springboot+mybatis+thymeleaf利用pagehelper實現多條件查詢+分頁

我們都知道在開發過程中多條件查詢+分頁一直是一個老生常談得問題，那么今天就來淺談一下springboot是如何實現得，要想實現分頁這個功能那我們就得在確定每頁顯示行數得情況下知道總頁數等等一些變量，當然，這些變量都可以通過查詢數據庫得知，今天所要講的是如何在查詢一遍數據庫得前提下得到這些變量以及我們多條件查詢出來得變量集合，話不多話，請看代碼

前台頁面代碼

<form  th:action="@{'/user/findUserByCondition'}">
                            
                            
         <input name="username" class="form-control" id="H_user" type="text"
                                    placeholder="請輸入用戶名..." />
                            
                            
        <input name="email" class="form-control" id="H_key" type="text"
                                    placeholder="請輸入郵箱..." />
                            
                            
        <input type="submit" value="查詢" />
                            
</form>

這里我用的是form表單得形式傳數據，當然也可以用ajax得形式，如果用ajax得形式傳數據得話那controller層就得變化了，因為需要接受你傳過來得數據，感興趣得朋友可以自己試一試

<div>
                                <div class="clearfix">
                                    <ul class="pagination m-b-5 pull-right">
                                        <li th:if="${users.hasPreviousPage}"><a
                                            th:href="@{'/user/touser?pageIndex='+${users.prePage}}"
                                            aria-label="Previous"> <i class="fa fa-angle-left"></i>&nbsp;上一頁
                                        </a></li>

                                        <th:block th:each="nav : ${users.navigatepageNums}">
                                            <li th:class="${nav==users.pageNum}?'active':''"><a
                                                th:href="@{'/user/touser?pageIndex='+${nav}}"
                                                th:text="${nav}"></a></li>
                                        </th:block>

                                        <th:block th:if="${users.hasNextPage}">
                                            <li><a
                                                th:href="@{'/user/touser?pageIndex='+${users.nextPage}}"
                                                aria-label="Next"> 下一頁&nbsp;<i class="fa fa-angle-right"></i>
                                            </a></li>
                                        </th:block>

                                        <li><span th:text="'共'+${users.pages}+'頁'"></span></li>
                                    </ul>
                                </div>
                            </div>

這是分頁得功能，簡而言之，就是上一頁下一頁或者跳轉到哪一頁等等

@RequestMapping("/touser")
    public String toUser(@RequestParam(value = "pageIndex", defaultValue = "1") Integer pageIndex,
            @RequestParam(value = "pageSize", defaultValue = "4") Integer pageSize, HttpServletRequest request,
            HttpServletResponse response) {
//        UserVoExample userVoExample = new UserVoExample();
//        userVoExample.setOrderByClause("created desc");
//        userVoExample.createCriteria();
//        
//        
//        userVoExample.setUsername(Common.username);
//        userVoExample.setEmail(Common.email);
        
        ConditionUser conditionUser=new ConditionUser();
        conditionUser.setUsername(Common.username);
        conditionUser.setEmail(Common.email);
        
        PageInfo<User> pageInfoUsers = userService.getUserWithPage1(conditionUser, pageIndex, pageSize);
        request.setAttribute("users", pageInfoUsers);
        return "user_page";
    }

    @RequestMapping("/findUserByCondition")
    public String findUserByCondition(User user,
            @RequestParam(value = "pageIndex", defaultValue = "1") Integer pageIndex,
            @RequestParam(value = "pageSize", defaultValue = "4") Integer pageSize, HttpServletRequest request) {
//        UserVoExample userVoExample = new UserVoExample();
//        userVoExample.setOrderByClause("created desc");
//        userVoExample.createCriteria();
        
        
        
        
        
        Common.username = user.getUsername();
        Common.email = user.getEmail();
        
        String tusername=Common.username;
        String temail=Common.email;
        
        ConditionUser conditionUser=new ConditionUser();
        conditionUser.setUsername(tusername);
        conditionUser.setEmail(temail);
//        userVoExample.setUsername(tusername);
//        userVoExample.setEmail(temail);
        
        PageInfo<User> pageInfoUsers = userService.getUserWithPage1(conditionUser, pageIndex, pageSize);
        request.setAttribute("users", pageInfoUsers);
        return "user_page";
    }

 

這是控制層得代碼，里面得Common是提供得一個公共類，用於存放查詢得多條件，代碼如下：

//公共類
public class Common {

    public static String username=null;
    public static String email=null;
    
}

上述控制層還牽扯到一個PageInfo類，這個類中擁有上一頁，下一頁，總頁數等等屬性，是專門為我們分頁量身打造得

下面看我們得Service層

@Override
    public PageInfo<User> getUserWithPage1(ConditionUser conditionUser, Integer pageIndex, Integer pageSize) {
        PageHelper.startPage(pageIndex, pageSize);
        List<User>users=userDao.findUserByCondition(conditionUser);
        
        return new PageInfo<>(users, 3);
    }

上述代碼得ConditionUser類是多條件得類以及分頁，具體代碼如下

package com.gateway.entity;

public class ConditionUser {

    
    private String username;
    private String email;
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public ConditionUser(String username, String email) {
        super();
        this.username = username;
        this.email = email;
    }
    public ConditionUser() {
        super();
        // TODO Auto-generated constructor stub
    }
    @Override
    public String toString() {
        return "ConditionUser [username=" + username + ", email=" + email + "]";
    }
    
}

 

剩下得就是dao層得接口以及mapper得xml文件了，還有查出來得集合在頁面上顯示，這里就不寫代碼了