<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[apple_5的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/apple_5</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; apple_5]]></copyright><item><title><![CDATA[安装  win]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/80714045</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/80714045</guid><author>apple_5</author><pubDate>Sat, 16 Jun 2018 17:25:47 +0800</pubDate><description><![CDATA[1. 下载redis  选zip包https://github.com/MicrosoftArchive/redis/releases2. 解压  例如目录：  c: /redis3. 切换到命令行 在c:/redis  下执行    redis-server redis.windows.conf  下图表示成功4. 注册redis为服务（否则cmd窗口关闭 redis服务就停了）（1）依旧在命令...]]></description><category></category></item><item><title><![CDATA[python安装]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/80713138</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/80713138</guid><author>apple_5</author><pubDate>Sat, 16 Jun 2018 15:35:21 +0800</pubDate><description><![CDATA[win:1.  https://www.python.org/2. 下载后直接运行   注意勾上add python to path3. cmd窗口输入  python  出现下图就成功了，没成功就检查下环境变量]]></description><category></category></item><item><title><![CDATA[关于数据库的坑1]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/80713088</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/80713088</guid><author>apple_5</author><pubDate>Sat, 16 Jun 2018 15:11:17 +0800</pubDate><description><![CDATA[各位好：    在今天排查磁盘使用率异常时，我们发现一条慢SQL造成大量的物理IO读操作，严重消耗服务器IO资源。该慢SQL类似于：SELECTUID,COUNT(1)AS UID_COUNTFROMTB_XXXXXWHEREUID IN(’XXX’,’XXX’,’XXX’,)GROUPBY UID 应用程序在IN子查询中传入超过22000个UID值，整个SQL语句超过45000行，执行时间超过1...]]></description><category></category></item><item><title><![CDATA[在IoC容器中装配Bean]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/76398233</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/76398233</guid><author>apple_5</author><pubDate>Sun, 30 Jul 2017 17:20:28 +0800</pubDate><description><![CDATA[装配一个Beanxml<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http]]></description><category></category></item><item><title><![CDATA[遇到的报错]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/76377290</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/76377290</guid><author>apple_5</author><pubDate>Sun, 30 Jul 2017 13:19:57 +0800</pubDate><description><![CDATA[jsp页面通过jstl无法接收Spring MVC参数 
在web-app标签中加入以下属性<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"  
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
xsi:schemaLocation="http://java.]]></description><category></category></item><item><title><![CDATA[zookeeper客户端]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/73246286</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/73246286</guid><author>apple_5</author><pubDate>Wed, 14 Jun 2017 16:21:46 +0800</pubDate><description><![CDATA[客户端指令： 
在zk中，每一次对数据节点的写操作，被认为是一次事务，每一个事务系统都会分配一个事务id，来标识这个事务查询相关指令ls / 
ls /node1 
列出某节点下面子节点的信息stat 
获取某节点的状态信息get 
获取当前节点的数据内容ls2 
列出某节点下面子节点的信息、即当前节点的状态创建相关指令（一个）create [-s]  [-e]  path data  acl 
-]]></description><category></category></item><item><title><![CDATA[kafka初认识]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/73196177</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/73196177</guid><author>apple_5</author><pubDate>Tue, 13 Jun 2017 22:38:58 +0800</pubDate><description><![CDATA[集群配置修改配置文件server.properties（在两台或多台上做同样的处理  broker.id   分别配0  1  2 三台 ）broker.id =0  当前机器序号0 
num.io.threads=2 
若log.dir有多个目录，那么该配置数应大于目录数，性能好一些 
log.dir 
消息持久化的目录，多个目录可用逗号隔开 
持久化的时候，看哪个目录分区数最少，就放哪个 
so]]></description><category></category></item><item><title><![CDATA[activeMQ]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/73188804</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/73188804</guid><author>apple_5</author><pubDate>Tue, 13 Jun 2017 17:26:54 +0800</pubDate><description><![CDATA[特性多种语言和协议编写客户端。语言: Java, C, C++, C#, Ruby, Perl, Python, PHP。应用协议: OpenWire,Stomp REST,WS Notification,XMPP,AMQP  
完全支持JMS1.1和J2EE 1.4规范 (持久化,XA消息,事务)  
对Spring的支持,ActiveMQ可以很容易内嵌到使用Spring的系统里面去,而且也支持S]]></description><category></category></item><item><title><![CDATA[消息队列]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/73162839</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/73162839</guid><author>apple_5</author><pubDate>Tue, 13 Jun 2017 10:26:17 +0800</pubDate><description><![CDATA[http://blog.youkuaiyun.com/he90227/article/details/508006461.概述消息队列中间件是分布式系统中重要的组件，主要解决应用耦合，异步消息，流量削锋等问题。实现高性能，高可用，可伸缩和最终一致性架构。是大型分布式系统不可缺少的中间件。 
目前在生产环境，使用较多的消息队列有ActiveMQ，RabbitMQ，ZeroMQ，Kafka，MetaMQ，Rocke]]></description><category></category></item><item><title><![CDATA[Mybatis-动态sql-17]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72993883</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72993883</guid><author>apple_5</author><pubDate>Sat, 10 Jun 2017 17:04:34 +0800</pubDate><description><![CDATA[if根据传进来的参数情况进行查询<!--• if-->
    <!--• choose (when, otherwise)-->
    <!--• trim (where, set) • foreach--><!--查询员工,要求携带了哪个字段查询条件就带上这个字段的值-->
    <!--public List<Employee> getEmpsByConditionIf(Employee]]></description><category></category></item><item><title><![CDATA[mybatis-分步查询方式传递多列的值-16]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72954128</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72954128</guid><author>apple_5</author><pubDate>Fri, 09 Jun 2017 10:12:24 +0800</pubDate><description><![CDATA[分步查询方式，需要传多列值如果需要将多列的值传递过去，可以封装map传递 
column=”{key1=column1,key2=column2}”// fetchType:  有两个选项lazy  eager  可以设置立即加载或延迟加载 
//  下面的deptId是com.stayreal.mybatis.EmployeeMapperPlus.getEmpsByDeptId方法中接收的参数名<]]></description><category></category></item><item><title><![CDATA[mybatis-查询（resultMap,关联集合）-15]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72953946</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72953946</guid><author>apple_5</author><pubDate>Fri, 09 Jun 2017 10:00:13 +0800</pubDate><description><![CDATA[场景：查询部门下的所有员工第一种方式：嵌套结果集方式 
第二种方式：分步查询方式第一种方式：嵌套结果集方式javaBeanpublic class Department {
    private Integer id;
    private String name;
    private List<Employee> employees;}接口public Department getDepa]]></description><category></category></item><item><title><![CDATA[mybatis-查询（resultMap,关联单个对象）-14]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72953878</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72953878</guid><author>apple_5</author><pubDate>Fri, 09 Jun 2017 09:54:09 +0800</pubDate><description><![CDATA[第一种方式：嵌套结果集方式 
第二种方式：分步查询方式,通过association定义联合的对象 
第三种方式：使用association分步查询场景：查出employee同时查出部门，employee–>departmentjavaBean和表public class Employee {
    private Integer id;
    private String lastName;]]></description><category></category></item><item><title><![CDATA[mybatis-查询（resultMap  自定义结果集）-13]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72953731</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72953731</guid><author>apple_5</author><pubDate>Fri, 09 Jun 2017 09:41:39 +0800</pubDate><description><![CDATA[resultType是自动封装的，当resultType满足不了时: 
1.驼峰命名法  2. resultMapresultMap  自定义结果集  强大且重要关闭驼峰命名法法测试public Employee getEmpById(Integer id);<!-- 自定义某个javaBean的封装规则
    type:自定义规则的java类型
    id:唯一方便引用
    -->]]></description><category></category></item><item><title><![CDATA[mybatis-查询（自动封装得resultType）-12]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72953681</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72953681</guid><author>apple_5</author><pubDate>Fri, 09 Jun 2017 09:37:26 +0800</pubDate><description><![CDATA[resultType是自动封装的查询listpublic List<Employee> getEmpsByLastName(String lastName);<select id="getEmpsByLastName" resultType="com.stayreal.mybatis.Employee">
    select * from tbl_employee where last_name]]></description><category></category></item><item><title><![CDATA[mysql-性能优化]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72909683</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72909683</guid><author>apple_5</author><pubDate>Thu, 08 Jun 2017 07:03:37 +0800</pubDate><description><![CDATA[表的优化与列类型选择空间换时间，时间换空间表的优化1.定长与变长分离 
 如id   int占4个字节  char（4） 也占4个字节，这样在磁盘上好查找 
核心且常用的字段   宜放在同一张表varchar\text\blob变长字段适合单放一张表，用主键与核心表关联起来 
2. 常用字段和不常用字段分离 
3. 在一对多关系中，在一的一方增加冗余字段 
例如：catelog下有多条topic,统]]></description><category></category></item><item><title><![CDATA[mybatis-参数处理-11]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72902622</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72902622</guid><author>apple_5</author><pubDate>Wed, 07 Jun 2017 18:05:01 +0800</pubDate><description><![CDATA[参数处理]]></description><category></category></item><item><title><![CDATA[mybatis-sql映射文件-获取自增主键值-1]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72901859</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72901859</guid><author>apple_5</author><pubDate>Wed, 07 Jun 2017 17:05:50 +0800</pubDate><description><![CDATA[EmployeeMapper.xml <!--
    mysql支持自增主键，自增主键值的获取，mybatis也是利用statement.getGeneratoredKeys(),
    useGeneratedKeys="true",使用自增主键策略
    keyProperty:指定对应的主键属性，也就是mybatis获取到的主键值给javabean的哪个属性
    -->
    <i]]></description><category></category></item><item><title><![CDATA[mybatis-sql映射文件-CRUD-1]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72901680</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72901680</guid><author>apple_5</author><pubDate>Wed, 07 Jun 2017 16:54:48 +0800</pubDate><description><![CDATA[非常重要： 
CRUD 
sql映射文件： <!--public void addEmp(Employee employee); parameterType可省略-->
    <insert id="addEmp" parameterType="com.stayreal.mybatis.Employee">
        insert into tbl_employee(last_name,em]]></description><category></category></item><item><title><![CDATA[mybatis-全局配置文件-mybatis-config.xml-mappers-10]]></title><link>https://blog.youkuaiyun.com/apple_5/article/details/72899572</link><guid>https://blog.youkuaiyun.com/apple_5/article/details/72899572</guid><author>apple_5</author><pubDate>Wed, 07 Jun 2017 14:39:28 +0800</pubDate><description><![CDATA[推荐：比较重要的，复杂的Dao接口来写sql映射文件  
          不重要的，简单的为了开发快速使用注解    <!-- 将sql映射注册到全局配置中-->
    <mappers>
        <!-- resource：引用类路径下的文件
             url：引用磁盘路径下的资源
              <mapper url="file:///var/mapp]]></description><category></category></item></channel></rss>