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<rss xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:media="http://search.yahoo.com/mrss/" version="2.0"><channel><title>分类：JAVA - MedeMede</title><link>https://x.medemede.cn/categories/java</link><atom:link href="https://x.medemede.cn/categories/java/feed/categories/java.xml" rel="self" type="application/rss+xml"/><description>MedeMede</description><generator>Halo v2.24.2</generator><language>zh-cn</language><image><url>https://i.loli.net/2020/11/12/o6rsqgEJ78KtdhI.jpg</url><title>分类：JAVA - MedeMede</title><link>https://x.medemede.cn/categories/java</link></image><lastBuildDate>Wed, 20 May 2026 21:31:44 GMT</lastBuildDate><item><title><![CDATA[二分查找的边界问题]]></title><link>https://x.medemede.cn/archives/%E4%BA%8C%E5%88%86%E6%9F%A5%E6%89%BE%E7%9A%84%E8%BE%B9%E7%95%8C%E9%97%AE%E9%A2%98</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=%E4%BA%8C%E5%88%86%E6%9F%A5%E6%89%BE%E7%9A%84%E8%BE%B9%E7%95%8C%E9%97%AE%E9%A2%98&amp;url=/archives/%E4%BA%8C%E5%88%86%E6%9F%A5%E6%89%BE%E7%9A%84%E8%BE%B9%E7%95%8C%E9%97%AE%E9%A2%98" width="1" height="1" alt="" style="opacity:0;">使用二分查找时，特别是涉及左右边界时，不同的写法会产生不同的效果， right 是闭区间还是开区间 以及 left&amp;lt;right 还是 left&amp;lt;=right 会影响最终的返回结果。public class BinarySearch { /** * 查找左边界： *]]></description><guid isPermaLink="false">/archives/%E4%BA%8C%E5%88%86%E6%9F%A5%E6%89%BE%E7%9A%84%E8%BE%B9%E7%95%8C%E9%97%AE%E9%A2%98</guid><dc:creator>Saber</dc:creator><category>JAVA</category><pubDate>Mon, 26 Jul 2021 09:50:13 GMT</pubDate></item><item><title><![CDATA[解决IDEA问题 Cause: zip END header not found]]></title><link>https://x.medemede.cn/archives/i-d-e-a-de-g-r-a-d-l-e-mo-ren-xia-zai-wei-zhi--jie-jue-c-a-u-s-e---z-i-p--e-n-d--h-e-a-d-e-r--n-o-t--f-o-u-n-d</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=%E8%A7%A3%E5%86%B3IDEA%E9%97%AE%E9%A2%98%20Cause%3A%20zip%20END%20header%20not%20found&amp;url=/archives/i-d-e-a-de-g-r-a-d-l-e-mo-ren-xia-zai-wei-zhi--jie-jue-c-a-u-s-e---z-i-p--e-n-d--h-e-a-d-e-r--n-o-t--f-o-u-n-d" width="1" height="1" alt="" style="opacity:0;">IDEA在编译Gradle项目时会自动下载对应版本的Gradle-XXX.zip，因为某些原因经常会下载失败，进而造成错误：Cause: zip END header not found.解决办法也很简单，就是把损坏的压缩包删除，尝试重写编译。默认的下载位置在 用户目录/.gradle/wrappe]]></description><guid isPermaLink="false">/archives/i-d-e-a-de-g-r-a-d-l-e-mo-ren-xia-zai-wei-zhi--jie-jue-c-a-u-s-e---z-i-p--e-n-d--h-e-a-d-e-r--n-o-t--f-o-u-n-d</guid><dc:creator>Saber</dc:creator><category>JAVA</category><pubDate>Fri, 16 Apr 2021 13:35:31 GMT</pubDate></item><item><title><![CDATA[osv流程简解]]></title><link>https://x.medemede.cn/archives/osv%E6%B5%81%E7%A8%8B%E7%AE%80%E8%A7%A3</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=osv%E6%B5%81%E7%A8%8B%E7%AE%80%E8%A7%A3&amp;url=/archives/osv%E6%B5%81%E7%A8%8B%E7%AE%80%E8%A7%A3" width="1" height="1" alt="" style="opacity:0;">]]></description><guid isPermaLink="false">/archives/osv%E6%B5%81%E7%A8%8B%E7%AE%80%E8%A7%A3</guid><dc:creator>Saber</dc:creator><enclosure url="https://x.medemede.cn/apis/api.storage.halo.run/v1alpha1/thumbnails/-/via-uri?uri=https%3A%2F%2Fi.loli.net%2F2020%2F11%2F12%2FJqW5HVukaXxNCAT.png&amp;size=m" type="image/jpeg" length="13812"/><category>python</category><category>JAVA</category><pubDate>Sat, 23 Nov 2019 04:37:53 GMT</pubDate></item><item><title><![CDATA[HadoopHA之ResourceManager HA]]></title><link>https://x.medemede.cn/archives/1550166403289</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=HadoopHA%E4%B9%8BResourceManager%20HA&amp;url=/archives/1550166403289" width="1" height="1" alt="" style="opacity:0;">配置Yarn在配置完成NameNodeHA的基础上，只需再配置一下yarn-site.xml即可。&amp;]]></description><guid isPermaLink="false">/archives/1550166403289</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Thu, 14 Feb 2019 17:54:00 GMT</pubDate></item><item><title><![CDATA[HaoopHA之NameNode HA]]></title><link>https://x.medemede.cn/archives/1550159816422</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=HaoopHA%E4%B9%8BNameNode%20HA&amp;url=/archives/1550159816422" width="1" height="1" alt="" style="opacity:0;">先配置好Haoop集群配置ZookeeperHaoopHA的自动故障转移需要Zookeeper的支持]]></description><guid isPermaLink="false">/archives/1550159816422</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Linux</category><category>Hadoop</category><pubDate>Thu, 14 Feb 2019 16:15:00 GMT</pubDate></item><item><title><![CDATA[Java操作Zookeeper]]></title><link>https://x.medemede.cn/archives/1550154253961</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=Java%E6%93%8D%E4%BD%9CZookeeper&amp;url=/archives/1550154253961" width="1" height="1" alt="" style="opacity:0;">ZooKeeper的操作较为简单，下面是一个简单的客户端操作实例客户端监听服务器上下线的简单实现：G]]></description><guid isPermaLink="false">/archives/1550154253961</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Thu, 14 Feb 2019 14:32:00 GMT</pubDate></item><item><title><![CDATA[MapReduce大纲]]></title><link>https://x.medemede.cn/archives/1549712548265</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=MapReduce%E5%A4%A7%E7%BA%B2&amp;url=/archives/1549712548265" width="1" height="1" alt="" style="opacity:0;">1.Writable序列化序列化就是把内存中的对象，转换成字节序列（或其他数据传输协议）以便于存储（]]></description><guid isPermaLink="false">/archives/1549712548265</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Sat, 9 Feb 2019 12:24:00 GMT</pubDate></item><item><title><![CDATA[MapReduce编程规范]]></title><link>https://x.medemede.cn/archives/1549683494970</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=MapReduce%E7%BC%96%E7%A8%8B%E8%A7%84%E8%8C%83&amp;url=/archives/1549683494970" width="1" height="1" alt="" style="opacity:0;">案例：MapReduceDemoREADME中给出了对应知识点Mapper阶段用户自定义的Mappe]]></description><guid isPermaLink="false">/archives/1549683494970</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Sat, 9 Feb 2019 03:38:00 GMT</pubDate></item><item><title><![CDATA[HDFS回收站]]></title><link>https://x.medemede.cn/archives/1549327361109</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=HDFS%E5%9B%9E%E6%94%B6%E7%AB%99&amp;url=/archives/1549327361109" width="1" height="1" alt="" style="opacity:0;">默认回收站默认值fs.trash.interval=0，0表示禁用回收站，可以设置删除文件的存活时间]]></description><guid isPermaLink="false">/archives/1549327361109</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Tue, 5 Feb 2019 00:42:45 GMT</pubDate></item><item><title><![CDATA[HDFS快照管理]]></title><link>https://x.medemede.cn/archives/1549326430317</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=HDFS%E5%BF%AB%E7%85%A7%E7%AE%A1%E7%90%86&amp;url=/archives/1549326430317" width="1" height="1" alt="" style="opacity:0;">快照相当于对目录做一个备份。并不会立即复制所有文件，而是指向同一个文件。当写入发生时，才会产生新文件]]></description><guid isPermaLink="false">/archives/1549326430317</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Tue, 5 Feb 2019 00:36:24 GMT</pubDate></item><item><title><![CDATA[Hadoop存档]]></title><link>https://x.medemede.cn/archives/1549326327878</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=Hadoop%E5%AD%98%E6%A1%A3&amp;url=/archives/1549326327878" width="1" height="1" alt="" style="opacity:0;">理论概述每个文件均按块存储，每个块的元数据存储在namenode的内存中，因此hadoop存储小文件]]></description><guid isPermaLink="false">/archives/1549326327878</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Tue, 5 Feb 2019 00:25:00 GMT</pubDate></item><item><title><![CDATA[集群间数据拷贝]]></title><link>https://x.medemede.cn/archives/1549326096765</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=%E9%9B%86%E7%BE%A4%E9%97%B4%E6%95%B0%E6%8D%AE%E6%8B%B7%E8%B4%9D&amp;url=/archives/1549326096765" width="1" height="1" alt="" style="opacity:0;">scp实现两个远程主机之间的文件复制scp-rhello.txtroot@hadoop103:/he]]></description><guid isPermaLink="false">/archives/1549326096765</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Tue, 5 Feb 2019 00:21:44 GMT</pubDate></item><item><title><![CDATA[DataNode的版本号]]></title><link>https://x.medemede.cn/archives/1549267021993</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=DataNode%E7%9A%84%E7%89%88%E6%9C%AC%E5%8F%B7&amp;url=/archives/1549267021993" width="1" height="1" alt="" style="opacity:0;">和namenode不同的是，datanode的存储目录是初始阶段自动创建的，不需要额外格式化。查看D]]></description><guid isPermaLink="false">/archives/1549267021993</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Mon, 4 Feb 2019 07:57:34 GMT</pubDate></item><item><title><![CDATA[DataNode工作机制]]></title><link>https://x.medemede.cn/archives/1549266291195</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=DataNode%E5%B7%A5%E4%BD%9C%E6%9C%BA%E5%88%B6&amp;url=/archives/1549266291195" width="1" height="1" alt="" style="opacity:0;">工作机制一个数据块在datanode上以文件形式存储在磁盘上，包括两个文件，一个是数据本身，一个是元]]></description><guid isPermaLink="false">/archives/1549266291195</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Mon, 4 Feb 2019 07:50:06 GMT</pubDate></item><item><title><![CDATA[服役和退役数据节点]]></title><link>https://x.medemede.cn/archives/1549249276517</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=%E6%9C%8D%E5%BD%B9%E5%92%8C%E9%80%80%E5%BD%B9%E6%95%B0%E6%8D%AE%E8%8A%82%E7%82%B9&amp;url=/archives/1549249276517" width="1" height="1" alt="" style="opacity:0;">服役新数据节点环境准备克隆一台虚拟机修改ip地址和主机名称修改xcall和xsync文件，增加新增节]]></description><guid isPermaLink="false">/archives/1549249276517</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Mon, 4 Feb 2019 03:01:00 GMT</pubDate></item><item><title><![CDATA[NameNode版本号]]></title><link>https://x.medemede.cn/archives/1549247861909</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=NameNode%E7%89%88%E6%9C%AC%E5%8F%B7&amp;url=/archives/1549247861909" width="1" height="1" alt="" style="opacity:0;">查看NameNode版本号在{HADOOP_HOME}/data/tmp/dfs/name/curr]]></description><guid isPermaLink="false">/archives/1549247861909</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Mon, 4 Feb 2019 02:37:48 GMT</pubDate></item><item><title><![CDATA[集群安全模式操作]]></title><link>https://x.medemede.cn/archives/1549196656846</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=%E9%9B%86%E7%BE%A4%E5%AE%89%E5%85%A8%E6%A8%A1%E5%BC%8F%E6%93%8D%E4%BD%9C&amp;url=/archives/1549196656846" width="1" height="1" alt="" style="opacity:0;">Namenode启动时，首先将映像文件（fsimage）载入内存，并执行编辑日志（edits）中的各]]></description><guid isPermaLink="false">/archives/1549196656846</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Sun, 3 Feb 2019 12:28:11 GMT</pubDate></item><item><title><![CDATA[从SecondaryNameNode恢复数据]]></title><link>https://x.medemede.cn/archives/1549194015178</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=%E4%BB%8ESecondaryNameNode%E6%81%A2%E5%A4%8D%E6%95%B0%E6%8D%AE&amp;url=/archives/1549194015178" width="1" height="1" alt="" style="opacity:0;">SecondaryNameNode用来监控HDFS状态的辅助后台程序，每隔一段时间获取HDFS元数据]]></description><guid isPermaLink="false">/archives/1549194015178</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Sun, 3 Feb 2019 11:53:00 GMT</pubDate></item><item><title><![CDATA[HDFS镜像文件和编辑日志文件]]></title><link>https://x.medemede.cn/archives/1549186374579</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=HDFS%E9%95%9C%E5%83%8F%E6%96%87%E4%BB%B6%E5%92%8C%E7%BC%96%E8%BE%91%E6%97%A5%E5%BF%97%E6%96%87%E4%BB%B6&amp;url=/archives/1549186374579" width="1" height="1" alt="" style="opacity:0;">fsimage&amp;amp;editsNameNode被格式化之后，将在{Hadoop_HOME}/da]]></description><guid isPermaLink="false">/archives/1549186374579</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Sun, 3 Feb 2019 09:41:00 GMT</pubDate></item><item><title><![CDATA[NameNode&Secondary NameNode工作机制]]></title><link>https://x.medemede.cn/archives/1549185806501</link><description><![CDATA[<img src="https://x.medemede.cn/plugins/feed/assets/telemetry.gif?title=NameNode%26Secondary%20NameNode%E5%B7%A5%E4%BD%9C%E6%9C%BA%E5%88%B6&amp;url=/archives/1549185806501" width="1" height="1" alt="" style="opacity:0;">第一阶段：namenode启动1.第一次启动namenode格式化后，创建fsimage和edits]]></description><guid isPermaLink="false">/archives/1549185806501</guid><dc:creator>Saber</dc:creator><category>JAVA</category><category>Hadoop</category><pubDate>Sun, 3 Feb 2019 09:29:00 GMT</pubDate></item></channel></rss>