做网站教程pdf营销策划方案ppt

SpringBoot之整合PageHelper分页插件

详细配置请查看官网或MyBatis分页插件之PageHelper详细介绍-CSDN博客

1. 引入坐标

<!--pagehelper--><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper-spring-boot-starter</artifactId><version>1.3.0</version><!--排除pagehelper的依赖mybatis和mybatis-spring的jar包以免与mybatis-plus的冲突，导致报NoClassFound org.mybatis.logging.LoggerFactory--><exclusions><exclusion><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId></exclusion><exclusion><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId></exclusion></exclusions></dependency>

2. application.yml配置

pagehelper:helper-dialect: mysqlreasonable: truesupport-methods-arguments: trueparams: count=countSql

3. 基本使用

    @Autowiredprivate PublicService publicService;	   @GetMapping(value = "/getUserList")public Result<PageInfo> getUserList(@RequestParam(name="pageNo", defaultValue="1") Integer pageNo,@RequestParam(name="pageSize", defaultValue="5") Integer pageSize){StringBuffer sql = new StringBuffer();sql.append("SELECT\n" +" a.id,\n" +" a.username,\n" +" b.id AS file_id,\n" +" b.file_url,\n" +" b.file_size,\n" +"FROM\n" +" sys_user a\n" +" LEFT JOIN sys_file b ON a.id = b.parent_id \n" +"WHERE\n" +" a.del_flag = '0'");Result result = new Result<>();Map map = new HashMap(5);map.put("sql",sql.toString());//获取第pageNo页，pageSize条内容，默认查询总数countPageHelper.startPage(pageNo, pageSize);//紧跟着的第一个select方法会被分页List<Map<String, Object>> mapList = publicService.sqlQuery(map);result.setResult(mapList);result.setSuccess(true);PageInfo pageInfo = new PageInfo(mapList);return Result.OK(pageInfo);

4. 对多个查询执行分页

Pagehelper中只有紧跟在 PageHelper.startPage 方法后的第一个 Mybatis 的查询（Select）方法会被分页。

1. 默认第一个Select语句会执行分页

案例代码如下：

 
@Autowired
private PublicService publicService;public List<SignatureUser> getUserList(){//获取第pageNo页，pageSize条内容，默认查询总数countPageHelper.startPage(pageNo, pageSize);//紧跟着的第一个select方法会被分页List<Map<String, Object>> mapList = publicService.sqlQuery(map);IPage iPage = IPageUtil.pageData(mapList);//下面这个查询不会分页List<SignatureUser> signatureUserList = publicService.getSignatureUserList(map);System.out.println(signatureUserList.size());return signatureUserList;
}

2. 让Pagehelper也能执行多个分页的方法

在查询参数中设置pageNum与pageSize参数使其第二个查询也能分页，如下：

@Autowired
private PublicService publicService; public List<SignatureUser> getUserList(){//获取第pageNo页，pageSize条内容，默认查询总数countPageHelper.startPage(pageNo, pageSize);//紧跟着的第一个select方法会被分页List<Map<String, Object>> mapList = publicService.sqlQuery(map);IPage iPage = IPageUtil.pageData(mapList);System.out.println("第一个查询分页结果",iPage);Map map1 = new HashMap(3);//加入mybatis分页的参数pageNum与pageSize则其他查询也能分页map1.put("pageNum", pageNo);map1.put("pageSize", pageSize);List<SignatureUser> signatureUserList = publicService.getSignatureUserList(map1);System.out.println(signatureUserList.size());return signatureUserList;
}

3. 完整案例

    @Autowiredprivate PublicService publicService; @ApiOperation(value = "用户信息列表", notes = "用户信息列表")@GetMapping(value = "/getUserList")public Result<?> getUserList(@RequestParam(name="pageNo", defaultValue="1") Integer pageNo,@RequestParam(name="pageSize", defaultValue="5") Integer pageSize){StringBuffer sql = new StringBuffer();sql.append("SELECT\n" +" a.id,\n" +" a.username,\n" +" b.id AS file_id,\n" +" b.file_url,\n" +" b.file_size,\n" +"FROM\n" +" sys_user a\n" +" LEFT JOIN sys_file b ON a.id = b.parent_id \n" +"WHERE\n" +" a.del_flag = '0'");//一.直接sql方式分页Map map = new HashMap(5);map.put("sql",sql.toString());//获取第pageNo页，pageSize条内容，默认查询总数countPageHelper.startPage(pageNo, pageSize);//紧跟着的第一个select方法会被分页List<Map<String, Object>> mapList = publicService.sqlQuery(map);IPage iPage = IPageUtil.pageData(mapList);//return Result.OK(iPage);//二.对象集合分页Map map1 = new HashMap(3);map1.put("pageNum", pageNo);map1.put("pageSize", pageSize);List<SignatureUser> signatureUserList = publicService.getSignatureUserList(map1);System.out.println(signatureUserList.size());return Result.OK(IPageUtil.pageData(signatureUserList));}