解决Mybatis-Plus操作分页后数据失效问题

2023-07-10 13:04:03 216

业务场景

我们知道在使用PageHelper分页插件时，会对执行PageHelper.startPage(pageNum,pageSize);方法后的第一条查询语句进行分页操作。在开发中总会遇到这样的业务情景，在进行分页查询后，需要对获得的列表数据包装成另一种类型，此时需要对新类型的列表进行分页，然而由于PageInfo因为泛型的原因，导致处理后的列表不能加入到该类中。

如，我在数据库分页后查询到的类为PageInfo，此时改类中的list属性为User，在当前的业务场景下，我需要将User类型替换为UserVo类型。

当我们对list属性进行操作时，会同时导致PageInfo类中的其他属性发生改变，如total等。

解决方法

//从数据库获得的Users分页列表
//当我们打印users时，会发现打印出来的数据除了列表数据还有分页属性
Listusers=this.list();
//操作users获得的需要的列表
ListuserVos=this.list2(users);
//创建User的info类，此时page中的属性已生成
PageInfouserPage=newPageInfo<>(users);
//创建UserVo的info类
PageInfouserVoPage=newPageInfo<>(userVos);
//将userPage中除看list外的其他属性复制到userVoPage中
PageInfoUtilpageInfoUtil=newPageInfoUtil();
pageInfo=pageInfoUtil.getPageVo(userPage,userVoPage);

pageInfoUtil
publicclassPageInfoUtil{
publicPageInfogetPageVo(PageInfopageInfoPo,PageInfopageInfoVo){
pageInfoVo.setTotal(pageInfoPo.getTotal());
pageInfoVo.setEndRow(pageInfoPo.getEndRow());
pageInfoVo.setHasNextPage(pageInfoPo.isHasNextPage());
pageInfoVo.setHasPreviousPage(pageInfoPo.isHasPreviousPage());
pageInfoVo.setIsFirstPage(pageInfoPo.isIsFirstPage());
pageInfoVo.setIsLastPage(pageInfoPo.isIsLastPage());
pageInfoVo.setNavigateFirstPage(pageInfoPo.getNavigateFirstPage());
pageInfoVo.setNavigateLastPage(pageInfoPo.getNavigateLastPage());
pageInfoVo.setNavigatePages(pageInfoPo.getNavigatePages());
pageInfoVo.setNavigatepageNums(pageInfoPo.getNavigatepageNums());
pageInfoVo.setNextPage(pageInfoPo.getNextPage());
pageInfoVo.setPageNum(pageInfoPo.getPageNum());
pageInfoVo.setPages(pageInfoPo.getPages());
pageInfoVo.setPageSize(pageInfoPo.getPageSize());
pageInfoVo.setPrePage(pageInfoPo.getPrePage());
pageInfoVo.setSize(pageInfoPo.getSize());
pageInfoVo.setStartRow(pageInfoPo.getStartRow());
pageInfoVo.setFirstPage(pageInfoPo.getFirstPage());
pageInfoVo.setLastPage(pageInfoPo.getLastPage());
returnpageInfoVo;
}
}

End

想使用秀一点的方法，结果能力有限，没有成功，只能使用这种笨方法，如果有更好的方法，欢迎各位指导。

补充知识：mybatis-plus分页无效,total=0问题(springmvc)

前言

项目中(springmvc)分页采用mybatis-plus,头一回用,就遇到了如题问题

pom.xml


com.baomidou
mybatis-plus
3.2.0

mapper继承了BaseMapper

@Repository
publicinterfaceUserMapperextendsBaseMapper{
//这里代码没用,查询采用的BaseMapper中的IPageselectPage(IPagepage,@Param("ew")WrapperqueryWrapper);
}

service层

@Override
publicSysUserVolist(UserQoqo){
QueryWrapperqueryWrapper=newQueryWrapper<>();
queryWrapper.like("name",qo.getKeyword())
.or().
like("code",qo.getKeyword());
Pagepage=newPage<>(qo.getPageNo(),qo.getPageSize());
IPageuserPoIPage=userMapper.selectPage(page,queryWrapper);
Listrecords=userPoIPage.getRecords();
longtotal=userPoIPage.getTotal();//总记录数
longpages=userPoIPage.getPages();//查询结果数
longpageNo=userPoIPage.getCurrent();//当前页
longpageSize=userPoIPage.getSize();//每页条数
ListuserVos=Lists.newArrayList();
for(UserPouserPo:records){
IntegeruserId=userPo.getId();
Listroles=userMapper.selectRoles(userId);
UserVouserVo=UserVo.builder().code(userPo.getCode())
.name(userPo.getName())
.rolePo(roles)
.status(userPo.getStatus())
.build();
userVos.add(userVo);
}
SysUserVosysUserVo=SysUserVo.builder()
.list(userVos)
.total(total)
.build();
returnsysUserVo;
}

结果分页并没有生效,于是添加拦截器

packagecom.cebbank.api.config;

importcom.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
importcom.baomidou.mybatisplus.extension.plugins.pagination.optimize.JsqlParserCountOptimize;
importorg.mybatis.spring.annotation.MapperScan;
importorg.springframework.context.annotation.Bean;
importorg.springframework.context.annotation.Configuration;
importorg.springframework.transaction.annotation.EnableTransactionManagement;

@Configuration
@EnableTransactionManagement
@MapperScan("com.cebbank.api.mapper")
publicclassMybatisPlusConfig{
@Bean
publicPaginationInterceptorpaginationInterceptor(){
PaginationInterceptorpaginationInterceptor=newPaginationInterceptor();
//设置请求的页面大于最大页后操作，true调回到首页，false继续请求默认false
paginationInterceptor.setOverflow(true);
//设置最大单页限制数量，默认500条，-1不受限制
paginationInterceptor.setLimit(100);
//开启count的join优化,只针对部分leftjoin
paginationInterceptor.setCountSqlParser(newJsqlParserCountOptimize(true));
paginationInterceptor.setDialectType("mysql");
returnpaginationInterceptor;
}
}

还是没生效

最后找到解决方案,在数据源配置中显式添加分页插件

@Bean
publicSqlSessionFactorysqlSessionFactory()throwsException{
MybatisSqlSessionFactoryBeansqlSessionFactoryBean=newMybatisSqlSessionFactoryBean();
sqlSessionFactoryBean.setDataSource(dataSource());
MybatisConfigurationconfiguration=newMybatisConfiguration();
configuration.setMapUnderscoreToCamelCase(true);
configuration.setDefaultEnumTypeHandler(EnumOrdinalTypeHandler.class);
sqlSessionFactoryBean.setConfiguration(configuration);
//sqlSessionFactoryBean.setMapperLocations(resolveMapperLocations());
sqlSessionFactoryBean.setPlugins(newInterceptor[]{newPaginationInterceptor()});

returnsqlSessionFactoryBean.getObject();
}

完整配置

packagecom.cebbank.api.config;

importcom.alibaba.druid.pool.DruidDataSource;
importcom.baomidou.mybatisplus.core.MybatisConfiguration;
importcom.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;
importcom.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
importorg.apache.ibatis.plugin.Interceptor;
importorg.apache.ibatis.session.SqlSessionFactory;
importorg.apache.ibatis.type.EnumOrdinalTypeHandler;
importorg.mybatis.spring.annotation.MapperScan;
importorg.springframework.beans.factory.annotation.Value;
importorg.springframework.context.annotation.Bean;
importorg.springframework.context.annotation.Configuration;
importorg.springframework.context.annotation.EnableAspectJAutoProxy;
importorg.springframework.jdbc.datasource.DataSourceTransactionManager;

importjavax.sql.DataSource;


/**
*@authorlinyong
*@date2020/7/3016:38
*@description数据源配置
**/
@Configuration
@EnableAspectJAutoProxy
@MapperScan("com.cebbank.api.mapper")
publicclassDBConfig{

@Value("${spring.datasource.url}")
privateStringurl;

@Value("${spring.datasource.driver-class-name}")
privateStringdriverClassName;

@Value("${spring.datasource.username}")
privateStringusername;

@Value("${spring.datasource.password}")
privateStringpassword;

@Value("${spring.datasource.initialSize:5}")
privateIntegerinitialSize;

@Value("${spring.datasource.maxActive:50}")
privateIntegermaxActive;

@Value("${spring.datasource.maxWait:60000}")
privateIntegermaxWait;

@Value("${spring.datasource.minIdle:5}")
privateIntegerminIdle;

@Value("${spring.datasource.testWhileIdle:true}")
privateBooleantestWhileIdle;

@Value("${spring.datasource.testOnBorrow:true}")
privateBooleantestOnBorrow;

@Value("${spring.datasource.testOnReturn:true}")
privateBooleantestOnReturn;

@Value("${spring.datasource.validationQuery:select1}")
privateStringvalidationQuery;

//@Value("${mybatis.mapper-locations}")
//privateStringmapperLocations;


@Bean
publicDataSourcedataSource(){
DruidDataSourcedruidDataSource=newDruidDataSource();
druidDataSource.setUrl(url);
druidDataSource.setDriverClassName(driverClassName);
druidDataSource.setUsername(username);
druidDataSource.setPassword(password);
druidDataSource.setInitialSize(initialSize);
druidDataSource.setMaxActive(maxActive);
druidDataSource.setMaxWait(maxWait);
druidDataSource.setMinIdle(minIdle);
druidDataSource.setTestWhileIdle(testWhileIdle);
druidDataSource.setTestOnBorrow(testOnBorrow);
druidDataSource.setTestOnReturn(testOnReturn);
druidDataSource.setValidationQuery(validationQuery);
returndruidDataSource;
}

//privateResource[]resolveMapperLocations(){
//ResourcePatternResolverresourceResolver=newPathMatchingResourcePatternResolver();
//String[]arr=mapperLocations.split(",");
//Listlocations=Arrays.asList(arr);
//Listresources=newArrayList();
//if(locations!=null){
//for(StringmapperLocation:locations){
//try{
//Resource[]mappers=resourceResolver.getResources(mapperLocation);
//resources.addAll(Arrays.asList(mappers));
//}catch(IOExceptione){
////ignore
//}
//}
//}
//returnresources.toArray(newResource[resources.size()]);
//}

@Bean
publicSqlSessionFactorysqlSessionFactory()throwsException{
MybatisSqlSessionFactoryBeansqlSessionFactoryBean=newMybatisSqlSessionFactoryBean();
sqlSessionFactoryBean.setDataSource(dataSource());
MybatisConfigurationconfiguration=newMybatisConfiguration();
configuration.setMapUnderscoreToCamelCase(true);
configuration.setDefaultEnumTypeHandler(EnumOrdinalTypeHandler.class);
sqlSessionFactoryBean.setConfiguration(configuration);
//sqlSessionFactoryBean.setMapperLocations(resolveMapperLocations());
sqlSessionFactoryBean.setPlugins(newInterceptor[]{newPaginationInterceptor()});

returnsqlSessionFactoryBean.getObject();
}


@Bean
publicDataSourceTransactionManagertransactionManager(){
DataSourceTransactionManagertransactionManager=newDataSourceTransactionManager();
transactionManager.setDataSource(dataSource());
returntransactionManager;
}

}

问题解决！

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解决Mybatis-Plus操作分页后数据失效问题

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