenpom;

	import org.w3c.dom.Document;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;
	import org.xml.sax.SAXException;

	import javax.xml.parsers.DocumentBuilderFactory;
	import javax.xml.parsers.ParserConfigurationException;
	import java.io.IOException;

raphw / ChecksumDiff.java

Created November 27, 2023 18:27

Computes checksums from a file

	import java.io.BufferedReader;
	import java.io.IOException;
	import java.io.UncheckedIOException;
	import java.nio.channels.FileChannel;
	import java.nio.charset.StandardCharsets;
	import java.nio.file.DirectoryStream;
	import java.nio.file.Files;
	import java.nio.file.Path;
	import java.nio.file.Paths;
	import java.security.MessageDigest;

raphw / TaskGraph.java

Created November 24, 2023 13:34

TaskGraph for build tool

	import java.util.*;
	import java.util.concurrent.CompletableFuture;
	import java.util.concurrent.CompletionStage;
	import java.util.concurrent.Executor;
	import java.util.function.BiFunction;
	import java.util.function.Function;

	public class TaskGraph<IDENTITY, INPUT, OUTPUT> implements Function<OUTPUT, CompletionStage<OUTPUT>> {

	private final Executor executor;

raphw / Build.java

Created November 23, 2023 21:53

Mock-up for Java-based build tool (single source execution)

	import javax.tools.*;
	import java.io.IOException;
	import java.io.InputStream;
	import java.nio.charset.StandardCharsets;
	import java.nio.file.DirectoryStream;
	import java.nio.file.Files;
	import java.nio.file.Path;
	import java.nio.file.Paths;
	import java.util.ArrayList;
	import java.util.List;

raphw / sample.jsh

Created November 22, 2023 12:28

	System.out.println(1 + 2);
	/exit

raphw / timestamps.txt

Last active November 9, 2022 20:59

Timestamps handled by Oracle/Postgres.

	What is the general difference when handling timestamps?
	Postgres: Does not store time zone, only displays column time zone aware.
	Oracle: Stores time zone as part of type.

	What does CURRENT_TIMESTAMP return?
	Postgres: TIMESTAMP WITH TIMEZONE displaying in session time zone.
	Oracle: TIMESTAMP WITH TIMEZONE in session time zone.

	What happens when converting a TIMESTAMP (without time zone) with "AT TIME ZONE '<name>'"?
	Postgres: Assumes TIMESTAMP to be in zone <name>.

raphw / TimestampTest.java

Created November 8, 2022 08:36

Timestamps with JDBC

	import java.sql.Connection;
	import java.sql.PreparedStatement;
	import java.sql.ResultSet;
	import java.sql.SQLException;
	import java.sql.Statement;
	import java.sql.Timestamp;
	import java.time.LocalDateTime;
	import java.time.ZoneOffset;
	import java.time.ZonedDateTime;
	import java.util.Calendar;

raphw / UnwrappingClassVisitor.java

Created August 17, 2022 20:10

	package net.bytebuddy.build.gradle;

	import net.bytebuddy.utility.OpenedClassReader;
	import net.bytebuddy.utility.nullability.MaybeNull;
	import org.objectweb.asm.*;

	import java.util.HashMap;
	import java.util.Map;

	public class UnwrappingClassVisitor extends ClassVisitor {

raphw / OracleNotificationTest.java

Created August 12, 2022 20:45

Oracle change notification issue

	import oracle.jdbc.OracleConnection;
	import oracle.jdbc.OracleStatement;
	import oracle.jdbc.dcn.DatabaseChangeEvent;
	import oracle.jdbc.dcn.DatabaseChangeListener;
	import oracle.jdbc.dcn.DatabaseChangeRegistration;
	import oracle.jdbc.pool.OracleDataSource;
	import org.junit.Rule;
	import org.junit.Test;
	import org.testcontainers.Testcontainers;
	import org.testcontainers.containers.JdbcDatabaseContainer;

raphw / run.sh

Last active February 18, 2024 08:48

Runs Mockito on Graal VM

	#!/bin/bash
	set -x
	set -e
	if [[ -z $1 ]]; then
	echo "Specify location of Graal VM as first argument"
	exit 1
	fi
	$1/bin/gu install native-image
	rm -rf META-INF sample sample.build_artifacts.txt Sample.* *.jar
	echo "public class Sample {