examples

BRKGA-MP-IPR for Java — examples

Runnable TSP examples for the BRKGA-MP-IPR Java edition. They are meant to be read while following the user guide.

This is a standalone Maven project: it depends on the published io.github.codeurjc:brkga-mp-ipr-java artifact from Maven Central, which ships the precompiled native binaries. So you need no C++ compiler — just:

• JDK 22 or newer
• Maven 3.9+
• Linux x86-64 (the platform the bundled binaries target; for other platforms or custom builds, see Recompiling below)

Get the examples

Download brkga_mp_ipr_java_examples.zip from the latest GitHub release and unzip it, or clone the repository and use the examples/ directory.

Run

With the helper script (compiles, resolves the classpath, runs with native access on):

./run.sh brkga.single.MainMinimal 27000001 \
    data/config/single.conf 10 data/instances/burma14.dat

Or directly with Maven (prints a harmless native-access warning):

mvn -q compile exec:java \
    -Dexec.mainClass=brkga.single.MainMinimal \
    -Dexec.args="27000001 data/config/single.conf 10 data/instances/burma14.dat"

Available examples

Main class	Description
brkga.single.MainMinimal	single-objective, minimal loop
brkga.single.MainMaximumIterations	single-objective, fixed iterations
brkga.single.MainComplete	single-objective, full options (docopt-style)
brkga.multi.MainMinimal	two-objective, minimal loop
brkga.multi.MainComplete	two-objective, full options
brkga.multi3.MainMinimal	synthetic three-objective demo

MainComplete takes named options, e.g.:

./run.sh brkga.single.MainComplete \
    --config data/config/single.conf --seed 27000001 \
    --stop_rule G --stop_arg 100 --maxtime 30 \
    --instance data/instances/brazil58.dat --threads 4

Bundled instances: burma14.dat (14 nodes), brazil58.dat (58), rd400.dat (400). Larger instances are available in the upstream library repository.

Decoders: basic vs optimized

• brkga.tsp.single.TspDecoder — the simple, readable decoder used throughout the guide.
• brkga.tsp.single.TspDecoderOptimized — same results, tuned for the hot path (the techniques are explained in JAVA_GUIDE.md).

Recompiling the native library (other objective counts, mating modes, …)

The bundled binaries cover the common cases. To change the number of objectives, the parallel-mating mode, or the extra-blob capacity, build your own binaries with Docker (no local toolchain needed) and point the JVM at them with -Dbrkga.bridge.dir=.... See JAVA_GUIDE.md → Recompiling the native library.