javap6大纲Java hashmap 的相关内容

【JavaP6大纲】Java基础篇：HashMap底层原理

HashMap底层原理？HashMap是Map的一个实现类，它是以键值对存储数据的，Key-Value都是Map Entry中的属性。当我们向HashMap中存放一个元素(k1,v1)，先根据k1的hashCode方法来决定在数组中存放的位置。如果这个位置没有其它元素，将(k1,v1)直接放入一个N...

【JavaP6大纲】Java基础篇：HashMap扩容机制

HashMap扩容机制将(K1V1)直接放入 Node类型的数组中，这个数组初始化容量是16，默认的加载因子是0.75，也就是当元素加到12的时候，底层会进行扩容，扩容为原来的2倍可能引发的问题：HashMap实际使用过程中会出现一些线程安全问题，在JDK1.7中，当并发执行扩容操...

「大师课」搞定 Java 开发基础

23 课时 |

8714 人已学 |

加入学习

Java Spring Boot 2.6.0开发实战-1024程序员节创造营公益课

5 课时 |

1162 人已学 |

加入学习

Java Web开发-Web应用、Tomcat、HTTP请求与响应

17 课时 |

1440 人已学 |

加入学习

【JavaP6大纲】Java基础篇：HashMap加载因子为什么是0.75？

HashMap加载因子为什么是0.75如果加载因子比较大，扩容发生的频率比较低，浪费的空间比较小，发生hasha冲突的几率比较大比如，加载因子是1的时候，hashmap长度为128，实际存储元素的数最在64至128之间时间段比较多，这个时间段发生hash冲突比较多，造成数组中其中一条链...

共有3条

< 1 >

跳转至： GO

更新时间 2023-06-15 17:28:08

本页面内关键词为智能算法引擎基于机器学习所生成，如有任何问题，可在页面下方点击"联系我们"与我们沟通。

产品推荐

{"optioninfo":{"dynamic":"ture","static":"true"},"simplifiedDisplay":"newEdition","newCard":[{"ifIcon":"img","link":"https://img.alicdn.com/tfs/TB1XY8hGYr1gK0jSZFDXXb9yVXa-1740-328.png","icon":"","iconImg":"https://img.alicdn.com/tfs/TB1iJox2Br0gK0jSZFnXXbRRXXa-200-200.png","contentLink":"https://www.aliyun.com/product/arms","title":"应用实时监控服务 ARMS","des":"应用实时监控服务ARMS 包含前端监控，应用监控、云拨测等模块，覆盖小程序、APP、网站等客户端及ECS、Serverless、容器等环境，为分布式、微服务应用提供端到端性能监控与全链路追踪诊断， 让运维监控更加高效便捷。","link1":"https://common-buy.aliyun.com/?spm=5176.26849858.J_5253785160.3.3887564cBbVoUd&commodityCode=arms_serverless_public_cn","btn1":"立即开通（每月50GB额度）","link2":"https://common-buy.aliyun.com/?spm=5176.8140086.1280672.buy11.30f2bb91uujI1A&commodityCode=arms_app_bag#/buy","btn2":"资源包购买（旧版计费）","btn3":"帮助文档","link3":"https://help.aliyun.com/zh/arms/application-monitoring/getting-started/overview?spm=a2c4g.11186623.0.0.502edf6bVmoHkw","infoGroup":[{"infoName":"最佳实践","infoContent":{"firstContentLink":"https://www.aliyun.com/activity/middleware/ObservabilityConference2022?spm=5176.26849857.J_5253785160.2.1f4415e9ite0CU","firstContentName":"新老用户限时钜惠","lastContentLink":"https://www.aliyun.com/activity/middleware/observability","lastContentName":"最新实践 & 公开课"}},{"infoName":"相关推荐","infoContent":{"firstContentLink":"https://www.aliyun.com/activity/middleware/Application_monitoring?spm=5176.8140086.J_4084816840.3.1db8be45A6RecL","firstContentName":"应用监控-Java监控","lastContentName":"前端监控-Web应用监控","lastContentLink":"https://www.aliyun.com/activity/middleware/web_monitoring?spm=5176.26849857.J_9938243310.4.640115e9rV41KE"}},{"infoName":"产品入门","infoContent":{"firstContentName":"快速接入","lastContentName":"计费说明","firstContentLink":"https://help.aliyun.com/zh/arms/application-monitoring/getting-started/monitor-java-applications-1/?spm=a2c4g.11186623.0.0.36badf6bscAkU3","lastContentLink":"https://help.aliyun.com/zh/arms/application-monitoring/product-overview/billing-description?spm=a2c4g.11186623.0.0.41ba1a08NHoPA3"}},{"infoName":"相关推荐","infoContent":{"firstContentName":" 云拨测-网络测速","firstContentLink":"https://www.aliyun.com/activity/middleware/website/performance/test?spm=5176.20960838.0.0.6d33305emfVIyC","lastContentLink":"","lastContentName":""}}]}],"card":[],"search":[],"infoCard":[{"bannerUrl":"https://img.alicdn.com/tfs/TB1Xf81a3gP7K4jSZFqXXamhVXa-5169-974.jpg","bannerTitle":"mPaaS 小程序","bannerContent":"源自于支付宝小程序框架，亿级线上业务体量的锤炼，安全性媲美支付宝原生能力。<br>不仅面向自有 App 投放小程序，更可快速构建打包，覆盖支付宝、淘宝、钉钉等应用。","liveButtonName":"查看详情","liveButtonLink":"https://www.aliyun.com/product/mobilepaas/mpaas-miniprogram","contentTitle":"提供即开即用的端上体验","homePageLink":"https://common-buy.aliyun.com/?spm=5176.14673561.J_8751524360.2.56702709BussF3&commodityCode=mpaas_beta#/open","homePageName":"免费试用","linkGroup":[{"linkContent":"发布包大小极致优化，节省流量和存储。"},{"linkContent":"服务迭代不再受发版限制，快速发布，快速迭代。"},{"linkContent":"业务开发效率更加优秀，一次开发，多端运行。"}]}],"title":{"mainTitle":"应用实时监控服务ARMS","subtitle":"","linkUrl":"","btnText":"查看详情"},"visual":{"topbg":"https://img.alicdn.com/tfs/TB1bQuBIYH1gK0jSZFwXXc7aXXa-3840-740.gif","icon":"","textColor":"dark"},"dataList":[{"summary":"啦啦啦","author":"wuwu","linksUrl":"#"}],"sceneCard":[],"txt":[]}

{"$env":{"JSON":{}},"$page":{"env":"production"},"$context":{"optioninfo":{"dynamic":"ture","static":"true"},"simplifiedDisplay":"newEdition","newCard":[{"ifIcon":"img","link":"https://img.alicdn.com/tfs/TB1XY8hGYr1gK0jSZFDXXb9yVXa-1740-328.png","icon":"","iconImg":"https://img.alicdn.com/tfs/TB1iJox2Br0gK0jSZFnXXbRRXXa-200-200.png","contentLink":"https://www.aliyun.com/product/arms","title":"应用实时监控服务 ARMS","des":"应用实时监控服务ARMS 包含前端监控，应用监控、云拨测等模块，覆盖小程序、APP、网站等客户端及ECS、Serverless、容器等环境，为分布式、微服务应用提供端到端性能监控与全链路追踪诊断， 让运维监控更加高效便捷。","link1":"https://common-buy.aliyun.com/?spm=5176.26849858.J_5253785160.3.3887564cBbVoUd&commodityCode=arms_serverless_public_cn","btn1":"立即开通（每月50GB额度）","link2":"https://common-buy.aliyun.com/?spm=5176.8140086.1280672.buy11.30f2bb91uujI1A&commodityCode=arms_app_bag#/buy","btn2":"资源包购买（旧版计费）","btn3":"帮助文档","link3":"https://help.aliyun.com/zh/arms/application-monitoring/getting-started/overview?spm=a2c4g.11186623.0.0.502edf6bVmoHkw","infoGroup":[{"infoName":"最佳实践","infoContent":{"firstContentLink":"https://www.aliyun.com/activity/middleware/ObservabilityConference2022?spm=5176.26849857.J_5253785160.2.1f4415e9ite0CU","firstContentName":"新老用户限时钜惠","lastContentLink":"https://www.aliyun.com/activity/middleware/observability","lastContentName":"最新实践 & 公开课"}},{"infoName":"相关推荐","infoContent":{"firstContentLink":"https://www.aliyun.com/activity/middleware/Application_monitoring?spm=5176.8140086.J_4084816840.3.1db8be45A6RecL","firstContentName":"应用监控-Java监控","lastContentName":"前端监控-Web应用监控","lastContentLink":"https://www.aliyun.com/activity/middleware/web_monitoring?spm=5176.26849857.J_9938243310.4.640115e9rV41KE"}},{"infoName":"产品入门","infoContent":{"firstContentName":"快速接入","lastContentName":"计费说明","firstContentLink":"https://help.aliyun.com/zh/arms/application-monitoring/getting-started/monitor-java-applications-1/?spm=a2c4g.11186623.0.0.36badf6bscAkU3","lastContentLink":"https://help.aliyun.com/zh/arms/application-monitoring/product-overview/billing-description?spm=a2c4g.11186623.0.0.41ba1a08NHoPA3"}},{"infoName":"相关推荐","infoContent":{"firstContentName":" 云拨测-网络测速","firstContentLink":"https://www.aliyun.com/activity/middleware/website/performance/test?spm=5176.20960838.0.0.6d33305emfVIyC","lastContentLink":"","lastContentName":""}}]}],"card":[],"search":[],"infoCard":[{"bannerUrl":"https://img.alicdn.com/tfs/TB1Xf81a3gP7K4jSZFqXXamhVXa-5169-974.jpg","bannerTitle":"mPaaS 小程序","bannerContent":"源自于支付宝小程序框架，亿级线上业务体量的锤炼，安全性媲美支付宝原生能力。<br>不仅面向自有 App 投放小程序，更可快速构建打包，覆盖支付宝、淘宝、钉钉等应用。","liveButtonName":"查看详情","liveButtonLink":"https://www.aliyun.com/product/mobilepaas/mpaas-miniprogram","contentTitle":"提供即开即用的端上体验","homePageLink":"https://common-buy.aliyun.com/?spm=5176.14673561.J_8751524360.2.56702709BussF3&commodityCode=mpaas_beta#/open","homePageName":"免费试用","linkGroup":[{"linkContent":"发布包大小极致优化，节省流量和存储。"},{"linkContent":"服务迭代不再受发版限制，快速发布，快速迭代。"},{"linkContent":"业务开发效率更加优秀，一次开发，多端运行。"}]}],"title":{"mainTitle":"应用实时监控服务ARMS","subtitle":"","linkUrl":"","btnText":"查看详情"},"visual":{"topbg":"https://img.alicdn.com/tfs/TB1bQuBIYH1gK0jSZFwXXc7aXXa-3840-740.gif","icon":"","textColor":"dark"},"dataList":[{"summary":"啦啦啦","author":"wuwu","linksUrl":"#"}],"sceneCard":[],"txt":[]}}