https://blog.youkuaiyun.com/Java_Hadoopzh-cnhttps://blog.youkuaiyun.com/https://blog.youkuaiyun.com/Java_Hadoop/article/details/126337711https://blog.youkuaiyun.com/Java_Hadoop/article/details/126337711Java_HadoopSun, 14 Aug 2022 22:46:34 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/125826897https://blog.youkuaiyun.com/Java_Hadoop/article/details/125826897Java_HadoopSat, 16 Jul 2022 23:45:56 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/121067192https://blog.youkuaiyun.com/Java_Hadoop/article/details/121067192Java_HadoopSun, 31 Oct 2021 17:39:15 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/120056244https://blog.youkuaiyun.com/Java_Hadoop/article/details/120056244Java_HadoopThu, 02 Sep 2021 10:52:07 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/109675861https://blog.youkuaiyun.com/Java_Hadoop/article/details/109675861Java_HadoopFri, 13 Nov 2020 15:29:35 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/103287737https://blog.youkuaiyun.com/Java_Hadoop/article/details/103287737Java_HadoopThu, 28 Nov 2019 09:45:29 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/103283932https://blog.youkuaiyun.com/Java_Hadoop/article/details/103283932Java_HadoopWed, 27 Nov 2019 21:36:13 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/84335368https://blog.youkuaiyun.com/Java_Hadoop/article/details/84335368Java_HadoopThu, 22 Nov 2018 10:47:32 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/77900276https://blog.youkuaiyun.com/Java_Hadoop/article/details/77900276Java_HadoopFri, 08 Sep 2017 22:57:34 +0800性能区别:       OpenSession效率非常低,每次请求可能会执行多个功能,每个功能都是使用OpenSession,这样会反复的连接数据库,效率低        getCurrentSession首先从当前线程中查询是否有可用的session,如果有直接拿来使用,如果没有,新打开一个,并把他放入当前线程中  2>事务对其影响的差别:       getCurrentSessi]]>https://blog.youkuaiyun.com/Java_Hadoop/article/details/77899822https://blog.youkuaiyun.com/Java_Hadoop/article/details/77899822Java_HadoopFri, 08 Sep 2017 22:40:46 +0800一级缓存 在查询的时候,每次都会先去session容器中找是否需要的对象,如果有,直接返回,不会与数据库进行交互 如果session容器中没有,session向数据库中查询,这时会与数据库进行交互,发送sql语句. 一级缓存是Session级别的缓存。在操作数据库时需要构造Session对象，在对象中有一个数据结构（HashMap）用于存储缓存数据。不同的Session之间的缓存]]>https://blog.youkuaiyun.com/Java_Hadoop/article/details/76692019https://blog.youkuaiyun.com/Java_Hadoop/article/details/76692019Java_HadoopFri, 04 Aug 2017 19:43:24 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/76546514https://blog.youkuaiyun.com/Java_Hadoop/article/details/76546514Java_HadoopTue, 01 Aug 2017 17:10:09 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/75645484https://blog.youkuaiyun.com/Java_Hadoop/article/details/75645484Java_HadoopFri, 21 Jul 2017 14:27:41 +0800method="get"       提交时传递的值暴露在url上       http://localhost:8080/Web-ServletContext/Servlet_Context?name=王经   2>method="post"      post方式不会暴露传递的值,而且传递的数据量比get大        http://localhost:8080/Web-Servl]]>https://blog.youkuaiyun.com/Java_Hadoop/article/details/75640473https://blog.youkuaiyun.com/Java_Hadoop/article/details/75640473Java_HadoopFri, 21 Jul 2017 13:39:14 +0800200  :请求成功     2>302  :请求重定向     3>304  :请求资源没有改变,访问本地缓存     4>404  :请求资源不存在,通常是访问路径错误(重新输入正确路径)     5>500  :服务器内部错误,一般都是程序中的代码错误(直接去查看代码,改正错误)]]>https://blog.youkuaiyun.com/Java_Hadoop/article/details/75365046https://blog.youkuaiyun.com/Java_Hadoop/article/details/75365046Java_HadoopWed, 19 Jul 2017 12:45:07 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/75364914https://blog.youkuaiyun.com/Java_Hadoop/article/details/75364914Java_HadoopWed, 19 Jul 2017 12:39:59 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/75208526https://blog.youkuaiyun.com/Java_Hadoop/article/details/75208526Java_HadoopSun, 16 Jul 2017 17:49:22 +0800https://blog.youkuaiyun.com/Java_Hadoop/article/details/75107817https://blog.youkuaiyun.com/Java_Hadoop/article/details/75107817Java_HadoopFri, 14 Jul 2017 14:27:27 +0800