從零搭建本身的SpringBoot後臺框架(七)

時間 2019-11-16

標籤搭建本身 springboot 後臺框架欄目 Spring 简体版

原文原文鏈接

Hello你們好，本章咱們添加PageHelper分頁查詢功能。有問題能夠聯繫我mr_beany@163.com。另求各路大神指點，感謝

一：什麼是PageHelper

PageHelper是一款好用的開源免費的Mybatis第三方物理分頁插件mysql

物理分頁git

支持常見的 12 種數據庫。Oracle,MySql,MariaDB,SQLite,DB2,PostgreSQL,SqlServer 等github

支持多種分頁方式spring

支持常見的RowBounds(PageRowBounds)，PageHelper.startPage 方法調用，Mapper 接口參數調用sql

二：添加PageHelper依賴

<dependency>
   <groupId>com.github.pagehelper</groupId>
   <artifactId>pagehelper-spring-boot-starter</artifactId>
   <version>1.2.5</version>
</dependency>複製代碼

而後鼠標右鍵選擇Maven→Reimport進行依賴下載
數據庫

三：添加PageHelper配置

在application.properties中添加bash

logging.level.com.example.demo.dao=DEBUG
pagehelper.helperDialect=mysql
pagehelper.reasonable=true
pagehelper.supportMethodsArguments=true
pagehelper.params=count=countSql
pagehelper.page-size-zero=true複製代碼

四：使用方法

UserInfoMapper.xmlapp

<select id="selectAll" resultMap="BaseResultMap">
    select
    <include refid="Base_Column_List"/>
    from user_info
</select>複製代碼

UserInfoMapper
ide

List<UserInfo> selectAll();複製代碼

UserInfoServicespring-boot

PageInfo<UserInfo> selectAll(Integer page,Integer size);複製代碼

UserInfoServiceImpl

@Override
public PageInfo<UserInfo> selectAll(Integer page, Integer size) {
    //開啓分頁查詢，寫在查詢語句上方
    //只有緊跟在PageHelper.startPage方法後的第一個Mybatis的查詢（Select）方法會被分頁。
    PageHelper.startPage(page, size);
    List<UserInfo> userInfoList = userInfoMapper.selectAll();
    PageInfo<UserInfo> pageInfo = new PageInfo<>(userInfoList);
    return pageInfo;
}複製代碼

UserInfoController

@ApiOperation(value = "查詢用戶", notes = "分頁查詢用戶全部")
@ApiImplicitParams({
        @ApiImplicitParam(name = "page", value = "當前頁碼",
                dataType = "Integer", paramType = "query"),
        @ApiImplicitParam(name = "size", value = "每頁顯示條數",
                dataType = "Integer", paramType = "query")
})
@PostMapping("/selectAll")
public RetResult<PageInfo<UserInfo>> selectAll(@RequestParam(defaultValue = "0") Integer page,
                                      @RequestParam(defaultValue = "0") Integer size) {
    PageInfo<UserInfo> pageInfo = userInfoService.selectAll(page, size);
    return RetResponse.makeOKRsp(pageInfo);
}複製代碼

五：PageHelper中默認PageInfo的成員變量介紹

//當前頁
private int pageNum;
//每頁的數量
private int pageSize;
//當前頁的數量
private int size;
//當前頁面第一個元素在數據庫中的行號
private int startRow;
//當前頁面最後一個元素在數據庫中的行號
private int endRow;
//總記錄數
private long total;
//總頁數
private int pages;
//結果集
private List<T> list;
//第一頁
private int firstPage;
//前一頁
private int prePage;
//是否爲第一頁
private boolean isFirstPage;
//是否爲最後一頁
private boolean isLastPage;
//是否有前一頁
private boolean hasPreviousPage;
//是否有下一頁
private boolean hasNextPage;
//導航頁碼數
private int navigatePages;
//全部導航頁號
private int[] navigatepageNums; 複製代碼

六：功能測試

地址：http://192.168.1.104:8080/userInfo/selectAll

狀況一：不傳參數，默認爲全查詢

{
    "code": 200,
    "data": {
        "endRow": 2,
        "firstPage": 0,
        "hasNextPage": false,
        "hasPreviousPage": false,
        "isFirstPage": false,
        "isLastPage": true,
        "lastPage": 0,
        "list": [
            {
                "id": 1,
                "userName": "Mr_初晨"
            },
            {
                "id": 2,
                "userName": "Mr_初晨"
            }
        ],
        "navigateFirstPage": 0,
        "navigateLastPage": 0,
        "navigatePages": 8,
        "navigatepageNums": [],
        "nextPage": 0,
        "orderBy": "",
        "pageNum": 0,
        "pageSize": 0,
        "pages": 0,
        "prePage": 0,
        "size": 2,
        "startRow": 1,
        "total": 2
    },
    "msg": "success"
}複製代碼

狀況二：參數 page=2&size=1

{
    "code": 200,
    "data": {
        "endRow": 2,
        "firstPage": 1,
        "hasNextPage": false,
        "hasPreviousPage": true,
        "isFirstPage": false,
        "isLastPage": true,
        "lastPage": 2,
        "list": [
            {
                "id": 2,
                "userName": "Mr_初晨"
            }
        ],
        "navigateFirstPage": 1,
        "navigateLastPage": 2,
        "navigatePages": 8,
        "navigatepageNums": [
            1,
            2
        ],
        "nextPage": 0,
        "orderBy": "",
        "pageNum": 2,
        "pageSize": 1,
        "pages": 2,
        "prePage": 1,
        "size": 1,
        "startRow": 2,
        "total": 2
    },
    "msg": "success"
}複製代碼