Is this you? As a journalist, you can create a free Muck Rack account to customize your profile, list your contact preferences, and upload a portfolio of your best work.
Claim your profile
Articles by import org.openjdk.jmh.annotations.Benchmark
Testing Java integer cache
In one of my posts, I made 2 + 2 equal to 5 using Java 21. In summary, the Integer class in Java has a cache for values from -128 to 127. I manipulated these values by swapping the number 4 with 5. This made me ponder the importance of this cache and its impact on a program. So, I decided to conduct a test using JMH, which is a micro benchmark API.
103.【Java Microbenchmark Harness】（一）
(一)、JMH概述 JMH（Java Microbenchmark Harness）是一个 Java 工具，用于构建、运行和分析用 Java 和其他针对 JVM 的语言编写的 纳米/微米/毫/宏观 基准测试，而且是由Java虚拟机团队开发的。简单说，就是用来测量代码运行性能，简称 :“Java性能检测工具”。 JMH官网： https://openjdk.org/projects/code-tools/jmh/ JMH源码下载： https://github.com/openjdk/jmh (1).没有JMH的时候我们怎么进行测试的? 我们利用结束的时间戳 - 结束后的时间戳 (2).利用JMH进行测试 添加依赖 (二)、JMH运用展示 源码 解释 (三)、JMH注解 @Warmip 预热 预热: 执行一次，一次1秒 真实测试执行一次，一次一秒 源码 源码 第一个测试 第二个测试 第三个测试 第四次测试 第五次测试 第六次测试
JMH - Java代码基准测试工具，代码性能问题验证测试
在日常开发工作当中，开发人员可能有这些困惑：自己写的这个方法性能到底怎么样？在原接口实现方法中添加了新的业务逻辑，对整个接口的性能影响有多少？有多种实现方式(或开源类库)，到底哪一种性能更好？ 当遇到类似困惑或者说问题的时候，怎么办呢？当然是测试验证，实践出真知！本文讲述的就是一个方法级别的性能测试工具—— JMH。 1、什么是JMH JMH，即 Java Microbenchmark Harness，是专门用于代码微基准测试的工具套件。何谓Micro Benchmark呢？简单的来说就是基于方法层面的基准测试，精度可以达到微秒级。其由 Oracle/openjdk 内部开发JIT编译器的大佬们所开发，作为java的方法级性能测试工具可以说是根正苗红了。（官方地址：http://hg.openjdk.java.net/code-tools/jmh/ ） 2、JMH适用的典型场景 a、优化热点方法，准确的知道某个方法的执行耗时，以及不同入参与最终实际耗时的关系，从而针对性的进行优化； b、寻找最佳方案，验证接口方法不同实现方式的实际吞吐量，从而确定最佳实现方式...
Comparing Map.of() and New HashMap() in Java
Java is a popular programming language used for developing a wide range of applications, including web, mobile, and desktop applications. It provides many useful data structures for developers to use in their programs, one of which is the Map interface. The Map interface is used to store data in key-value pairs, making it an essential data structure for many applications.
Project Loom And Kotlin: Some Experiments
The publishing of Java 19 in September 2022 heralded the first public release of the much-awaited Project Loom into the JVM (Java Virtual Machine) ecosystem. A brief description for those who are unaware: Project Loom is an endeavor year in the making by the developers of the Java programming language to enable the use of virtual threads within Java code.
Finding When Premature Optimization Is Evil
This article is based on the Software Mistakes and Tradeoffs book by Tomasz Lelek and Jon Skeet. There is an old computer science saying that Premature Optimization is the root of all evil. The saying has stuck around because it’s accurate for a lot of use cases. Without any input data about expected traffic and SLA, it’s hard to reason about your code and its required performance. Optimizing random paths in code in such a situation is like shooting in the dark.
Show More
loading
Actions
Is this you?
As a journalist, you can create a free Muck Rack account to customize your profile, list your contact preferences, and upload a portfolio of your best work.Get in touch with import
Contact import, search articles and posts on X, monitor coverage, and track replies from one place.
Learn more about Muck Rack