视频网站 基础架构存储 视频网站后端架构

一、视频架构模式

1. 自建模式(自己去搭建视频云服务器。因为占服务器的宽带，所以传统服务器不能做视频服务器，需要自己搭建视频服务器)：
   　　需要跟电信运营商拉专线，还要配置CDN(加速用，就是内容分发，大型网站的高并发解决方案的一个理念)、防盗链、缓存、提供给移动APP的接口(SDK)等，所以一般都是使用第三方视频接口，它们拥有成熟的视频解决方案， 解决拉专线和配置的问题。
   　　PS：内容分发：其实就是将多台服务器部署在不同地区，就近进行访问。
2. 第三方模式：
   　　使用第三方云视频接口：阿里云、保利云(8毛)、乐视云(4毛G)。

二、SSM项目整合

1. 分布式与分模块开发的区别？
   分布式：一个项目拆分不同的项目进行部署开发，通过http协议进行通讯–微服务。
   分模块开发：一个项目拆分成了子工程、父工程，通过jar包进行通讯。
2. 整合思路：

1. 引入jar包。
2. Spring整合SpringMVC， 建立springmcv核心加载配置文件，配置包路径扫描、视图转发器、转换json格式、上传图片等，并在web.xml中加载springmvc.xml。
3. Spring整合Mybatis，建立spring其它配置文件，配置包扫描、数据源等。

3. 分模块开发，SSM环境搭建：

1. 创建maven工程的父子依赖关系：
   videowebsite-parent–父工程，打包方式pom，管理jar包的版本号，项目中所有工程都应该继承父工程。
   videowebsite-commons–通用的工具类通用的pojo，打包方式jar。
   videowebsite-dao–数据库访问层(持久化层)，打包方式jar。
   videowebsite-service–服务层，打包方式jar。
   videowebsite-entity–实体类，打包方式jar。
   videowebsite-web–表现层工程，打包方式war。
2. 在videowebsite-parent父工程中为pom.xml添加maven依赖：

<!-- 集中定义依赖版本号 -->
<properties>
	<junit.version>4.12</junit.version>
	<spring.version>5.1.6.RELEASE</spring.version>
	<mybatis.version>3.5.1</mybatis.version>
	<mybatis.spring.version>2.0.1</mybatis.spring.version>
	<mybatis.paginator.version>1.2.17</mybatis.paginator.version>
	<mysql.version>8.0.15</mysql.version>
	<slf4j.version>1.7.26</slf4j.version>
	<jackson.version>2.9.8</jackson.version>
	<druid.version>1.1.16</druid.version>
	<httpclient.version>4.5.8</httpclient.version>
	<jstl.version>1.2</jstl.version>
	<servlet-api.version>3.0-alpha-1</servlet-api.version>
	<jsp-api.version>2.0</jsp-api.version>
	<joda-time.version>2.10.1</joda-time.version>
	<commons-lang3.version>3.9</commons-lang3.version>
	<commons-io.version>2.6</commons-io.version>
	<commons-net.version>3.6</commons-net.version>
	<pagehelper.version>5.1.8</pagehelper.version>
	<jsqlparser.version>0.9.1</jsqlparser.version>
	<commons-fileupload.version>1.4</commons-fileupload.version>
	<jedis.version>3.1.0-m1</jedis.version>
	<solrj.version>4.10.3</solrj.version>
</properties>
<dependencyManagement>
	<dependencies>
		<!-- 时间操作组件 -->
		<dependency>
			<groupId>joda-time</groupId>
			<artifactId>joda-time</artifactId>
			<version>${joda-time.version}</version>
		</dependency>
		<!-- Apache工具组件 -->
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-lang3</artifactId>
			<version>${commons-lang3.version}</version>
		</dependency>
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-io</artifactId>
			<version>${commons-io.version}</version>
		</dependency>
		<dependency>
			<groupId>commons-net</groupId>
			<artifactId>commons-net</artifactId>
			<version>${commons-net.version}</version>
		</dependency>
		<!-- Jackson Json处理工具包 -->
		<dependency>
			<groupId>com.fasterxml.jackson.core</groupId>
			<artifactId>jackson-databind</artifactId>
			<version>${jackson.version}</version>
		</dependency>
		<!-- httpclient -->
		<dependency>
			<groupId>org.apache.httpcomponents</groupId>
			<artifactId>httpclient</artifactId>
			<version>${httpclient.version}</version>
		</dependency>
		<!-- 单元测试 -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>${junit.version}</version>
			<scope>test</scope>
		</dependency>
		<!-- 日志处理 -->
		<dependency>
			<groupId>org.slf4j</groupId>
			<artifactId>slf4j-log4j12</artifactId>
			<version>${slf4j.version}</version>
		</dependency>
		<!-- Mybatis -->
		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis</artifactId>
			<version>${mybatis.version}</version>
		</dependency>
		<dependency>
			<groupId>org.mybatis</groupId>
			<artifactId>mybatis-spring</artifactId>
			<version>${mybatis.spring.version}</version>
		</dependency>
		<dependency>
			<groupId>com.github.miemiedev</groupId>
			<artifactId>mybatis-paginator</artifactId>
			<version>${mybatis.paginator.version}</version>
		</dependency>
		<dependency>
			<groupId>com.github.pagehelper</groupId>
			<artifactId>pagehelper</artifactId>
			<version>${pagehelper.version}</version>
		</dependency>
		<!-- MySql -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<version>${mysql.version}</version>
		</dependency>
		<!-- 连接池 -->
		<dependency>
			<groupId>com.alibaba</groupId>
			<artifactId>druid</artifactId>
			<version>${druid.version}</version>
		</dependency>
		<!-- Spring -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-beans</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-webmvc</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-jdbc</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-aspects</artifactId>
			<version>${spring.version}</version>
		</dependency>
		<!-- JSP相关 -->
		<dependency>
			<groupId>jstl</groupId>
			<artifactId>jstl</artifactId>
			<version>${jstl.version}</version>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>servlet-api</artifactId>
			<version>${servlet-api.version}</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>javax.servlet</groupId>
			<artifactId>jsp-api</artifactId>
			<version>${jsp-api.version}</version>
			<scope>provided</scope>
		</dependency>
		<!-- 文件上传组件 -->
		<dependency>
			<groupId>commons-fileupload</groupId>
			<artifactId>commons-fileupload</artifactId>
			<version>${commons-fileupload.version}</version>
		</dependency>
		<!-- Redis客户端 -->
		<dependency>
			<groupId>redis.clients</groupId>
			<artifactId>jedis</artifactId>
			<version>${jedis.version}</version>
		</dependency>
	</dependencies>
</dependencyManagement>

<build>
	<finalName>${project.artifactId}</finalName>
	<plugins>
		<!-- 资源文件拷贝插件 -->
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-resources-plugin</artifactId>
			<version>2.7</version>
			<configuration>
				<encoding>UTF-8</encoding>
			</configuration>
		</plugin>
		<!-- java编译插件 -->
		<plugin>
			<groupId>org.apache.maven.plugins</groupId>
			<artifactId>maven-compiler-plugin</artifactId>
			<version>3.2</version>
			<configuration>
				<source>1.8</source>
				<target>1.8</target>
				<encoding>UTF-8</encoding>
			</configuration>
		</plugin>
	</plugins>
	<pluginManagement>
		<plugins>
			<!-- 配置Tomcat插件 -->
			<plugin>
				<groupId>org.apache.tomcat.maven</groupId>
				<artifactId>tomcat7-maven-plugin</artifactId>
				<version>2.2</version>
			</plugin>
		</plugins>
	</pluginManagement>
</build>

1. Spring整合SpringMVC：
   SpringMVC的执行流程：
   　　SpringMVC的核心是DispatcherServlet类(通过这个类可知SpringMVC的底层就是servlet)，任何请求都会先交给DispatcherServlet进行转发，转发后再分发到某一个请求中去，再拿到转换视图器到某一个页面。

1. 在表现层videowebsite-web工程中为pom.xml引入maven依赖：

<dependencies>
	<dependency>
		<groupId>chauncy</groupId>
		<artifactId>videowebsite-service</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</dependency>
	<!-- JSP相关 -->
	<dependency>
		<groupId>jstl</groupId>
		<artifactId>jstl</artifactId>
	</dependency>
	<dependency>
		<groupId>javax.servlet</groupId>
		<artifactId>servlet-api</artifactId>
		<scope>provided</scope>
	</dependency>
	<dependency>
		<groupId>javax.servlet</groupId>
		<artifactId>jsp-api</artifactId>
		<scope>provided</scope>
	</dependency>
	<!-- 文件上传组件 -->
	<dependency>
		<groupId>commons-fileupload</groupId>
		<artifactId>commons-fileupload</artifactId>
	</dependency>
	<!-- springwebmvc -->
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-webmvc</artifactId>
	</dependency>
	<dependency>
		<groupId>chauncy</groupId>
		<artifactId>videowebsite-entity</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-annotations</artifactId>
		<version>2.9.8</version>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-core</artifactId>
		<version>2.9.8</version>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.core</groupId>
		<artifactId>jackson-databind</artifactId>
	</dependency>
	<dependency>
		<groupId>com.fasterxml.jackson.jr</groupId>
		<artifactId>jackson-jr-all</artifactId>
		<version>2.9.8</version>
	</dependency>
</dependencies>

1. 新增springmvc.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- springmvc 扫包范围 -->
    <context:component-scan base-package="chauncy.controller" />
    <!-- 开启springmvc注解 -->
    <mvc:annotation-driven />
    <!-- 视图跳转类型 -->
    <bean
        class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

1. web.xml加载SpringMVC配置文件：

<!-- 解决post乱码 -->
<filter>
	<filter-name>CharacterEncodingFilter</filter-name>
	<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
	<init-param>
		<param-name>encoding</param-name>
		<param-value>UTF-8</param-value>
	</init-param>
	<!-- <init-param> <param-name>forceEncoding</param-name> <param-value>true</param-value> 
		</init-param> -->
</filter>
<filter-mapping>
	<filter-name>CharacterEncodingFilter</filter-name>
	<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- springmvc的前端控制器 -->
<servlet>
	<servlet-name>videowebsite-web</servlet-name>
	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
	<!-- contextConfigLocation不是必须的， 如果不配置contextConfigLocation， springmvc的配置文件默认在：WEB-INF/servlet的name+"-servlet.xml" -->
	<init-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>classpath:spring/springmvc.xml</param-value>
	</init-param>
	<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
	<servlet-name>videowebsite-web</servlet-name>
	<url-pattern>/</url-pattern>
</servlet-mapping>

1. Spring整合Mybatis：

1. 创建视频类型、视频详情表：

--视频类型表
CREATE TABLE `video_type` (
  `id` int(11) PRIMARY KEY  NOT NULL AUTO_INCREMENT COMMENT '主键(自增长)',
  `type_name` varchar(30) DEFAULT NULL COMMENT '视频类型'
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;

--视频详情表
CREATE TABLE `video_info` (
  `id` int(11) PRIMARY KEY NOT NULL AUTO_INCREMENT COMMENT '主键(自增长)',
  `video_name` varchar(150) DEFAULT NULL COMMENT '视频名称',
  `video_url` varchar(100) DEFAULT NULL COMMENT '封面图片',
  `video_html` varchar(500) DEFAULT NULL COMMENT '视频html执行元素',
  `video_type_id` int DEFAULT NULL COMMENT '关联typeID',
  `video_del` INT DEFAULT 0 COMMENT '是否显示 0显示 1隐藏'
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8;

1. 在持久化层videowebsite-dao工程中为pom.xml引入maven依赖：

<!-- 依赖管理 -->
<dependencies>
	<dependency>
		<groupId>chauncy</groupId>
		<artifactId>videowebsite-entity</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</dependency>
	<!-- Mybatis -->
	<dependency>
		<groupId>org.mybatis</groupId>
		<artifactId>mybatis</artifactId>
	</dependency>
	<dependency>
		<groupId>org.mybatis</groupId>
		<artifactId>mybatis-spring</artifactId>
	</dependency>
	<dependency>
		<groupId>com.github.miemiedev</groupId>
		<artifactId>mybatis-paginator</artifactId>
	</dependency>
	<dependency>
		<groupId>com.github.pagehelper</groupId>
		<artifactId>pagehelper</artifactId>
	</dependency>
	<!-- MySql -->
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
	</dependency>
	<!-- 连接池 -->
	<dependency>
		<groupId>com.alibaba</groupId>
		<artifactId>druid</artifactId>
	</dependency>
</dependencies>
<!-- 如果不添加此节点mybatis的mapper.xml文件都会被漏掉。 -->
<build>
	<resources>
		<resource>
			<directory>src/main/java</directory>
			<includes>
				<include>**/*.properties</include>
				<include>**/*.xml</include>
			</includes>
			<filtering>false</filtering>
		</resource>
	</resources>
</build>

1. 在服务层videowebsite-service工程中为pom.xml引入maven依赖：

<dependencies>
	<dependency>
		<groupId>chauncy</groupId>
		<artifactId>videowebsite-dao</artifactId>
		<version>0.0.1-SNAPSHOT</version>
	</dependency>
	<!-- Spring -->
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-context</artifactId>
	</dependency>
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-beans</artifactId>
	</dependency>
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-jdbc</artifactId>
	</dependency>
	<dependency>
		<groupId>org.springframework</groupId>
		<artifactId>spring-aspects</artifactId>
	</dependency>
	<!-- 日志处理 -->
	<dependency>
		<groupId>org.slf4j</groupId>
		<artifactId>slf4j-log4j12</artifactId>
	</dependency>
</dependencies>

1. 在表现层videowebsite-web工程中新增applicationContext-service.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
    <!-- 开启spring注解扫描范围，扫描service包下注解 -->
    <context:component-scan base-package="chauncy.service"></context:component-scan>
</beans>

1. 在表现层videowebsite-web工程中新增db.properties：

jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.host=localhost
jdbc.database=architect
jdbc.userName=root
jdbc.passWord=root
jdbc.initialSize=0  
jdbc.maxActive=20    
jdbc.maxIdle=20  
jdbc.minIdle=1  
jdbc.maxWait=1000

1. 在表现层videowebsite-web工程中新增applicationContext-dao.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

    <!-- 数据库连接池 -->
    <!-- 加载配置文件 -->
    <context:property-placeholder location="classpath:properties/*.properties" />
    <!-- 数据库连接池 -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
        destroy-method="close">
    <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url"
            value="jdbc:mysql://${jdbc.host}:3306/${jdbc.database}?serverTimezone=GMT&useUnicode=true&characterEncoding=utf-8&zeroDateTimeBehavior=convertToNull" />
        <property name="username" value="${jdbc.userName}" />
        <property name="password" value="${jdbc.passWord}" />
        <!-- 初始化连接大小 -->
        <property name="initialSize" value="${jdbc.initialSize}"></property>
        <!-- 连接池最大数量 -->
        <property name="maxActive" value="${jdbc.maxActive}"></property>
        <!-- 连接池最大空闲 -->
        <property name="maxIdle" value="${jdbc.maxIdle}"></property>
        <!-- 连接池最小空闲 -->
        <property name="minIdle" value="${jdbc.minIdle}"></property>
    </bean>

     <!-- spring和MyBatis完美整合，不需要mybatis的配置映射文件 -->  
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  
        <property name="dataSource" ref="dataSource" />  
        <!-- 自动扫描mapping.xml文件 -->  
        <property name="mapperLocations" value="classpath:mappings/*.xml"></property>  
    </bean>  
  
    <!-- DAO接口所在包名，Spring会自动查找其下的类 -->  
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">  
        <property name="basePackage" value="chauncy.dao" />  
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>  
    </bean>  
  
</beans>

1. 在表现层videowebsite-web工程中新增applicationContext-dao.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">
    <!-- 事务管理器 -->
    <bean id="transactionManager"
        class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!-- 数据源 -->
        <property name="dataSource" ref="dataSource" />
    </bean>
    <!-- 配置事务增强 -->
    <tx:advice id="txAdvice" transaction-manager="transactionManager">
        <tx:attributes>
            <!-- name：标识哪些方法需要被被事务增强，propagation：配置事务传播行为，read-only：配置是否只是读操作 -->
            <tx:method name="save*" propagation="REQUIRED" />
            <tx:method name="insert*" propagation="REQUIRED" />
            <tx:method name="add*" propagation="REQUIRED" />
            <tx:method name="create*" propagation="REQUIRED" />
            <tx:method name="delete*" propagation="REQUIRED" />
            <tx:method name="update*" propagation="REQUIRED" />
            <tx:method name="find*" propagation="SUPPORTS" read-only="true" />
            <tx:method name="select*" propagation="SUPPORTS" read-only="true" />
            <tx:method name="get*" propagation="SUPPORTS" read-only="true" />
        </tx:attributes>
    </tx:advice>
    <!-- Aop配置： 拦截哪些方法(切入点表表达式) + 应用上面的事务增强配置 -->
    <aop:config>
        <!-- <aop:pointcut expression="execution(* chauncy.service.*.*(..))"
            id="pt" /> -->
        <aop:advisor advice-ref="txAdvice"
            pointcut="execution(* chauncy.service.*.*(..))" />
    </aop:config>
</beans>

1. 使用Mybatis逆向工程生成器生成数据ORM映射文件，并放置到项目中。
2. 实现查询所有视频类型：

package chauncy.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import chauncy.entity.VideoType;
import chauncy.service.VideoTypeServive;

@Controller
@RequestMapping("/VideoTypeController")
public class VideoTypeController {
	
	private static final String TEST="test";
	
	@Autowired
	private VideoTypeServive videoTypeService;
	
	@RequestMapping("/hello")
	public String hello(){
		return TEST;
	}
	
	/**   
	 * @methodDesc: 功能描述(提供一个返回json格式的查询所有VideoType)  
	 * @author: ChauncyWang
	 * @param: @return  
	 * @returnType: List<VideoType>  
	 */  
	@RequestMapping("/getVideoTypeList")
	@ResponseBody
	public List<VideoType> getVideoTypeList(){
		List<VideoType> videoTypes = videoTypeService.getVideoTypes(null);
		for (VideoType videoType : videoTypes) {
			System.out.println(videoType.toString());
		}
		return videoTypes;
	}
}

package chauncy.service;

import java.util.List;

import chauncy.entity.VideoType;

public interface VideoTypeServive {
	
	/**   
	 * @methodDesc: 功能描述(查询所有的视频类型)  
	 * @author: ChauncyWang
	 * @param: @return      
	 * @returnType: List<VideoType>  
	 */  
	public List<VideoType> getVideoTypes(VideoType videoType);
}

package chauncy.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import chauncy.dao.VideoTypeMapper;
import chauncy.entity.VideoType;
import chauncy.service.VideoTypeServive;

@Service
public class VideoTypeServiceImpl implements VideoTypeServive {
	
	@Autowired
	private VideoTypeMapper videoTypeMapper;

	@Override
	public List<VideoType> getVideoTypes(VideoType videoType) {
		return videoTypeMapper.selectList(videoType);
	}

}

package chauncy.dao;

import java.util.List;

import chauncy.entity.VideoType;

public interface VideoTypeMapper {
	int deleteByPrimaryKey(Integer id);

	int insert(VideoType record);

	int insertSelective(VideoType record);

	VideoType selectByPrimaryKey(Integer id);

	int updateByPrimaryKeySelective(VideoType record);

	int updateByPrimaryKey(VideoType record);

	List<VideoType> selectList(VideoType record);
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="chauncy.dao.VideoTypeMapper">
	<resultMap id="BaseResultMap" type="chauncy.entity.VideoType">
		<id column="id" property="id" jdbcType="INTEGER" />
		<result column="type_name" property="typeName" jdbcType="VARCHAR" />
	</resultMap>
	<sql id="Base_Column_List">
		id, type_name
	</sql>
	<select id="selectByPrimaryKey" resultMap="BaseResultMap"
		parameterType="java.lang.Integer">
		select
		<include refid="Base_Column_List" />
		from video_type
		where id = #{id,jdbcType=INTEGER}
	</select>
	<delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
		delete from
		video_type
		where id = #{id,jdbcType=INTEGER}
	</delete>
	<insert id="insert" parameterType="chauncy.entity.VideoType">
		insert into video_type (id,
		type_name)
		values (#{id,jdbcType=INTEGER},
		#{typeName,jdbcType=VARCHAR})
	</insert>
	<insert id="insertSelective" parameterType="chauncy.entity.VideoType">
		insert into video_type
		<trim prefix="(" suffix=")" suffixOverrides=",">
			<if test="id != null">
				id,
			</if>
			<if test="typeName != null">
				type_name,
			</if>
		</trim>
		<trim prefix="values (" suffix=")" suffixOverrides=",">
			<if test="id != null">
				#{id,jdbcType=INTEGER},
			</if>
			<if test="typeName != null">
				#{typeName,jdbcType=VARCHAR},
			</if>
		</trim>
	</insert>
	<update id="updateByPrimaryKeySelective" parameterType="chauncy.entity.VideoType">
		update video_type
		<set>
			<if test="typeName != null">
				type_name = #{typeName,jdbcType=VARCHAR},
			</if>
		</set>
		where id = #{id,jdbcType=INTEGER}
	</update>
	<update id="updateByPrimaryKey" parameterType="chauncy.entity.VideoType">
		update video_type
		set type_name = #{typeName,jdbcType=VARCHAR}
		where id =
		#{id,jdbcType=INTEGER}
	</update>
	<select id="selectList" resultMap="BaseResultMap"
		parameterType="chauncy.entity.VideoType">
		select
		<include refid="Base_Column_List" />
		from video_type
		where
		1=1
		<if test="id != null">
			and #{id,jdbcType=INTEGER},
		</if>
		<if test="typeName != null">
			and #{typeName,jdbcType=VARCHAR},
		</if>

	</select>

</mapper>

1. web.xml配置加载Spring：

<!-- 加载spring容器 -->
<context-param>
	<param-name>contextConfigLocation</param-name>
	<param-value>classpath:spring/applicationContext-*.xml</param-value>
</context-param>
<listener>
	<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

1. 运行结果解决406：
   使用SpringMVC返回json格式,返回状态406,表示SpringMVC没有集成JSON转换器，解决办法：

<!-- 避免IE执行AJAX时,返回JSON出现下载文件 -->
<bean id="mappingJacksonHttpMessageConverter"
	class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
	<property name="supportedMediaTypes">
		<list>
			<value>text/html;charset=UTF-8</value>
		</list>
	</property>
</bean>

<!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->
<bean
	class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
	<property name="messageConverters">
		<list>
			<ref bean="mappingJacksonHttpMessageConverter" /><!-- json转换器 -->
		</list>
	</property>
</bean>

1. Spring整合log4j：
   注：以下配置只限于Spring4.0及以下版本可用，Spring5.0以上需要变更配置方式，在此不做列举。

1. 创建log4j.properties：
   在resources/properties下创建log4j.properties文件

### set log levels ###
log4j.rootLogger =INFO,DEBUG, stdout , R

log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n

log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = D://EclipseWorkspace/EclipseMars2/ArchitectFirstPhase/AllProjectLogs/SSMIntegrationAndVideoWebsiteDevelop.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =D://EclipseWorkspace/EclipseMars2/ArchitectFirstPhase/AllProjectLogs/SSMIntegrationAndVideoWebsiteDevelopError.log
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

1. web.xml加载log4j.properties：

<!--设置log4j的配置文件位置 -->
<context-param>
	<param-name>log4jConfigLocation</param-name>
	<param-value>/WEB-INF/classes/properties/log4j.properties</param-value>
</context-param>
<!--使用监听加载log4j的配置文件 -->
<listener>
	<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
</listener>

1. 在代码中需要日志管理的类使用API：

private static Logger logger = Logger.getLogger(类名.class);

三、视频网站后台管理系统开发实现

1. 实现后台视频查询展示功能：

1. 建立查询jsp页面：

<%@ page language="java" contentType="text/html; charset=utf-8"
	pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>后台视频管理系统</title>
</head>
<body>
	<center>
		<h1>视频网站后台管理系统</h1>
		<a href="locaAddVideo">添加资源</a>
		<table style="BORDER-COLLAPSE: collapse; text-align: center;"
			borderColor=#000000 height=40 cellPadding=1 width="70%"
			align="center" border=1>
			<thead>
				<tr>
					<th>图片</th>
					<th>视频名称</th>
					<th>视频类型</th>
					<th>预览视频</th>
				</tr>
			</thead>
			<tbody>
				<c:forEach items="${listVideo}" var="p">
					<tr style="font-size: 18px">
						<td><img alt="" width="150px;" height="150px;"
							src="/static/imgs/${p.videoUrl}"></td>
						<td>${p.videoName}</td>
						<td>${p.typeName}</td>
						<td><a href="videoDetails?id=${p.id}"
							style='text-decoration: none;'>预览视频</a></td>
					</tr>
				</c:forEach>


			</tbody>
		</table>

	</center>
</body>
</html>

1. 后台代码实现：

package chauncy.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import chauncy.service.VideoInfoService;

@Controller
@RequestMapping("/VideoInfoController")
public class VideoInfoController {
	
	@Autowired
	private VideoInfoService videoInfoService;
	
	private static final String INDEXVIDEO="indexVideo";
	
	/**   
	 * @methodDesc: 功能描述(查询所有视频)  
	 * @author: ChauncyWang
	 * @param: @param httpServletRequest
	 * @param: @param httpServletResponse
	 * @param: @return     
	 * @returnType: String  
	 */  
	@RequestMapping("/indexVideo")
	public String indexVideo(HttpServletRequest httpServletRequest,HttpServletResponse httpServletResponse){
		httpServletRequest.setAttribute("listVideo", videoInfoService.getVideoInfos(null));
		return INDEXVIDEO;
	}
	
}

package chauncy.service;

import java.util.List;

import chauncy.entity.VideoInfo;

public interface VideoInfoService {
	
	public List<VideoInfo> getVideoInfos(VideoInfo videoInfo);
}

package chauncy.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import chauncy.dao.VideoInfoMapper;
import chauncy.entity.VideoInfo;
import chauncy.service.VideoInfoService;

@Service
public class VideoInfoServiceImpl implements VideoInfoService {
	
	@Autowired
	private VideoInfoMapper videoInfoMapper;
	
	@Override
	public List<VideoInfo> getVideoInfos(VideoInfo videoInfo){
		return videoInfoMapper.selectAll(videoInfo);
	}
}

package chauncy.dao;

import java.util.List;

import chauncy.entity.VideoInfo;

public interface VideoInfoMapper {
	List<VideoInfo> selectAll(VideoInfo record);
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="chauncy.dao.VideoInfoMapper">
	<resultMap id="BaseResultMap" type="chauncy.entity.VideoInfo">
		<id column="id" property="id" jdbcType="INTEGER" />
		<result column="video_name" property="videoName" jdbcType="VARCHAR" />
		<result column="video_url" property="videoUrl" jdbcType="VARCHAR" />
		<result column="video_html" property="videoHtml" jdbcType="VARCHAR" />
		<result column="video_type_id" property="videoTypeId" jdbcType="INTEGER" />
		<result column="video_del" property="videoDel" jdbcType="INTEGER" />
	</resultMap>
	<sql id="Base_Column_List">
		id, video_name, video_url, video_html, video_type_id, video_del
	</sql>
	<select id="selectAll" parameterType="chauncy.entity.VideoInfo"
		resultType="chauncy.entity.VideoInfo">
		select a.id as id,a.video_name as videoName, a.video_html as videoHtml
		,a.video_url as videoUrl, a.video_del as videoDel
		, b.type_name as typeName
		from video_info as a inner join video_type as b on a.video_type_id=b.id;
	</select>
</mapper>

1. 静态资源访问404原因：
   需要在springMVC配置文件中配置静态资源。

<!-- 设置允许静态资源访问 -->
<mvc:resources mapping="/static/imgs/**" location="static/imgs/" />
<mvc:resources mapping="/static/easyui/**" location="static/easyui/" />
<mvc:resources mapping="/static/js/**" location="static/js/" />
<mvc:resources mapping="/static/css/**" location="static/css/" />

1. 整合MybatisPageHelper分页插件：

1. 新增mybatis-config.xml文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
	<!-- 配置分页插件 -->
	<plugins>
	    <!-- interceptor的取值，在4.2版本以前：com.github.pagehelper.PageHelper，4.2版本以后，因为改变了实现，取值为：com.github.pagehelper.PageInterceptor -->
		<plugin interceptor="com.github.pagehelper.PageInterceptor">
			<!-- 设置数据库类型 Oracle,Mysql,MariaDB,SQLite,Hsqldb,PostgreSQL六种数据库，PageHelper4.0版本后会自动识别，不用进行配置-->
			<!-- <property name="dialect" value="mysql" /> -->
		</plugin>
	</plugins>
</configuration>

1. 在applicationContext-dao.xml中Mybatis的Sql会话工厂加载mybatis-config.xml：

<!-- spring和MyBatis完美整合，不需要mybatis的配置映射文件 -->  
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  
    <property name="configLocation" value="classpath:spring/mybatis-config.xml" />  
</bean>

1. 在Java代码中使用：

package chauncy.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;

import chauncy.service.VideoInfoService;

@Controller
@RequestMapping("/VideoInfoController")
public class VideoInfoController {
	
	@Autowired
	private VideoInfoService videoInfoService;
	
	private static final String INDEXVIDEO="indexVideo";
	
	/**   
	 * @methodDesc: 功能描述(查询所有视频)  
	 * @author: ChauncyWang
	 * @param: @param httpServletRequest
	 * @param: @param httpServletResponse
	 * @param: @return     
	 * @returnType: String  
	 */  
	@RequestMapping("/indexVideo")
	public String indexVideo(HttpServletRequest httpServletRequest,Integer pageIndex){
		//页数，一定要在dao方法之前使用，第一个参数：页数，不是limit默认起始值0，默认为1，代表limit的0，第二个参数：参数。分页公式：(页数-1)*长度。
		if(pageIndex == null){
			pageIndex=1;
		}
		Page page = PageHelper.startPage(pageIndex, 2);
		httpServletRequest.setAttribute("listVideo", videoInfoService.getVideoInfos(null));
		//获取分页总数
		httpServletRequest.setAttribute("pages", page.getPages());
		return INDEXVIDEO;
	}
	
}

1. 在查询jsp页面中增加前端代码：

<a style="font-size: 20px;" href="indexVideo?pageIndex=1">首页</a>
<c:forEach begin="1" end="${pages}" var="p">
    <a style="font-size: 20px;" href="indexVideo?pageIndex=${p}">${p}</a>
</c:forEach>
<a style="font-size: 20px;" href="indexVideo?pageIndex=${pages}">尾页</a>

1. 实现后台视频详情展示功能：

1. 查询jsp页面详情按钮造成请求：

<td><a href="getVideo?id=${p.id}"
			style='text-decoration: none;'>预览视频</a></td>

1. java代码处理请求返回详情页：

package chauncy.controller;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;

import chauncy.entity.VideoInfo;
import chauncy.service.VideoInfoService;

@Controller
@RequestMapping("/VideoInfoController")
public class VideoInfoController {
	
	@Autowired
	private VideoInfoService videoInfoService;
	
	private static final String INDEXVIDEO="indexVideo";
	private static final String VIDEODETAIL="videoDetail";
	
	/**   
	 * @methodDesc: 功能描述(展示视频详情信息)  
	 * @author: ChauncyWang
	 * @param: @param request
	 * @param: @param id
	 * @param: @return   
	 * @returnType: String  
	 */  
	@RequestMapping("/getVideo")
	public String getVideo(HttpServletRequest request,Integer id){
		VideoInfo videoInfo = videoInfoService.getVideoInfo(id);
		request.setAttribute("videoInfo", videoInfo);
		return VIDEODETAIL;
	}
}

package chauncy.service;

import java.util.List;

import chauncy.entity.VideoInfo;

public interface VideoInfoService {
		public VideoInfo getVideoInfo(int id);
}

package chauncy.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import chauncy.dao.VideoInfoMapper;
import chauncy.entity.VideoInfo;
import chauncy.service.VideoInfoService;

@Service
public class VideoInfoServiceImpl implements VideoInfoService {
	
	@Autowired
	private VideoInfoMapper videoInfoMapper;
	
	@Override
	public VideoInfo getVideoInfo(int id) {
		return videoInfoMapper.selectByPrimaryKey(id);
	}
}

1. 详情页jsp嵌入第三方视频代码展示视频详情相关信息：

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>${videoInfo.videoName}</title>
</head>
<body>
    <h1>${videoInfo.videoName}</h1>
    <iframe src="${videoInfo.videoHtml} }" scrolling="no" border="0" frameborder="no" framespacing="0" allowfullscreen="true"> </iframe>
</body>
</html>

1. 实现SpringMVC的上传图片功能：

1. 在springmvc.xml中添加上传文件配置：

<!-- 支持上传文件 -->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

1. 查询jsp页面添加资源按钮造成请求：

<a href="jumpToAddVideoPage">添加资源</a>

1. java代码处理请求返回添加视频页：

package chauncy.controller;

import javax.servlet.http.HttpServletRequest;
import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import chauncy.service.VideoTypeServive;

@Controller
@RequestMapping("/VideoInfoController")
public class VideoInfoController {
	@Autowired
	private VideoTypeServive videoTypeServive;

	private static final String ADDVIDEO="addVideo";

	@RequestMapping("/jumpToAddVideoPage")
	public String jumpToAddVideoPage(HttpServletRequest request){
		request.setAttribute("listVideoType",videoTypeServive.getVideoTypes(null));
		return ADDVIDEO;
	}
}

<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>添加视频资源</title>
</head>
<body>
    <center>
        <h1>后台添加视频资源</h1>
        <form action="addVideo" style="font-size: 14px;" method="post"
            ENCTYPE="multipart/form-data">
            <table>
                <tr>
                    <td>视频名称:</td>
                    <td><input type="text" name=videoName></td>
                </tr>
                <tr>
                    <td>视频类型:</td>
                    <td><select name="videoTypeId" style="width: 170px;">
                            <c:forEach items="${listVideoType}" var="p">
                                <option value="${p.id}">${p.typeName}</option>
                            </c:forEach>

                    </select></td>
                </tr>
                <tr>
                    <td>B站播放URL:</td>
                    <td><textarea rows="10" cols="30" name="videoHtml"></textarea></td>
                </tr>
                <tr>
                    <td>上传封面:</td>
                    <td><input type="file" name="file"></td>
                </tr>
                <tr> <td colspan="2"><input type="submit" value="提交"></td></tr>
            </table>
        </form>
    </center>
</body>
</html>

1. 添加视频频请求的实现：

package chauncy.controller;

import java.io.File;
import java.io.IOException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;

import chauncy.entity.VideoInfo;
import chauncy.service.VideoInfoService;
import chauncy.service.VideoTypeServive;

@Controller
@RequestMapping("/VideoInfoController")
public class VideoInfoController {
	private static Logger logger = Logger.getLogger(VideoInfoController.class);

	@Autowired
	private VideoInfoService videoInfoService;
	@Autowired
	private VideoTypeServive videoTypeServive;
	
	@RequestMapping("/addVideo")
	public String addVideo(@RequestParam(value="file",required=false)MultipartFile file,VideoInfo videoInfo,HttpServletRequest request){
		//file.getOriginalFilename();//文件的原生名称
		String imageName=System.currentTimeMillis()+".png";//时间戳只是在单个JVM保证不重复，但是在分布式JVM会重复
		//项目环境地质
		String path=request.getSession().getServletContext().getRealPath("/static/imgs");
		logger.info("path:"+path);
		File targetFile = new File(path,imageName);
		if(!targetFile.exists()){
			targetFile.mkdirs();//创建文件夹
			
		}
		try {
			//保存图片
			file.transferTo(targetFile);
		} catch (Exception e) {
			//打印日志一定要用e进行打印，不要用e.getMessage()，因为有时可能为空
			logger.error("saveImagesError--------->"+e);
			request.setAttribute("result", "上传图片失败！");
			return ADDVIDEO;
		}
		videoInfo.setVideoUrl(imageName);
		try {
			//videoInfo.toString()中videoInfo可以允许为空，不抛异常，直接打印空
			logger.info("###videoInfoService start... addVideo()###videoInfo:"+videoInfo.toString());
			int addVideoResult = videoInfoService.addVideo(videoInfo);
			//日志打印中={}表示对应一个参数，多个参数为：={},{}...逗号隔开
			logger.info("###videoInfoService end... addVideo()###addVideoResult={}"+addVideoResult);
			if(addVideoResult<=0){
				request.setAttribute("result", "保存数据错误！");
				return ADDVIDEO;
			}
			return "redirect:/VideoInfoController/indexVideo";
		} catch (Exception e) {
			//打印日志一定要用e进行打印，不要用e.getMessage()，因为有时可能为空
			logger.error("videoInfoServiceAddVideoError--------->"+e);
			request.setAttribute("result", "保存数据错误！");
			return ADDVIDEO;
		}
	}
}

四、扩展知识点：

1. Mysql分页和Oracle分页有什么区别（SqlServer使用top分页，在此不列举）？
   Mysql分页使用limit，Oracle分页使用伪列rownum分页。

1. limit分页
   limit m,n　　m表示起始行，从0开始，n表示取几行。
   例：

select * from stu limit m, n;

1. rownum分页
   rownum只能比较小于，不能比较大于，因为rownum是先查询后排序的，例如查询条件为rownum>1，当查询到第一条数据，rownum为1，则不符合条件。第2、3…类似，一直不符合条件，所以一直没有返回结果。所以查询的时候需要设置别名，然后查询完成之后再通过调用别名进行大于的判断。
   例：

select * from (
select rownum rn,a.* from table_name a where rownum <= x
//结束行，x = startPage*pageSize
)
where rn >= y; //起始行，y = (startPage-1)*pageSize+1

1. 开发工程中异常处理注意：如果为MVC分层架构，不要在Service层中做异常处理，把异常抛到Controller进行处理。