在做项目的时候,涉及到分页,记录一个mybatis比较简单的分页方式——PageHelper。
在添加分页之前,首先先添加maven依赖。如果不是maven项目,直接导入jar到lib也是一样的。
<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/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.dawn</groupId>
<artifactId>app</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>app Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>3.2.12.RELEASE</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.0</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.0</version>
</dependency>
<dependency>
<groupId>commons-dbcp</groupId>
<artifactId>commons-dbcp</artifactId>
<version>1.4</version>
</dependency>
<dependency>
<groupId>jstl</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.3.1</version>
</dependency>
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
<dependency>
<groupId>commons-codec</groupId>
<artifactId>commons-codec</artifactId>
<version>1.10</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-mapper-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-tx</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.8.5</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.8.5</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>2.8.5</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.9</version>
</dependency>
<dependency>
<groupId>org.codehaus.jackson</groupId>
<artifactId>jackson-core-asl</artifactId>
<version>1.9.13</version>
</dependency>
<dependency>
<groupId>net.sourceforge.jtds</groupId>
<artifactId>com.springsource.net.sourceforge.jtds</artifactId>
<version>1.2.2</version>
</dependency>
<dependency>
<groupId>javaee</groupId>
<artifactId>javaee-api</artifactId>
<version>5</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.3.RELEASE</version>
</dependency>
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.1.2</version>
</dependency>
</dependencies>
<build>
<finalName>app</finalName>
<plugins>
<!-- define the project compile level -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
其中<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper</artifactId>
<version>5.1.2</version>
</dependency>
就是要分页的依赖。其他的都是为了配置ssm框架所导入的包。
然后添加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">
<!-- 配置管理器 -->
<configuration>
<plugins>
<!-- com.github.pagehelper为PageHelper类所在包名 -->
<plugin interceptor="com.github.pagehelper.PageInterceptor">
</plugin>
</plugins>
</configuration>
这是我的项目的文件结构。
spring-mvc.xml内容如下
<?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-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/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
<!--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SpringMVC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>
<!-- 对静态资源的访问 -->
<!-- <mvc:resources mapping="/js/**" location="/js/" /> <mvc:resources mapping="/css/**"
location="/css/" /> -->
<!-- 自动扫描该包,使SpringMVC认为包下用了@controller注解的类是控制器 -->
<context:component-scan base-package="com.dawn.controller" />
<!-- 添加注解驱动 -->
<mvc:annotation-driven/>
<!-- <mvc:annotation-driven enable-matrix-variables="true" /> -->
<!-- 允许对静态资源文件的访问 -->
<!-- <mvc:default-servlet-handler /> -->
<!-- 定义跳转的文件的前后缀 ,视图模式配置 -->
<!-- <bean
class="org.springframework.web.servlet.view.InternalResourceViewResolver">
这里的配置我的理解是自动给后面action的方法return的字符串加上前缀和后缀,变成一个 可用的url地址
<property name="prefix" value="/WEB-INF/jsp/" />
<property name="suffix" value=".jsp" />
</bean>
-->
<!-- 配置文件上传,如果没有使用文件上传可以不用配置,当然如果不配,那么配置文件中也不必引入上传组件包 -->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 默认编码 -->
<property name="defaultEncoding" value="UTF-8" />
<!-- 文件大小最大值 -->
<property name="maxUploadSize" value="10485760000" />
<!-- 内存中的最大值 -->
<property name="maxInMemorySize" value="40960" />
</bean>
</beans>
这是spring-mybatis.xml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-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/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">
<!-- 自动扫描 -->
<context:component-scan base-package="com.dawn" />
<!-- 引入配置文件 -->
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value="classpath:config/jdbc.properties" />
</bean>
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName" value="${driver}" />
<property name="url" value="${url}" />
<property name="username" value="${username}" />
<property name="password" value="${password}" />
</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:mappers/*.xml"></property>
<property name="configLocation" value="classpath:config/mybatis-config.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="com.dawn.mapper" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean>
<!-- (事务管理)transaction manager, use JtaTransactionManager for global tx -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="dataSource" />
</bean>
</beans>
还有数据库的配置文件 jdbc.properties
driver=net.sourceforge.jtds.jdbc.Driver
url=jdbc:jtds:sqlserver://192.168.1.3:1433;databaseName=bbh
username=db123
password=88
然后在mapper.xml的,写普通 的查询语句就好
<select id="queryOne" resultMap="messageMap">
<!-- select * from dggc1.dbo.mybook where xm=#{receiverName} and fsr=#{senderName}
and fsrq=#{sendDate} and sfflag=#{sfflag} -->
select * from dggc1.dbo.mybook where pkid=#{pkid}
</select>
如果需要分页,在写调用mapper.xml的接口的时候要提前添加
PageHelper.startPage(1, 20);这个分页的代码。表示当前第一页,显示20条记录。。。
下面是我的测试的代码,这仅仅是个使用分页的例子
@Test
public void testQueryAll() {
MessageMapper massageMapper = ctx.getBean("messageMapper",MessageMapper.class);
PageHelper.startPage(1,3);//分页的代码
List<Message>massages=massageMapper.queryAll("A");
for(Message i:massages)
System.out.println(i);
}
这就是pagehelper比较简单的做法。