String deduplication Example in Java

README.md

jbang run --java-options="-XX:-UseStringDeduplication" https://gist.github.com/misTrasteos/225ca2f29996a20f88c8ddf0be3cd3b2#file-stringdeduplicationexample-java

Same number of String and char[] objects

jbang run --java-options="-XX:+UseStringDeduplication" https://gist.github.com/misTrasteos/225ca2f29996a20f88c8ddf0be3cd3b2#file-stringdeduplicationexample-java

char[] objects are being reused

Using String deduplication you can allocate much more String objects.

StringDeduplicationExample.java

///usr/bin/env jbang "$0" "$@" ; exit $?

//JAVA_OPTIONS -Xms128m -Xmx128m
//JAVA_OPTIONS -XX:+UseG1GC
//JAVA_OPTIONS -XX:+AlwaysTenure
//JAVA_OPTIONS -XX:StringDeduplicationAgeThreshold=1
//JAVA_OPTIONS -XX:+HeapDumpOnOutOfMemoryError

//DEPS org.apache.commons:commons-lang3:3.12.0

import org.apache.commons.lang3.RandomStringUtils;

import java.util.List;
import java.util.LinkedList;

public class StringDeduplicationExample {

    public static void main(String... args) {
        List<String> strings = new LinkedList<String>();
        
        while( args.length >= 0 )
            strings.add( RandomStringUtils.randomNumeric(2) );

        System.out.println( strings.size() );

    }

}