【MyBatis】spring整合mybatis教程（详细易懂）

港控/mmm° 2024-03-24 21:24 93阅读 0赞

**目录**

一、引言

1、Spring整合MyBatis的目的是？

二、Spring与MyBatis集成

1、导入pom依赖及插件

1.1、导入依赖

1.2、导入插件

2、配置文件

generatorConfig.xml

jdbc.properties

log4j2.xml

spring-mybatis.xml

spring-context.xml

生成model、mapper

3、整合测试

1、建立Bookbiz、BookBizImpl

2、创建测试类

3、实体类的更改

三、Spring Aop集成PageHelper插件

1、回顾之前

2、优化

--------------------

## 一、引言 ##

### 1、Spring整合MyBatis的目的是？ ###

> **将两个框架结合起来，以实现更好的开发体验和效果。Spring提供了一种轻量级的容器和依赖注入的机制，可以简化应用程序的配置和管理。而MyBatis是一个优秀的持久层框架，可以方便地进行数据库操作。通过整合Spring和MyBatis，可以充分发挥它们各自的优势，提高开发效率和代码质量。**

## 二、Spring与MyBatis集成 ##

> **【注意！！！】整合的时候我们要导入我们的依赖、配置文件及测试是否整合成功**
> 
> 1.  **pom依赖：**spring、mybatis、logger、mysql、mybatis-spring、.....、junit、spring-test
> 2.  **配置文件：**spring-context.xml、spring-mybatis.xml、jdbc.properties、generateConfig.xml、log4j.xml
> 3.  **测试：**
>     
>     1.  根据表生成对应的实体类、mapper接口、mapper文件。
>     2.  测试类标记为spring测试类，会用**注解标记**，就代表每一个测试方法，都会加载spring的上下文

### 1、导入pom依赖及插件 ###

#### 1.1、导入依赖 ####

<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>
    
        
        
        <spring.version>5.0.2.RELEASE</spring.version>
        
        <mybatis.version>3.4.5</mybatis.version>
        
        <mysql.version>5.1.44</mysql.version>
        
        <pagehelper.version>5.1.2</pagehelper.version>
        
        <mybatis.spring.version>1.3.1</mybatis.spring.version>
        
        <commons.dbcp2.version>2.1.1</commons.dbcp2.version>
        <commons.pool2.version>2.4.3</commons.pool2.version>
        
        <log4j2.version>2.9.1</log4j2.version>
        
        <junit.version>4.12</junit.version>
        <servlet.version>4.0.0</servlet.version>
        <lombok.version>1.18.2</lombok.version>
    </properties>
    
    
    <dependencies>
        
        <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>
    
        
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>${mysql.version}</version>
        </dependency>
        
        <dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper</artifactId>
            <version>${pagehelper.version}</version>
        </dependency>
        
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>${mybatis.spring.version}</version>
        </dependency>
    
        
        <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>
    
        
        
        <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>
        
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-web</artifactId>
            <version>${log4j2.version}</version>
        </dependency>
    
        
        <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>
    
    </dependencies>

> **①数据库连接池是什么？**
> 
> 会初始化N个数据库链接对象，一般在10个，当需要用户请求操作数据库时候，那么就会直接在数据库连接池中获取链接，用完放回连接池中。
> 
> 常见的数据库连接池有：**dbcp2**、**druid**、**c3p0**.
> 
> **②lombok是什么？**
> 
> 可以更加便捷的使用实体类

<resources>
        
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.xml</include>
            </includes>
        </resource>
        
        <resource>
            <directory>src/main/resources</directory>
            <includes>
                <include>jdbc.properties</include>
                <include>*.xml</include>
            </includes>
        </resource>
    </resources>

#### 1.2、导入插件 ####

<plugins>
                <plugin>
                    <groupId>org.apache.maven.plugins</groupId>
                    <artifactId>maven-compiler-plugin</artifactId>
                    <version>${maven.compiler.plugin.version}</version>
                    <configuration>
                        <source>${maven.compiler.source}</source>
                        <target>${maven.compiler.target}</target>
                        <encoding>${project.build.sourceEncoding}</encoding>
                    </configuration>
                </plugin>
                <plugin>
                    <groupId>org.mybatis.generator</groupId>
                    <artifactId>mybatis-generator-maven-plugin</artifactId>
                    <version>1.3.2</version>
                    <dependencies>
                        
                        <dependency>
                            <groupId>mysql</groupId>
                            <artifactId>mysql-connector-java</artifactId>
                            <version>${mysql.version}</version>
                        </dependency>
                    </dependencies>
                    <configuration>
                        <overwrite>true</overwrite>
                    </configuration>
                </plugin>
            </plugins>

### 2、配置文件 ###

#### 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>
>         
>         <properties resource="jdbc.properties"/>
>     
>         
>         <classPathEntry
>                 location="D:\\zking App\\mvn_repository\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/>
>     
>         
>         <context id="infoGuardian">
>             
>             <commentGenerator>
>                 <property name="suppressAllComments" value="true"/>
>                 <property name="suppressDate" value="true"/> 
>             </commentGenerator>
>     
>             
>             <jdbcConnection driverClass="${jdbc.driver}"
>                             connectionURL="${jdbc.url}" userId="${jdbc.username}" password="${jdbc.password}"/>
>     
>             
>             <javaTypeResolver>
>                 
>                 <property name="forceBigDecimals" value="false"/>
>             </javaTypeResolver>
>     
>             
>             
>             
>             <javaModelGenerator targetProject="src/main/java" targetPackage="com.tgq.model">
>                 
>                 <property name="enableSubPackages" value="false"/>
>                 
>                 <property name="constructorBased" value="true"/>
>                 
>                 <property name="trimStrings" value="false"/>
>                 
>                 <property name="immutable" value="false"/>
>             </javaModelGenerator>
>     
>             
>             <sqlMapGenerator targetProject="src/main/java" targetPackage="com.tgq.mapper">
>                 
>                 <property name="enableSubPackages" value="false"/>
>             </sqlMapGenerator>
>     
>             
>             
>             
>             
>             <javaClientGenerator targetProject="src/main/java" targetPackage="com.tgq.mapper" type="XMLMAPPER">
>                 
>                 <property name="enableSubPackages" value="false"/>
>             </javaClientGenerator>
>     
>             
>             
>             
>             
>             
>             
>             
>             
>             
>             
>             
>             
>             
>     
>             <table schema="" tableName="t_mvc_Book" domainObjectName="Book"
>                    enableCountByExample="false" enableDeleteByExample="false"
>                    enableSelectByExample="false" enableUpdateByExample="false">
>                 
>                 
>                 
>                 
>             </table>
>     
>         </context>
>     </generatorConfiguration>
> 
> 这里是自己本地路径的MySQL的jar包，是需要更改的，路径赋值后也需要再加上**\\**
> 
>     
>         <classPathEntry
>                 location="D:\\zking App\\mvn_repository\\mysql\\mysql-connector-java\\5.1.44\\mysql-connector-java-5.1.44.jar"/>

#### jdbc.properties ####

> **数据库的连接对象**
> 
>     jdbc.driver=com.mysql.jdbc.Driver
>     jdbc.url=jdbc:mysql://localhost:3306/mybatis_ssm?useUnicode=true&characterEncoding=UTF-8
>     jdbc.username=root
>     jdbc.password=123456
> 
> ![aaf7fc5902a0475aad7df47f9d9c101a.png][]

#### log4j2.xml ####

<?xml version="1.0" encoding="UTF-8"?>
    
    
    <Configuration status="WARN" monitorInterval="30">
        <Properties>
            
            <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>
            
            <Console name="Console" target="SYSTEM_OUT">
                
                <ThresholdFilter level="trace" onMatch="ACCEPT"
                                 onMismatch="DENY" />
                
                
                <PatternLayout pattern="${PATTERN}" />
            </Console>
    
            
            
            <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>
            
            <RollingFile name="RollingFileInfo" fileName="${LOG_HOME}/info.log"
                         filePattern="${LOG_HOME}/$${date:yyyy-MM}/info-%d{yyyy-MM-dd}-%i.log">
                
                <ThresholdFilter level="info" onMatch="ACCEPT"
                                 onMismatch="DENY" />
                <PatternLayout
                        pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />
                <Policies>
                    
                    
                    
                    <TimeBasedTriggeringPolicy interval="1"
                                               modulate="true" />
                    
                    
                </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 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>
                    
                    <TimeBasedTriggeringPolicy interval="1"
                                               modulate="true" />
                    
                </Policies>
            </RollingFile>
    
        </Appenders>
    
        
        <Loggers>
            
            <logger name="org.springframework" level="INFO"></logger>
            <logger name="org.mybatis" level="INFO"></logger>
    
            
            <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" />
    
    
            
            <root level="all">
                <appender-ref ref="Console" />
                <appender-ref ref="RollingFileInfo" />
                <appender-ref ref="RollingFileWarn" />
                <appender-ref ref="RollingFileError" />
            </root>
    
        </Loggers>
    
    </Configuration>

#### spring-mybatis.xml ####

1.  扫描所有JavaBean，将对应的组件加载到spring的上下文
2.  配置session连接工厂
3.  配置mapper扫描接口
4.  配置事务管理器
5.  配置aop自动代理

>     <?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">
>         
>         
>         <context:annotation-config/>
>         
>         <context:component-scan base-package="com.tgq"/>
>     
>         <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}"/>
>             
>             <property name="initialSize" value="10"/>
>             
>             <property name="maxTotal" value="100"/>
>             
>             <property name="maxIdle" value="50"/>
>             
>             <property name="minIdle" value="10"/>
>             
>             
>             <property name="maxWaitMillis" value="-1"/>
>         </bean>
>     
>         
>         
>         <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
>             
>             <property name="dataSource" ref="dataSource"/>
>             
>             <property name="mapperLocations" value="classpath*:com/tgq/**/mapper/*.xml"/>
>             
>             <property name="typeAliasesPackage" value="com/javaxl/ssm/**/model"/>
>             
>             <property name="plugins">
>                 <array>
>                     <bean class="com.github.pagehelper.PageInterceptor">
>                         <property name="properties">
>                             <value>
>                                 helperDialect=mysql
>                             </value>
>                         </property>
>                     </bean>
>                 </array>
>             </property>
>         </bean>
>     
>         
>         
>         <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
>             
>             
>             <property name="basePackage" value="com/tgq/**/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>

> **注意自己的包名路径，如果不更改后面测试会报错**  
> ![be3b4f6f83ef4d31aa46d27d41d06e7b.png][]  
>   
> ![a671fa880b8844718e54aa3fd21f9240.png][]

#### spring-context.xml ####

#### 生成model、mapper ####

选中对应的项目，依次选中生成

![643aa26457964bb1a27e06e93e565b42.png][]

![23374ad8a62544ef9d8358606bbc8e9a.png][]

> 我们在生成的实体类上面添加**@Repository**，**@Repository**就相当于**<bean id="BookMapper" class="com.tgq.mapper.BookMapper"/>**

![2e8b4b91c299426c8cfa30f61d8119eb.png][]

### 3、整合测试 ###

> #### 1、建立**Bookbiz**、**BookBizImpl** ####
> 
> 一个接口和一个接口实现类
> 
> ![111799a32d3b4a529921b4aca51f5d9a.png][]
> 
> 把我们的生成的BookMapper里面的方法复制到我们新建的BookBiz里面
> 
> ![d0af56a85fe14041a3dca38fb1581389.png][]
> 
> ![0a82c17f899947528a9ef1a101cd4b91.png][]
> 
>     package com.tgq.biz;
>     
>     import com.tgq.model.Book;
>     
>     /**
>      * @软件包名 com.tgq.biz
>      * @用户 tgq
>      * @create 2023-08-25 下午4:46
>      * @注释说明：
>      */
>     public interface BookBiz {
>         int deleteByPrimaryKey(Integer bid);
>     
>         int insert(Book record);
>     
>         int insertSelective(Book record);
>     
>         Book selectByPrimaryKey(Integer bid);
>     
>         int updateByPrimaryKeySelective(Book record);
>     
>         int updateByPrimaryKey(Book record);
>     }
> 
>     package com.tgq.biz.impl;
>     
>     import com.tgq.biz.BookBiz;
>     import com.tgq.mapper.BookMapper;
>     import com.tgq.model.Book;
>     import org.springframework.beans.factory.annotation.Autowired;
>     import org.springframework.stereotype.Service;
>     
>     /**
>      * @软件包名 com.tgq.biz.impl
>      * @用户 tgq
>      * @create 2023-08-25 下午4:49
>      * @注释说明：
>      */
>     @Service//仓库的意思
>     public class BookBizImpl implements BookBiz {
>     
>         @Autowired//相当于get、set
>         private BookMapper bookBiz;
>     
>         @Override
>         public int deleteByPrimaryKey(Integer bid) {
>             return bookBiz.deleteByPrimaryKey(bid);
>         }
>     
>         @Override
>         public int insert(Book record) {
>             return bookBiz.insert(record);
>         }
>     
>         @Override
>         public int insertSelective(Book record) {
>             return bookBiz.insertSelective(record);
>         }
>     
>         @Override
>         public Book selectByPrimaryKey(Integer bid) {
>             return bookBiz.selectByPrimaryKey(bid);
>         }
>     
>         @Override
>         public int updateByPrimaryKeySelective(Book record) {
>             return bookBiz.updateByPrimaryKeySelective(record);
>         }
>     
>         @Override
>         public int updateByPrimaryKey(Book record) {
>             return bookBiz.updateByPrimaryKey(record);
>         }
>     }

#### 2、创建测试类 ####

> 创建**BookBizImpl**测试类
> 
> ![7b3d3b222a5e4125851b5e9e9e238452.png][]
> 
> 我们调用一个测试方法进行测试
> 
>     package com.tgq.biz.impl;
>     
>     import com.tgq.biz.BookBiz;
>     import org.junit.After;
>     import org.junit.Before;
>     import org.junit.Test;
>     import org.junit.runner.RunWith;
>     import org.springframework.beans.factory.annotation.Autowired;
>     import org.springframework.test.context.ContextConfiguration;
>     import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
>     
>     /**
>      * @软件包名 com.tgq.biz.impl
>      * @用户 tgq
>      * @create 2023-08-25 下午4:56
>      * @注释说明：
>      */
>     @RunWith(SpringJUnit4ClassRunner.class)
>     @ContextConfiguration(locations = {"classpath:spring-context.xml"})
>     public class BookBizImplTest {
>     
>         @Autowired//相当于get、set
>         private BookBiz bookBiz;
>     
>         @Before
>         public void setUp() throws Exception {
>         }
>     
>         @After
>         public void tearDown() throws Exception {
>         }
>     
>         @Test
>         public void deleteByPrimaryKey() {
>         }
>     
>         @Test
>         public void insert() {
>         }
>     
>         @Test
>         public void insertSelective() {
>         }
>     
>         @Test
>         public void selectByPrimaryKey() {
>             System.out.println(this.bookBiz.selectByPrimaryKey(60));
>         }
>     
>         @Test
>         public void updateByPrimaryKeySelective() {
>         }
>     
>         @Test
>         public void updateByPrimaryKey() {
>         }
>     }
> 
> 测试结果![3454c747084147f3b6d50c1a2a9fa51c.png][]
> 
>   
>

#### 3、实体类的更改 ####

> 我们的实体类创建属性的时候我写get、set等方法，过于麻烦，但是我们有一个lombok，可以节约掉这些。
> 
> **1、没有lombok的实体类** 
> 
>     package com.tgq.model;
>     
>     public class Book {
>         private Integer bid;
>     
>         private String bname;
>     
>         private Float price;
>     
>         public Book(Integer bid, String bname, Float price) {
>             this.bid = bid;
>             this.bname = bname;
>             this.price = price;
>         }
>     
>         public Book() {
>             super();
>         }
>     
>         public Integer getBid() {
>             return bid;
>         }
>     
>         public void setBid(Integer bid) {
>             this.bid = bid;
>         }
>     
>         public String getBname() {
>             return bname;
>         }
>     
>         public void setBname(String bname) {
>             this.bname = bname;
>         }
>     
>         public Float getPrice() {
>             return price;
>         }
>     
>         public void setPrice(Float price) {
>             this.price = price;
>         }
>     }
> 
> **2、有lombok的实体类** 
> 
>     package com.tgq.model;
>     
>     import lombok.AllArgsConstructor;
>     import lombok.Data;
>     import lombok.NoArgsConstructor;
>     
>     //get、set、tostring
>     @Data
>     //有参构造器
>     @AllArgsConstructor
>     //无参构造器
>     @NoArgsConstructor
>     public class Book {
>         private Integer bid;
>     
>         private String bname;
>     
>         private Float price;
>     
>     }
> 
> 这样看过去就节约了很多的代码
> 
> 当然使用方法是一样的  
>

## 三、Spring Aop集成PageHelper插件 ##

### 1、回顾之前 ###

> 回顾之前我们用的是插件，或者插件和自己写的分页类。
> 
> 例如：
> 
> 1.  配置xml和生成的接口方法
>     
>         <select id="selectPager" resultType="com.tgq.model.Book" parameterType="com.tgq.model.Book">
>                 select
>                 <include refid="Base_Column_List"/>
>                 from t_mvc_book
>                 <where>
>                     <if test="bname != null">
>                         and bname like concat('%',#{bname},'%')
>                     </if>
>                 </where>
>             </select>
>     
>         List<Book> selectPager(Book book);
> 2.  实现接口和接口实现类
>     
>         List<Book> selectPager(Book book, PageBean pageBean);
>     
>         @Override
>             public List<Book> selectPager(Book book, PageBean pageBean) {
>                 if (pageBean != null && pageBean.isPagination())
>                     PageHelper.startPage(pageBean.getPage(), pageBean.getRows());
>                 List<Book> books = bookBiz.selectPager(book);
>                 if (pageBean != null && pageBean.isPagination()) {
>                     PageInfo<Book> info = new PageInfo<>(books);
>                     pageBean.setTotal((int) info.getTotal());
>                 }
>                 return books;
>             }
> 3.  生成测试方法并进行测试
>     
>         @Test
>             public void selectPager() {
>                 Book book = new Book();
>                 PageBean pageBean = new PageBean();
>                 pageBean.setPage(2);
>                 pageBean.setRows(30);
>                 book.setBname("圣墟");
>                 this.bookBiz.selectPager(book, pageBean);
>             }
>     
>     测试结果![a333e6f250f243b69b8413e5f3255b9b.png][]

### 2、优化 ###

> 如何优化我们前面写的代码呢？
> 
>     //        if (pageBean != null && pageBean.isPagination())
>     //            PageHelper.startPage(pageBean.getPage(), pageBean.getRows());
>     //        List<Book> books = bookBiz.selectPager(book);
>     //        if (pageBean != null && pageBean.isPagination()) {
>     //            PageInfo<Book> info = new PageInfo<>(books);
>     //            pageBean.setTotal((int) info.getTotal());
>     //        }
>     //        return books;
> 
> 需要用到环绕通知，编写切面类。

> 所以我们编写一个切面包和**PagerAspect**类
> 
> ![97461507b1174c6d9706584bc6ff530f.png][]
> 
> 1.  在前面写的接口实现类**selectPager**方法进行修改
>     
>         package com.tgq.biz.impl;
>         
>         import com.tgq.biz.BookBiz;
>         import com.tgq.mapper.BookMapper;
>         import com.tgq.model.Book;
>         import com.tgq.utils.PageBean;
>         import org.springframework.beans.factory.annotation.Autowired;
>         import org.springframework.stereotype.Service;
>         
>         import java.util.List;
>         
>         /**
>          * @软件包名 com.tgq.biz.impl
>          * @用户 tgq
>          * @create 2023-08-25 下午4:49
>          * @注释说明：
>          */
>         @Service//仓库的意思
>         public class BookBizImpl implements BookBiz {
>         
>             @Autowired//相当于get、set
>             private BookMapper bookBiz;
>         
>         
>             @Override
>             public List<Book> selectPager(Book book, PageBean pageBean) {
>         
>                 return bookBiz.selectPager(book);
>             }
>         }
> 2.  在切面类PagerAspect里面编写方法，该有的注释也在里面，我这里就不一一的解释了。
>     
>         package com.tgq.aspect;
>         
>         import com.github.pagehelper.PageHelper;
>         import com.github.pagehelper.PageInfo;
>         import com.tgq.utils.PageBean;
>         import org.aspectj.lang.ProceedingJoinPoint;
>         import org.aspectj.lang.annotation.Around;
>         import org.aspectj.lang.annotation.Aspect;
>         import org.springframework.stereotype.Component;
>         
>         import java.util.List;
>         
>         /**
>          * @软件包名 com.tgq.aspect
>          * @用户 tgq
>          * @create 2023-08-25 下午9:26
>          * @注释说明：
>          */
>         @Aspect //代表当前类为切面类
>         @Component //代表该类交给spring进行管理
>         public class PagerAspect {
>             /**
>              * * *..*biz.*Pager(..)
>              * * ： 任意返回值
>              * *..： 任意版本 不限层级
>              * *biz ：以biz结尾的接口/类
>              * *Pager ：以pager结尾的方法
>              * .. ：任意参数
>              * <p>
>              * 符合条件，就是目标或者目标方法
>              *
>              * @param args
>              * @return
>              * @throws Throwable
>              */
>             @Around("execution(* *..*biz.*Pager(..))")
>             public Object invoke(ProceedingJoinPoint args) throws Throwable {
>         //        获取目标方法中的所有参数
>                 Object[] params = args.getArgs();
>                 PageBean pageBean = null;
>                 for (Object param : params) {
>                     if (param instanceof PageBean) {
>         //                强转
>                         pageBean = (PageBean) param;
>                         break;
>                     }
>                 }
>         
>                 if (pageBean != null && pageBean.isPagination())
>                     PageHelper.startPage(pageBean.getPage(), pageBean.getRows());
>         //执行目标方法
>                 Object list = args.proceed(params);
>         
>                 if (null != pageBean && pageBean.isPagination()) {
>                     PageInfo pageInfo = new PageInfo((List) list);
>                     pageBean.setTotal((int) pageInfo.getTotal());
>                 }
>                 return list;
>             }
>         
>         
>         }
> 3.  还是运行上面一样的测试类的方法
>     
>         @Test
>             public void selectPager() {
>                 Book book = new Book();
>                 PageBean pageBean = new PageBean();
>                 pageBean.setPage(2);
>                 pageBean.setRows(30);
>                 book.setBname("圣墟");
>                 this.bookBiz.selectPager(book, pageBean);
>             }
>     
>     测试结果![fd63f0f1fa2f437aaa666e59d19e8a1e.png][]

感谢支持！！！

[aaf7fc5902a0475aad7df47f9d9c101a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/5daa490632624678983ab35ba9d07cbb.png
[be3b4f6f83ef4d31aa46d27d41d06e7b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/40d5a06a38524e2d960f9950c6fbb224.png
[a671fa880b8844718e54aa3fd21f9240.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/9a84f48ed61a4ec1b3cf6d90554dc805.png
[643aa26457964bb1a27e06e93e565b42.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/63a089b6dabd42aca89a7b10ebeb964a.png
[23374ad8a62544ef9d8358606bbc8e9a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/d82b413c0a284ffda55e1e73ec8ccde2.png
[2e8b4b91c299426c8cfa30f61d8119eb.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/b8560c4613fa4f49b4c71e650c5dcb0c.png
[111799a32d3b4a529921b4aca51f5d9a.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/d2df792b086b451ab649c5baccd45a43.png
[d0af56a85fe14041a3dca38fb1581389.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/e750af6a6374462587470ddf29e0920a.png
[0a82c17f899947528a9ef1a101cd4b91.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/75de8c68ee8b41c6bc749a29f102a4e3.png
[7b3d3b222a5e4125851b5e9e9e238452.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/3267e9145ea241f39c8edb41195dbb2e.png
[3454c747084147f3b6d50c1a2a9fa51c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/4afc35bd40044be89065e208fd8acbac.png
[a333e6f250f243b69b8413e5f3255b9b.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/a18a5b16d18b432baf0e5792af95c2b9.png
[97461507b1174c6d9706584bc6ff530f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/ecabb6c750fb4675be475a50de46800e.png
[fd63f0f1fa2f437aaa666e59d19e8a1e.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/13/398ef7d6c49a4d5c912f8e3c8a233a03.png