一秒钟学会SprinvMvc开发

一、基础增删改查

1.1 环境搭建

1.1.1 导入相关的pom依赖

pom.xml

注意：如果本地仓库是第一次导入其包，那么我们首先导入properties标签里面的内容，然后导入dependencies的内容，在dependencies标签里面我们有几个依赖有顺序，首先要导入
org.springframework spring-webmvc ${spring.version}
然后导入
javax.servlet.jsp javax.servlet.jsp-api 2.3.3
在导入
jstl jstl 1.2
最后导入
taglibs standard 1.1.2
导入dependencies标签内容后我们在导入resources标签的内容，最后导入plugin内容即可

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>org.example</groupId>
  <artifactId>ssm02</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>ssm02 Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <maven.compiler.plugin.version>3.7.0</maven.compiler.plugin.version>

    <!--添加jar包依赖-->
    <!--1.spring 5.0.2.RELEASE相关-->
    <spring.version>5.0.2.RELEASE</spring.version>
    <!--2.mybatis相关-->
    <mybatis.version>3.4.5</mybatis.version>
    <!--mysql-->
    <mysql.version>5.1.44</mysql.version>
    <!--pagehelper分页jar依赖-->
    <pagehelper.version>5.1.2</pagehelper.version>
    <!--mybatis与spring集成jar依赖-->
    <mybatis.spring.version>1.3.1</mybatis.spring.version>
    <!--3.dbcp2连接池相关 druid-->
    <commons.dbcp2.version>2.1.1</commons.dbcp2.version>
    <commons.pool2.version>2.4.3</commons.pool2.version>
    <!--4.log日志相关-->
    <log4j2.version>2.9.1</log4j2.version>
    <!--5.其他-->
    <junit.version>4.12</junit.version>
    <servlet.version>4.0.0</servlet.version>
    <lombok.version>1.18.2</lombok.version>
  </properties>

  <dependencies>
    <!--1.spring相关-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-orm</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-tx</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aspects</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-test</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!--2.mybatis相关-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>${mybatis.version}</version>
    </dependency>
    <!--mysql-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>${mysql.version}</version>
    </dependency>
    <!--pagehelper分页插件jar包依赖-->
    <dependency>
      <groupId>com.github.pagehelper</groupId>
      <artifactId>pagehelper</artifactId>
      <version>${pagehelper.version}</version>
    </dependency>
    <!--mybatis与spring集成jar包依赖-->
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis-spring</artifactId>
      <version>${mybatis.spring.version}</version>
    </dependency>

    <!--3.dbcp2连接池相关-->
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-dbcp2</artifactId>
      <version>${commons.dbcp2.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.commons</groupId>
      <artifactId>commons-pool2</artifactId>
      <version>${commons.pool2.version}</version>
    </dependency>

    <!--4.log日志相关依赖-->
    <!--核心log4j2jar包-->
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-core</artifactId>
      <version>${log4j2.version}</version>
    </dependency>
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-api</artifactId>
      <version>${log4j2.version}</version>
    </dependency>
    <!--web工程需要包含log4j-web，非web工程不需要-->
    <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-web</artifactId>
      <version>${log4j2.version}</version>
    </dependency>

    <!--5.其他-->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>${junit.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>${servlet.version}</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
      <version>${lombok.version}</version>
      <scope>provided</scope>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!-- jsp依赖-->
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>javax.servlet.jsp-api</artifactId>
      <version>2.3.3</version>
    </dependency>

    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>

    <dependency>
      <groupId>taglibs</groupId>
      <artifactId>standard</artifactId>
      <version>1.1.2</version>
    </dependency>

  </dependencies>

  <build>
    <finalName>ssm02</finalName>
    <resources>
      <!--解决mybatis-generator-maven-plugin运行时没有将XxxMapper.xml文件放入target文件夹的问题-->
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.xml
        
      
      
      
        src/main/resources
        
          jdbc.properties
          *.xml
        
      
    

    
      

        
          org.apache.maven.plugins
          maven-compiler-plugin
          ${maven.compiler.plugin.version}
          
            ${maven.compiler.source}
            ${maven.compiler.target}
            ${project.build.sourceEncoding}
          
        
        
          org.mybatis.generator
          mybatis-generator-maven-plugin
          1.3.2
          
            
            
              mysql
              mysql-connector-java
              ${mysql.version}
            
          
          
            true
          
        

        
          maven-clean-plugin
          3.1.0
        
        
        
          maven-resources-plugin
          3.0.2
        
        
          maven-compiler-plugin
          3.8.0
        
        
          maven-surefire-plugin
          2.22.1
        
        
          maven-war-plugin
          3.2.2
        
        
          maven-install-plugin
          2.5.2
        
        
          maven-deploy-plugin
          2.8.2
        
      
    
  

1.1.2 导入相关配置文件

导入的配置文件有
applicationContext.xml
applicationContext-mybatis.xml
generatorConfig.xml
jdbc.properties
log4j2.xml
mybatis.cfg.xml
springmvc-servlet.xml
需要用到的分页工具类
PageTag.java
PageBean.java
StringUtils.java
标签tld文件
zking.tld
web.xml相关配置
web.xml

2.1 配置文件

applicationContext.xml

<?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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">

    <import resource="applicationContext-mybatis.xml"></import>

</beans>

applicationContext-mybatis.xml

<?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:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <!--1. 注解式开发 -->
    <!-- 注解驱动 -->
    <context:annotation-config/>
    <!-- 用注解方式注入bean，并指定查找范围：com.javaxl.ssm及子子孙孙包-->
    <context:component-scan base-package="com.xlb.ssm"/>

    <context:property-placeholder location="classpath:jdbc.properties"/>

    <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource"
          destroy-method="close">
        <property name="driverClassName" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <!--初始连接数-->
        <property name="initialSize" value="10"/>
        <!--最大活动连接数-->
        <property name="maxTotal" value="100"/>
        <!--最大空闲连接数-->
        <property name="maxIdle" value="50"/>
        <!--最小空闲连接数-->
        <property name="minIdle" value="10"/>
        <!--设置为-1时，如果没有可用连接，连接池会一直无限期等待，直到获取到连接为止。-->
        <!--如果设置为N（毫秒），则连接池会等待N毫秒，等待不到，则抛出异常-->
        <property name="maxWaitMillis" value="-1"/>
    </bean>

    <!--4. spring和MyBatis整合 -->
    <!--1) 创建sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <!-- 指定数据源 -->
        <property name="dataSource" ref="dataSource"/>
        <!-- 自动扫描XxxMapping.xml文件，**任意路径 -->
        <property name="mapperLocations" value="classpath*:com/xlb/ssm/**/mapper/*.xml"/>
        <!-- 指定别名 -->
        <property name="typeAliasesPackage" value="com/xlb/ssm/**/model"/>
        <!--配置pagehelper插件-->
        <property name="plugins">
            <array>
                <bean class="com.github.pagehelper.PageInterceptor">
                    <property name="properties">
                        <value>
                            helperDialect=mysql
                        </value>
                    </property>
                </bean>
            </array>
        </property>
    </bean>

    <!--2) 自动扫描com/javaxl/ssm/**/mapper下的所有XxxMapper接口(其实就是DAO接口)，并实现这些接口，-->
    <!--   即可直接在程序中使用dao接口，不用再获取sqlsession对象-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--basePackage 属性是映射器接口文件的包路径。-->
        <!--你可以使用分号或逗号 作为分隔符设置多于一个的包路径-->
        <property name="basePackage" value="com/xlb/ssm/**/mapper"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>

    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource" />
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager" />
    <aop:aspectj-autoproxy/>
</beans>

generatorConfig.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd" >
<generatorConfiguration>
    <!-- 引入配置文件 -->
    <properties resource="jdbc.properties"/>

    <!--指定数据库jdbc驱动jar包的位置-->
    <classPathEntry location="E:\\maven\\mavenjar\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/>

    <!-- 一个数据库一个context -->
    <context id="infoGuardian">
        <!-- 注释 -->
        <commentGenerator>
            <property name="suppressAllComments" value="true"/><!-- 是否取消注释 -->
            <property name="suppressDate" value="true"/> <!-- 是否生成注释代时间戳 -->
        </commentGenerator>

        <!-- jdbc连接 -->
        <jdbcConnection driverClass="${jdbc.driver}"
                        connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>

        <!-- 类型转换 -->
        <javaTypeResolver>
            <!-- 是否使用bigDecimal， false可自动转化以下类型（Long, Integer, Short, etc.） -->
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>

        <!-- 01 指定javaBean生成的位置 -->
        <!-- targetPackage：指定生成的model生成所在的包名 -->
        <!-- targetProject：指定在该项目下所在的路径  -->
        <javaModelGenerator targetPackage="com.xlb.ssm.model"
                            targetProject="src/main/java">
            <!-- 是否允许子包，即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
            <!-- 是否对model添加构造函数 -->
            <property name="constructorBased" value="true"/>
            <!-- 是否针对string类型的字段在set的时候进行trim调用 -->
            <property name="trimStrings" value="false"/>
            <!-- 建立的Model对象是否 不可改变  即生成的Model对象不会有 setter方法，只有构造方法 -->
            <property name="immutable" value="false"/>
        </javaModelGenerator>

        <!-- 02 指定sql映射文件生成的位置 -->
        <sqlMapGenerator targetPackage="com.xlb.ssm.mapper"
                         targetProject="src/main/java">
            <!-- 是否允许子包，即targetPackage.schemaName.tableName -->
            <property name="enableSubPackages" value="false"/>
        </sqlMapGenerator>

        <!-- 03 生成XxxMapper接口 -->
        <!-- type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象 -->
        <!-- type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象 -->
        <!-- type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口 -->
        <javaClientGenerator targetPackage="com.xlb.ssm.mapper"
                             targetProject="src/main/java" type="XMLMAPPER">
            <!-- 是否在当前路径下新加一层schema,false路径com.oop.eksp.user.model， true:com.oop.eksp.user.model.[schemaName] -->
            <property name="enableSubPackages" value="false"/>
        </javaClientGenerator>

        <!-- 配置表信息 -->
        <!-- schema即为数据库名 -->
        <!-- tableName为对应的数据库表 -->
        <!-- domainObjectName是要生成的实体类 -->
        <!-- enable*ByExample是否生成 example类 -->
        <!--<table schema="" tableName="t_book" domainObjectName="Book"-->
        <!--enableCountByExample="false" enableDeleteByExample="false"-->
        <!--enableSelectByExample="false" enableUpdateByExample="false">-->
        <!--&lt;!&ndash; 忽略列，不生成bean 字段 &ndash;&gt;-->
        <!--&lt;!&ndash; <ignoreColumn column="FRED" /> &ndash;&gt;-->
        <!--&lt;!&ndash; 指定列的java数据类型 &ndash;&gt;-->
        <!--&lt;!&ndash; <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /> &ndash;&gt;-->
        <!--</table>-->

        <table schema="" tableName="t_struts_class" domainObjectName="Clazz"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>





    </context>
</generatorConfiguration>

jdbc.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/y101?useUnicode=true&characterEncoding=UTF-8
jdbc.username=root
jdbc.password=123

log4j2.xml

<?xml version="1.0" encoding="UTF-8"?>

<!-- status : 指定log4j本身的打印日志的级别.ALL< Trace < DEBUG < INFO < WARN < ERROR 
	< FATAL < OFF。 monitorInterval : 用于指定log4j自动重新配置的监测间隔时间，单位是s,最小是5s. -->
<Configuration status="WARN" monitorInterval="30">
	<Properties>
		<!-- 配置日志文件输出目录 ${sys:user.home} -->
		<Property name="LOG_HOME">/root/workspace/lucenedemo/logs</Property>
		<property name="ERROR_LOG_FILE_NAME">/root/workspace/lucenedemo/logs/error</property>
		<property name="WARN_LOG_FILE_NAME">/root/workspace/lucenedemo/logs/warn</property>
		<property name="PATTERN">%d{yyyy-MM-dd HH:mm:ss.SSS} [%t-%L] %-5level %logger{36} - %msg%n</property>
	</Properties>

	<Appenders>
		<!--这个输出控制台的配置 -->
		<Console name="Console" target="SYSTEM_OUT">
			<!-- 控制台只输出level及以上级别的信息(onMatch),其他的直接拒绝(onMismatch) -->
			<ThresholdFilter level="trace" onMatch="ACCEPT"
				onMismatch="DENY" />
			<!-- 输出日志的格式 -->
			<!-- %d{yyyy-MM-dd HH:mm:ss, SSS} : 日志生产时间 %p : 日志输出格式 %c : logger的名称 
				%m : 日志内容，即 logger.info("message") %n : 换行符 %C : Java类名 %L : 日志输出所在行数 %M 
				: 日志输出所在方法名 hostName : 本地机器名 hostAddress : 本地ip地址 -->
			<PatternLayout pattern="${PATTERN}" />
		</Console>

		<!--文件会打印出所有信息，这个log每次运行程序会自动清空，由append属性决定，这个也挺有用的，适合临时测试用 -->
		<!--append为TRUE表示消息增加到指定文件中，false表示消息覆盖指定的文件内容，默认值是true -->
		<File name="log" fileName="logs/test.log" append="false">
			<PatternLayout
				pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
		</File>
		<!-- 这个会打印出所有的info及以下级别的信息，每次大小超过size， 则这size大小的日志会自动存入按年份-月份建立的文件夹下面并进行压缩，作为存档 -->
		<RollingFile name="RollingFileInfo" fileName="${LOG_HOME}/info.log"
			filePattern="${LOG_HOME}/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log">
			<!--控制台只输出level及以上级别的信息（onMatch），其他的直接拒绝（onMismatch） -->
			<ThresholdFilter level="info" onMatch="ACCEPT"
				onMismatch="DENY" />
			<PatternLayout
				pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
			<Policies>
				<!-- 基于时间的滚动策略，interval属性用来指定多久滚动一次，默认是1 hour。 modulate=true用来调整时间：比如现在是早上3am，interval是4，那么第一次滚动是在4am，接着是8am，12am...而不是7am. -->
				<!-- 关键点在于 filePattern后的日期格式，以及TimeBasedTriggeringPolicy的interval， 日期格式精确到哪一位，interval也精确到哪一个单位 -->
				<!-- log4j2的按天分日志文件 : info-%d{yyyy-MM-dd}-%i.log -->
				<TimeBasedTriggeringPolicy interval="1"
					modulate="true" />
				<!-- SizeBasedTriggeringPolicy:Policies子节点， 基于指定文件大小的滚动策略，size属性用来定义每个日志文件的大小. -->
				<!-- <SizeBasedTriggeringPolicy size="2 kB" /> -->
			</Policies>
		</RollingFile>

		<RollingFile name="RollingFileWarn" fileName="${WARN_LOG_FILE_NAME}/warn.log"
			filePattern="${WARN_LOG_FILE_NAME}/$${date:yyyy-MM}/warn-%d{yyyy-MM-dd}-%i.log">
			<ThresholdFilter level="warn" onMatch="ACCEPT"
				onMismatch="DENY" />
			<PatternLayout
				pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
			<Policies>
				<TimeBasedTriggeringPolicy />
				<SizeBasedTriggeringPolicy size="2 kB" />
			</Policies>
			<!-- DefaultRolloverStrategy属性如不设置，则默认为最多同一文件夹下7个文件，这里设置了20 -->
			<DefaultRolloverStrategy max="20" />
		</RollingFile>

		<RollingFile name="RollingFileError" fileName="${ERROR_LOG_FILE_NAME}/error.log"
			filePattern="${ERROR_LOG_FILE_NAME}/$${date:yyyy-MM}/error-%d{yyyy-MM-dd-HH-mm}-%i.log">
			<ThresholdFilter level="error" onMatch="ACCEPT"
				onMismatch="DENY" />
			<PatternLayout
				pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
			<Policies>
				<!-- log4j2的按分钟 分日志文件 : warn-%d{yyyy-MM-dd-HH-mm}-%i.log -->
				<TimeBasedTriggeringPolicy interval="1"
					modulate="true" />
				<!-- <SizeBasedTriggeringPolicy size="10 MB" /> -->
			</Policies>
		</RollingFile>

	</Appenders>

	<!--然后定义logger，只有定义了logger并引入的appender，appender才会生效 -->
	<Loggers>
		<!--过滤掉spring和mybatis的一些无用的DEBUG信息 -->
		<logger name="org.springframework" level="INFO"></logger>
		<logger name="org.mybatis" level="INFO"></logger>

		<!-- 第三方日志系统 -->
		<logger name="org.springframework" level="ERROR" />
		<logger name="org.hibernate" level="ERROR" />
		<logger name="org.apache.struts2" level="ERROR" />
		<logger name="com.opensymphony.xwork2" level="ERROR" />
		<logger name="org.jboss" level="ERROR" />


		<!-- 配置日志的根节点 -->
		<root level="all">
			<appender-ref ref="Console" />
			<appender-ref ref="RollingFileInfo" />
			<appender-ref ref="RollingFileWarn" />
			<appender-ref ref="RollingFileError" />
		</root>

	</Loggers>

</Configuration>

springmvc-servlet.xml这个配置文件要在WEB-INF目录下

springmvc-servlet.xml

<?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:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:aop="http://www.springframework.org/schema/aop"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
      http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd">
    <!-- 通过context:component-scan元素扫描指定包下的控制器-->
    <!--1) 扫描com.javaxl.zf及子子孙孙包下的控制器(扫描范围过大，耗时)-->
    <aop:aspectj-autoproxy/>
    <context:component-scan base-package="com.xlb.ssm"/>

    <!--2) 此标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter -->
    <!--两个bean，这两个bean是spring MVC为@Controllers分发请求所必须的。并提供了数据绑定支持，-->
    <!--@NumberFormatannotation支持，@DateTimeFormat支持，@Valid支持，读写XML的支持（JAXB），读写JSON的支持（Jackson）-->
    <mvc:annotation-driven></mvc:annotation-driven>

    <!--3) ViewResolver -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <!-- viewClass需要在pom中引入两个包：standard.jar and jstl.jar -->
        <property name="viewClass"
                  value="org.springframework.web.servlet.view.JstlView"></property>
        <property name="prefix" value="/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <!--4) 单独处理图片、样式、js等资源 -->
    <!--<mvc:resources location="/css/" mapping="/css/**"/>-->
    <!--<mvc:resources location="/images/" mapping="/images/**"/>-->
    <!--<mvc:resources location="/js/" mapping="/js/**"/>-->


</beans>

2.1.1 Web.xml配置

Web.xlm

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
         version="3.1">
  <display-name>Archetype Created Web Application</display-name>
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>
  <!-- 读取Spring上下文的监听器 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

  <!-- Spring MVC servlet -->
  <servlet>
    <servlet-name>SpringMVC</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--此参数可以不配置，默认值为：/WEB-INF/springmvc-servlet.xml-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/springmvc-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <!--web.xml 3.0的新特性，是否支持异步-->
    <async-supported>true</async-supported>
  </servlet>
  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

  <!-- 中文乱码处理 -->
  <filter>
    <filter-name>encodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <!--web.xml 3.0的新特性，是否支持异步-->
    <async-supported>true</async-supported>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>encodingFilter</filter-name>
    <url-pattern>/*
  

2.1.2 分页工具类

PageTag

package com.xlb.ssm.tag;

import com.xlb.ssm.util.PageBean;

import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;


public class PageTag extends BodyTagSupport{
	private PageBean pageBean;// 包含了所有分页相关的元素
	
	public PageBean getPageBean() {
		return pageBean;
	}

	public void setPageBean(PageBean pageBean) {
		this.pageBean = pageBean;
	}

	@Override
	public int doStartTag() throws JspException {
//		没有标签体，要输出内容
		JspWriter out = pageContext.getOut();
		try {
			out.print(toHTML());
		} catch (IOException e) {
			e.printStackTrace();
		}
		return super.doStartTag();
	}

	private String toHTML() {
		StringBuffer sb = new StringBuffer();
//		隐藏的form表单---这个就是上一次请求下次重新发的奥义所在
//		上一次请求的URL
		sb.append("
");
		sb.append("	");
//		上一次请求的参数
		Map<String, String[]> paramMap = pageBean.getParamMap();
		if(paramMap != null && paramMap.size() > 0) {
			Set<Entry<String, String[]>> entrySet = paramMap.entrySet();
			for (Entry<String, String[]> entry : entrySet) {
//				参数名
				String key = entry.getKey();
//				参数值
				for (String value : entry.getValue()) {
//					上一次请求的参数，再一次组装成了新的Form表单
//					注意：page参数每次都会提交，我们需要避免
					if(!"page".equals(key)) {
						sb.append("	");
					}
				}
			}
		}
		sb.append(""
);
		
//		分页条
		sb.append("
");
		sb.append("	
);
		sb.append("	href='javascript:gotoPage(1)'>首页
");
		sb.append("	
);
		sb.append("	href='javascript:gotoPage("+pageBean.previousPage()+")'><
");// less than 小于号
//		sb.append("	
1
");
//		sb.append("	
2
");
		sb.append("	
"+pageBean.getPage()+"
");
		sb.append("	
>
");
		sb.append("	
尾页
");
		sb.append("	
到第);
		sb.append("	type='text' id='skipPage' name='' />页
");
		sb.append("	
);
		sb.append("	href='javascript:skipPage()'>确定
");
		sb.append("	
共"+pageBean.getTotal()+"条
");
		sb.append("
");
		
//		分页执行的JS代码
		sb.append("");
		
		return sb.toString();
	}
}

PageBean

package com.xlb.ssm.util;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;

/**
 * 分页工具类
 *
 */
public class PageBean {

	private int page = 1;// 页码

	private int rows = 10;// 页大小

	private int total = 0;// 总记录数

	private boolean pagination = true;// 是否分页
	
	private String url; //保存上一次请求的URL
	
	private Map<String,String[]> paramMap = new HashMap<>();// 保存上一次请求的参数
	
	/**
	 * 初始化pagebean的，保存上一次请求的重要参数
	 * @param req
	 */
	public void setRequest(HttpServletRequest req) {
//		1.1	需要保存上一次请求的URL
		this.setUrl(req.getRequestURL().toString());
//		1.2	需要保存上一次请求的参数	bname、price
		this.setParamMap(req.getParameterMap());
//		1.3	需要保存上一次请求的分页设置	pagination
		this.setPagination(req.getParameter("pagination"));
//		1.4	需要保存上一次请求的展示条目数
		this.setRows(req.getParameter("rows"));
//		1.5  初始化请求的页码	page
		this.setPage(req.getParameter("page"));
	}
	
	public void setPage(String page) {
		if(StringUtils.isNotBlank(page))
			this.setPage(Integer.valueOf(page));
	}

	public void setRows(String rows) {
		if(StringUtils.isNotBlank(rows))
			this.setRows(Integer.valueOf(rows));
	}

	public void setPagination(String pagination) {
//		只有在前台jsp填写了pagination=false，才代表不分页
		if(StringUtils.isNotBlank(pagination))
			this.setPagination(!"false".equals(pagination));
	}


	public String getUrl() {
		return url;
	}

	public void setUrl(String url) {
		this.url = url;
	}

	public Map<String, String[]> getParamMap() {
		return paramMap;
	}

	public void setParamMap(Map<String, String[]> paramMap) {
		this.paramMap = paramMap;
	}



	public PageBean() {
		super();
	}

	public int getPage() {
		return page;
	}

	public void setPage(int page) {
		this.page = page;
	}

	public int getRows() {
		return rows;
	}

	public void setRows(int rows) {
		this.rows = rows;
	}

	public int getTotal() {
		return total;
	}

	public void setTotal(int total) {
		this.total = total;
	}

	public void setTotal(String total) {
		this.total = Integer.parseInt(total);
	}

	public boolean isPagination() {
		return pagination;
	}

	public void setPagination(boolean pagination) {
		this.pagination = pagination;
	}

	/**
	 * 获得起始记录的下标
	 * 
	 * @return
	 */
	public int getStartIndex() {
		return (this.page - 1) * this.rows;
	}
	
	/**
	 * 最大页
	 * @return
	 */
	public int maxPage() {
//		total % rows == 0 ? total / rows : total / rows +1
		return this.total % this.rows == 0 ? this.total / this.rows : this.total / this.rows + 1;
	}
	
	/**
	 * 下一页
	 * @return
	 */
	public int nextPage() {
//		如果当前页小于最大页，那就下一页为当前页+1；如果不小于，说明当前页就是最大页，那就无需+1
		return this.page < this.maxPage() ? this.page + 1 : this.page;
	}
	
	/**
	 * 上一页
	 * @return
	 */
	public int previousPage() {
		return this.page > 1 ? this.page - 1 : this.page;
	}

	@Override
	public String toString() {
		return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
	}

}

StringUtils

package com.xlb.ssm.util;

public class StringUtils {
	// 私有的构造方法，保护此类不能在外部实例化
	private StringUtils() {
	}

	/**
	 * 如果字符串等于null或去空格后等于""，则返回true，否则返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isBlank(String s) {
		boolean b = false;
		if (null == s || s.trim().equals("")) {
			b = true;
		}
		return b;
	}
	
	/**
	 * 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
	 * 
	 * @param s
	 * @return
	 */
	public static boolean isNotBlank(String s) {
		return !isBlank(s);
	}

}

2.1.3 tld文件

zking.tld

<?xml version="1.0" encoding="UTF-8" ?>

<taglib xmlns="http://java.sun.com/xml/ns/j2ee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"
    version="2.0">
    
  <description>zking 1.1 core library</description>
  <display-name>zking core</display-name>
  <tlib-version>1.1</tlib-version>
  <short-name>zking</short-name>
  <uri>http://jsp.veryedu.cn</uri>
  
  
  <tag>
    <name>page</name>
    <tag-class>com.xlb.ssm.tag.PageTag</tag-class>
    <body-content>JSP</body-content>
    <attribute>
        <name>pageBean</name>
        <required>true</required>
        <rtexprvalue>true</rtexprvalue>
    </attribute>
  </tag>
  
</taglib>

到这我们的配置环境就完成了

3.1 逆向生成

逆向生成我们要用到的表t_struts_class，这里要注意，我们取别名是首字母要大写，且不能是关键字比如Class等

<table schema="" tableName="t_struts_class" domainObjectName="Clazz"
               enableCountByExample="false" enableDeleteByExample="false"
               enableSelectByExample="false" enableUpdateByExample="false">
        </table>

那么就会有我们逆向生成的表和配置文件
ClazzMapper

这里我新增了一个分页的方法listPager

package com.xlb.ssm.mapper;

import com.xlb.ssm.model.Clazz;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface ClazzMapper {
    int deleteByPrimaryKey(Integer cid);

    int insert(Clazz record);

    int insertSelective(Clazz record);

    Clazz selectByPrimaryKey(Integer cid);

    List<Clazz> listPager(Clazz clazz);

    int updateByPrimaryKeySelective(Clazz record);

    int updateByPrimaryKey(Clazz record);
}

对应的配置文件ClazzMapper.xml

<?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="com.xlb.ssm.mapper.ClazzMapper" >
  <resultMap id="BaseResultMap" type="com.xlb.ssm.model.Clazz" >
    <constructor >
      <idArg column="cid" jdbcType="INTEGER" javaType="java.lang.Integer" />
      <arg column="cname" jdbcType="VARCHAR" javaType="java.lang.String" />
      <arg column="cteacher" jdbcType="VARCHAR" javaType="java.lang.String" />
      <arg column="pic" jdbcType="VARCHAR" javaType="java.lang.String" />
    </constructor>
  </resultMap>
  <sql id="Base_Column_List" >
    cid, cname, cteacher, pic
  </sql>


  <select id="listPager" resultType="com.xlb.ssm.model.Clazz" parameterType="com.xlb.ssm.model.Clazz" >
    select
    <include refid="Base_Column_List" />
    from t_struts_class
    <where>
        <if test="cname != null and cname !='' ">
            and cname like CONCAT('%',#{cname},'%')
        </if>

        <if test="cid != null and cname !='' ">
            and cid = #{cid}
        </if>
    </where>
  </select>


  <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Integer" >
    select 
    <include refid="Base_Column_List" />
    from t_struts_class
    where cid = #{cid,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer" >
    delete from t_struts_class
    where cid = #{cid,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.xlb.ssm.model.Clazz" >
    insert into t_struts_class (cid, cname, cteacher, 
      pic)
    values (#{cid,jdbcType=INTEGER}, #{cname,jdbcType=VARCHAR}, #{cteacher,jdbcType=VARCHAR}, 
      #{pic,jdbcType=VARCHAR})
  </insert>
  <insert id="insertSelective" parameterType="com.xlb.ssm.model.Clazz" >
    insert into t_struts_class
    <trim prefix="(" suffix=")" suffixOverrides="," >
      <if test="cid != null" >
        cid,
      </if>
      <if test="cname != null" >
        cname,
      </if>
      <if test="cteacher != null" >
        cteacher,
      </if>
      <if test="pic != null" >
        pic,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides="," >
      <if test="cid != null" >
        #{cid,jdbcType=INTEGER},
      </if>
      <if test="cname != null" >
        #{cname,jdbcType=VARCHAR},
      </if>
      <if test="cteacher != null" >
        #{cteacher,jdbcType=VARCHAR},
      </if>
      <if test="pic != null" >
        #{pic,jdbcType=VARCHAR},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.xlb.ssm.model.Clazz" >
    update t_struts_class
    <set >
      <if test="cname != null" >
        cname = #{cname,jdbcType=VARCHAR},
      </if>
      <if test="cteacher != null" >
        cteacher = #{cteacher,jdbcType=VARCHAR},
      </if>
      <if test="pic != null" >
        pic = #{pic,jdbcType=VARCHAR},
      </if>
    </set>
    where cid = #{cid,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.xlb.ssm.model.Clazz" >
    update t_struts_class
    set cname = #{cname,jdbcType=VARCHAR},
      cteacher = #{cteacher,jdbcType=VARCHAR},
      pic = #{pic,jdbcType=VARCHAR}
    where cid = #{cid,jdbcType=INTEGER}
  </update>
</mapper>

Biz层ClazzBiz

package com.xlb.ssm.biz;

import com.xlb.ssm.model.Clazz;
import com.xlb.ssm.util.PageBean;
import org.springframework.web.bind.annotation.RequestMapping;

import java.util.List;

public interface ClazzBiz {
    int deleteByPrimaryKey(Integer cid);

    int insert(Clazz record);

    int insertSelective(Clazz record);

    Clazz selectByPrimaryKey(Integer cid);

    int updateByPrimaryKeySelective(Clazz record);

    int updateByPrimaryKey(Clazz record);

    List<Clazz> listPager(Clazz clazz, PageBean pageBean);
}

实现层ClazzBizImpl

package com.xlb.ssm.biz.impl;

import com.xlb.ssm.biz.ClazzBiz;
import com.xlb.ssm.mapper.ClazzMapper;
import com.xlb.ssm.model.Clazz;
import com.xlb.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

/**
 * @author 波哥
 * @QQ 2212371722
 * @company 波哥集团
 * @create  2022-08-17 20:42
 */

@Service
public class ClazzBizImpl implements ClazzBiz {

    @Autowired
    private ClazzMapper clazzMapper;

    @Override
    public int deleteByPrimaryKey(Integer cid) {
        return clazzMapper.deleteByPrimaryKey(cid);
    }

    @Override
    public int insert(Clazz record) {
        return clazzMapper.insert(record);
    }

    @Override
    public int insertSelective(Clazz record) {
        return clazzMapper.insertSelective(record);
    }

    @Override
    public Clazz selectByPrimaryKey(Integer cid) {
        return clazzMapper.selectByPrimaryKey(cid);
    }

    @Override
    public int updateByPrimaryKeySelective(Clazz record) {
        return clazzMapper.updateByPrimaryKeySelective(record);
    }

    @Override
    public int updateByPrimaryKey(Clazz record) {
        return clazzMapper.updateByPrimaryKey(record);
    }

    @Override
    public List<Clazz> listPager(Clazz clazz, PageBean pageBean) {
        return clazzMapper.listPager(clazz);
    }
}

4.1 代码开发

4.1.1 web层

ClazzController

package com.xlb.ssm.controller;

import com.xlb.ssm.biz.ClazzBiz;
import com.xlb.ssm.model.Clazz;
import com.xlb.ssm.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.http.HttpServletRequest;
import java.util.List;

/**
 * @author 波哥
 * @QQ 2212371722
 * @company 波哥集团
 * @create  2022-08-17 20:54
 */

@Controller
@RequestMapping("/clz")
public class ClazzController {

    @Autowired
    private ClazzBiz clazzBiz;

    @RequestMapping("/list")
    public String list(Clazz clazz, HttpServletRequest request){
        PageBean pageBean = new PageBean();
        pageBean.setRequest(request);
        List<Clazz> clazzes = this.clazzBiz.listPager(clazz, pageBean);
        request.setAttribute("lst",clazzes);
        request.setAttribute("pageBean",pageBean);
        return "clzList";
    }

    @RequestMapping("/toEdit")
    public String toEdit(Clazz clazz, HttpServletRequest request){
        Integer cid = clazz.getCid();
        //传递的id代表是修改还是新增
        if(cid != null){
            List<Clazz> clazzes = this.clazzBiz.listPager(clazz, null);
            request.setAttribute("b",clazzes.get(0));
        }
        return "clzEdit";
    }

    @RequestMapping("/add")
    public String add(Clazz clazz){
        this.clazzBiz.insertSelective(clazz);
        return "redirect:/clz/list";
    }

    @RequestMapping("/edit")
    public String edit(Clazz clazz){
        this.clazzBiz.updateByPrimaryKeySelective(clazz);
        return "redirect:/clz/list";
    }

    @RequestMapping("/del")
    public String del(Clazz clazz){
        this.clazzBiz.deleteByPrimaryKey(clazz.getCid());
        return "redirect:/clz/list";
    }

}

4.1.2 页面层

clzList.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<%@ taglib uri="http://jsp.veryedu.cn" prefix="z"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <link
            href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css"
            rel="stylesheet">
    <script
            src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.js"></script>
    <title>博客列表</title>
    <style type="text/css">
        .page-item input {
            padding: 0;
            width: 40px;
            height: 100%;
            text-align: center;
            margin: 0 6px;
        }

        .page-item input, .page-item b {
            line-height: 38px;
            float: left;
            font-weight: 400;
        }

        .page-item.go-input {
            margin: 0 10px;
        }
    </style>
</head>
<body>
<form class="form-inline"
      action="${pageContext.request.contextPath }/clz/list" method="post">
    <div class="form-group mb-2">
        <input type="text" class="form-control-plaintext" name="cname"
               placeholder="请输入班级名称">
    </div>
    <button type="submit" class="btn btn-primary mb-2">查询</button>
    <a class="btn btn-primary mb-2" href="${pageContext.request.contextPath }/clz/toEdit">新增</a>
</form>

<table class="table table-striped bg-success">
    <thead>
    <tr>
        <th scope="col">ID</th>
        <th scope="col">班级名称</th>
        <th scope="col">指导老师</th>
        <th scope="col">班级相册</th>
        <th scope="col">操作</th>
    </tr>
    </thead>
    <tbody>
    <c:forEach  var="b" items="${lst }">
        <tr>
            <td>${b.cid }</td>
            <td>${b.cname }</td>
            <td>${b.cteacher }</td>
            <td>${b.pic }</td>
            <td>
                <a href="${pageContext.request.contextPath }/clz/toEdit?cid=${b.cid}">修改</a>
                <a href="${pageContext.request.contextPath }/clz/del?cid=${b.cid}">删除</a>
            </td>
        </tr>
    </c:forEach>
    </tbody>
</table>
<!-- 这一行代码就相当于前面分页需求前端的几十行了 -->
<z:page pageBean="${pageBean }"></z:page>

</body>
</html>

clzEdit.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <title>博客的编辑界面</title>
</head>
<body>
<form action="${pageContext.request.contextPath }/clz/${empty b ? 'add' : 'edit'}" method="post">
    cid:<input type="text" name="cid" value="${b.cid }"><br>
    cname:<input type="text" name="cname" value="${b.cname }"><br>
    cteacher:<input type="text" name="cteacher" value="${b.cteacher }"><br>
    <input type="submit">
</form>
</body>
</html>

5.1 测试

5.1.1 分页查询

5.1.2 增加

5.1.3 修改

5.1.4 删除

删除id为12的学生

二、文件上传

步骤

1. Springmvc.xml中添加 多功能解析器 配置
2. 前台页面 添加 多功能表单设置 mutipart/form-data
3. 后台要利用multipartFile类进行 文件接收
   multipartFile的属性名一定要跟from表单属性名一致
4. 在IDER中完成图片请求地址与硬盘的映射关系

2.1 第一步（可有可无）：导入pom.xml依赖

<dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.3</version>
</dependency>

2.2 第二步：Springmvc.xml中添加 多功能解析器 配置

 <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 必须和用户JSP 的pageEncoding属性一致，以便正确解析表单的内容 -->
        <property name="defaultEncoding" value="UTF-8"></property>
        <!-- 文件最大大小(字节) 1024*1024*50=50M-->
        <property name="maxUploadSize" value="52428800"></property>
        <!--resolveLazily属性启用是为了推迟文件解析，以便捕获文件大小异常-->
        <property name="resolveLazily" value="true"/>
    </bean>

2.3 第三步：写前端界面clzupload.jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2022/8/18
  Time: 17:40
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%--enctype="multipart/form-data"多功能表单--%>
<form action="${pageContext.request.contextPath}/clz/upload" method="post" enctype="multipart/form-data">
    <%--为了方便所有把id展示--%>
    <input type="text" value="${param.cid}" name="cid">
    <input type="file" name="picFile">
    <input type="submit">
</form>
</body>
</html>

2.4 第四步：编写Dto类

Dto：接受参数，参数不仅仅存在与实体类Model中
protected会被子类继承

首先我们要修改实体类要其属性那够被子类继承

package com.xlb.ssm.model;

public class Clazz {
    //protected会被子类继承
    protected Integer cid;

    protected String cname;

    protected String cteacher;

    protected String pic;

    public Clazz(Integer cid, String cname, String cteacher, String pic) {
        this.cid = cid;
        this.cname = cname;
        this.cteacher = cteacher;
        this.pic = pic;
    }

    public Clazz() {
        super();
    }

    public Integer getCid() {
        return cid;
    }

    public void setCid(Integer cid) {
        this.cid = cid;
    }

    public String getCname() {
        return cname;
    }

    public void setCname(String cname) {
        this.cname = cname;
    }

    public String getCteacher() {
        return cteacher;
    }

    public void setCteacher(String cteacher) {
        this.cteacher = cteacher;
    }

    public String getPic() {
        return pic;
    }

    public void setPic(String pic) {
        this.pic = pic;
    }
}

然后编写ClazzDto

package com.xlb.ssm.model.dto;

import com.xlb.ssm.model.Clazz;
import org.springframework.web.multipart.MultipartFile;

/**
 * @author 波哥
 * @QQ 2212371722
 * @company 波哥集团
 * @create  2022-08-18 17:47
 */
public class ClazzDto extends Clazz {
    private MultipartFile picFile;

    public MultipartFile getPicFile() {
        return picFile;
    }

    public void setPicFile(MultipartFile picFile) {
        this.picFile = picFile;
    }
}

2.5 第五部：编写web层

这里有两种方法
第一种没有导入
commons-fileupload commons-fileupload 1.3.3

/*文件上传*/
    @RequestMapping("/upload")
    public String upload(ClazzDto clazzDto){
        try {
            //前台上传到后台的文件
            MultipartFile picFile = clazzDto.getPicFile();
            //实际应该配置到resource.properties中
            //图片存放地址
            String disPatch = "E:/222/";
            //数据库保存地址 也是 访问地址
            String requestPath = "/upload/mvc/";

            InputStream inputStream = picFile.getInputStream();

            //拿到上传文件的名字
            String Filename = picFile.getOriginalFilename();

            //FileUtils.copyInputStreamToFile(picFile.getInputStream(),new File(disPatch+Filename));

            //将图片上传之后 ， 并且将图片地址更新到数据库中
            FileOutputStream fileOutputStream = new FileOutputStream(new File("d/temp/1.png"));
            byte[] buff = new byte[1024];
            int len = 0;
            while (true){
                len = inputStream.read(buff,0,len);
                fileOutputStream.write(buff,0,len);
                if(len<0){
                    break;
                }
            }
            Clazz clazz = new Clazz();
            clazz.setCid(clazzDto.getCid());
            clazz.setPic(requestPath+Filename);

            this.clazzBiz.updateByPrimaryKeySelective(clazz);

        }catch (Exception e){
            e.printStackTrace();
        }
        return "redirect:/clz/list";
    }

导入pom依赖

 @RequestMapping("/upload")
    public String upload(ClazzDto clazzDto){
        try {
            //前台上传到后台的文件
            MultipartFile picFile = clazzDto.getPicFile();
            //实际应该配置到resource.properties中
            //图片存放地址
            String disPatch = "E:/222";
            //数据库保存地址 也是 访问地址
            String requestPath = "/upload/mvc/";

            //拿到上传文件的名字
            String Filename = picFile.getOriginalFilename();

            FileUtils.copyInputStreamToFile(picFile.getInputStream(),new File(disPatch+Filename));

            //将图片上传之后 ， 并且将图片地址更新到数据库中
            Clazz clazz = new Clazz();
            clazz.setCid(clazzDto.getCid());
            clazz.setPic(requestPath+Filename);

            this.clazzBiz.updateByPrimaryKeySelective(clazz);
        }catch (Exception e){
            e.printStackTrace();
        }
        return "redirect:/clz/list";
    }

2.6 ider与本地硬盘图片映射

选择自己图片映射地址

所以我们把网络请求地址改为我们项目请求地址

点击Ok即可

2.7 主界面编写

<%@ page language="java" contentType="text/html; charset=UTF-8"
         pageEncoding="UTF-8"%>
<%@ taglib uri="http://jsp.veryedu.cn" prefix="z"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <link
            href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css"
            rel="stylesheet">
    <script
            src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.js"></script>
    <title>博客列表</title>
    <style type="text/css">
        .page-item input {
            padding: 0;
            width: 40px;
            height: 100%;
            text-align: center;
            margin: 0 6px;
        }

        .page-item input, .page-item b {
            line-height: 38px;
            float: left;
            font-weight: 400;
        }

        .page-item.go-input {
            margin: 0 10px;
        }
    </style>
</head>
<body>
<form class="form-inline"
      action="${pageContext.request.contextPath }/clz/list" method="post">
    <div class="form-group mb-2">
        <input type="text" class="form-control-plaintext" name="cname"
               placeholder="请输入班级名称">
    </div>
    <button type="submit" class="btn btn-primary mb-2">查询</button>
    <a class="btn btn-primary mb-2" href="${pageContext.request.contextPath }/clz/toEdit">新增</a>
</form>

<table class="table table-striped bg-success">
    <thead>
    <tr>
        <th scope="col">ID</th>
        <th scope="col">班级名称</th>
        <th scope="col">指导老师</th>
        <th scope="col">班级相册</th>
        <th scope="col">操作</th>
    </tr>
    </thead>
    <tbody>
    <c:forEach  var="b" items="${lst }">
        <tr>
            <td>${b.cid }</td>
            <td>${b.cname }</td>
            <td>${b.cteacher }</td>
            <td>
                <img src="${pageContext.request.contextPath }${b.pic }" style="height: 100px;width: 100px">
            </td>
            <td>
                <a href="${pageContext.request.contextPath }/clz/toEdit?cid=${b.cid}">修改</a>
                <a href="${pageContext.request.contextPath }/clz/del?cid=${b.cid}">删除</a>
                <a href="${pageContext.request.contextPath }/clz/upload?cid=${b.cid}">上传图片</a>
            </td>
        </tr>
    </c:forEach>
    </tbody>
</table>
<!-- 这一行代码就相当于前面分页需求前端的几十行了 -->
<z:page pageBean="${pageBean }"></z:page>

</body>
</html>

2.8 测试

三、文件下载

1.点击下载传递文件的id，通过文件的ID查询出文件的路径
2.通过文件的请求地址，转换成文件的硬盘地址
3.将硬盘中的文件下载下来

在主界面添加操作

<a href="${pageContext.request.contextPath }/download?cid=${b.cid}">下载图片</a>

编写web层，写download

  /*文件下载*/
    @RequestMapping("/download")
    public ResponseEntity download(ClazzDto clazzDto){
        try {
            //1.点击下载传递文件的id，通过文件的ID查询出文件的路径
            Clazz clazz = this.clazzBiz.selectByPrimaryKey(clazzDto.getCid());
            String pic = clazz.getPic();
            //实际应该配置到resource.properties中
            //图片存放地址
            String disPatch = "E:/222/";
            //数据库保存地址 也是 访问地址
            String requestPath = "/upload/mvc/";

            //2.通过文件的请求地址，转换成文件的硬盘地址
            String realPath = pic.replace(requestPath,disPatch);
            //可能图片地址是中文，所以分割后缀
            String fileName = realPath.substring(realPath.lastIndexOf("/")+1);


            File file=new File(realPath);
            HttpHeaders headers = new HttpHeaders();//http头信息
            String downloadFileName = new String(fileName.getBytes("UTF-8"),"iso-8859-1");//设置编码
            headers.setContentDispositionFormData("attachment", downloadFileName);
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
            //MediaType:互联网媒介类型  contentType：具体请求中的媒体类型信息
            return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK);

        }catch (Exception e){
            e.printStackTrace();
        }
        return null;
    }

测试