4.0.0 com.ankurm java-core-examples 1.0 hashmap-concurrenthashmap hashmap-concurrenthashmap HashMap vs ConcurrentHashMap: JMH put/get throughput under concurrent load, the computeIfAbsent recursion trap (verified on both), and null-key/null-value handling. 1.37 org.openjdk.jmh jmh-core ${jmh.version} org.openjdk.jmh jmh-generator-annprocess ${jmh.version} org.junit.jupiter junit-jupiter 5.11.0 test benchmarks org.apache.maven.plugins maven-compiler-plugin 3.13.0 25 org.openjdk.jmh jmh-generator-annprocess ${jmh.version} org.apache.maven.plugins maven-surefire-plugin 3.2.5 org.apache.maven.plugins maven-shade-plugin 3.5.1 package shade org.openjdk.jmh.Main