ssm整合实现分页查询
一、通过limit查询语句实现分页，并展示
1.mapper.xml配置
1 <select id="selectUsersByPage" parameterType="int" resultMap="UserMap">
2 SELECT * number from user limit #{page},10
3 </select>
查询user表，从第page项开始，每次返回10条数据
2.index.jsp
1 <html>
2 <head>
3 <title>page</title>
4 <link rel="stylesheet" type="text/css" href="css/index.css">
5 </head>
6 <body>
7 <div style="width: 100%;margin-top:20px;">
8 <table>
9 <tr style="background-color: #F5F5F5;">
10 <th>username</th>
11 <th>password</th>
12 <th>sex</th>
13 <th>email</th>
14 <th>createTime</th>
15 <th>updateTime</th>
16 </tr>
17 <div id = "show_data">
18 <c:choose>
19 <c:when test="${ulist != null}">
20 <c:forEach items="${ulist}" var="u">
21 <tr>
22 <td>${u.username}</td>
23 <td>${u.password}</td>
24 <td>${u.sex}</td>
25 <td>${u.email}</td>
26 <td><fmt:formatDate value="${u.create_time}" type="date"/></td>
27 <td><fmt:formatDate value="${u.update_time}" type="date"/></td>
28 </tr>
29 </c:forEach>
30 </c:when>
31 <c:otherwise>
32 <tr>
33 <td></td>
34 <td></td>
35 <td></td>
36 <td></td>
37 <td></td>
38 </tr>
39 </c:otherwise>
40 </c:choose>
41 </div>
42 </table>
43 <div class="page">
44 <div class="page_cell">首页</div>
45 <div class="page_cell" ip="up_page">上一页</div>
46 <div style="float: left;margin: 2px"><%=session.getAttribute("page")%>/${ulist[0].number}</div>
47 <div class="page_cell" onclick="next_page(<%=session.getAttribute("page")%>)">下一页</div>
48 <div class="page_cell">末页</div>
49 </div>
50 </div>
51 </body>
52 <script type="text/javascript" src="js/index.js"></script>
53 <script type="text/javascript" src="js/jquery.js"></script>
54 </html>
3.css
1 body{
2 width: 100%;
3 margin: 0;
4 }
5 table{
6 border:1px solid red;
7 text-align: center;
8 margin: auto;
9 border-collapse: collapse;
10 }
11 tr{
12 border: 1px solid #ddd
13 }
14 th{
15 width: 150px;
16 font-weight: 700;
17 height: 36px;
18 }
19 td{
20 height: 36px;
21 }
22 .page{
23 margin: auto;
24 width: 300px;
25 text-align: center;
26 margin-top: 10px;
27 }
28 .page_cell{
29 float: left;
30 width: 50px;
31 border:1px solid #F5F5F5;
32 margin:2px;
33 cursor: pointer;
34 }
35 .page_cell:hover{
36 -webkit-box-shadow: #777 0px 0px 1px;
37 }
4.js
1 /**
2 * 下一页
3 */
4 function next_page(page){
5 var data = {
6 "page":page
7 };
8 $.ajax({
9 type:"post",
10 url:"/RoleControl/next_page.do",
11 data:JSON.stringify(data),
12 dataType:"json",
13 contentType:"application/json",
14 success:function(data){
15 var show_data = document.getElementById("show_data")
16 show_data.innerHTML = " ";
17 for(i=0; i<data.length; i++){
18 //.....异步刷新页面
19 }
20 },
21 error:function(data){
22 alert("网络连接错误");
23 }
24 });
25 }
5.控制器
1 @RequestMapping("/index.do")
2 public String index(ModelMap map, HttpSession session){
3 session.setAttribute("page",1);
4 List<User> ulist = userService.selectUsersByPage(0);
5 map.put("ulist",ulist);
6 return "index";
7 }
8
9 /**
10 * 用户信息分页查询
11 * @param params
12 * @return
13 */
14 @RequestMapping(value = "/next_page.do",method = RequestMethod.POST)
15 @ResponseBody
16 public String getUsersByPage(@RequestBody JSONObject params){
17 // Map<String,String> paramsMap = JSON.parseObject(params,new TypeReference<Map<String,String>>(){});
18 System.out.println(params.get("page").toString());
19 List<User> ulist = userService.selectUsersByPage(Integer.parseInt(params.get("page").toString())*10);
20 return JSON.toJSONString(ulist);
21 }
问题:在ajax传递json对象的时候，发生了415错误(未知媒体错误)
原因：
<mvc:annotation-driven />会自动注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter两个bean ，AnnotationMethodHandlerAdapter将会初始化7个转换器，可以通过调用AnnotationMethodHandlerAdapter的getMessageConverts()方法来获取转换器的一个集合 List<HttpMessageConverter>
1 ByteArrayHttpMessageConverter 2 StringHttpMessageConverter 3 ResourceHttpMessageConverter 4 SourceHttpMessageConverter 5 XmlAwareFormHttpMessageConverter 6 Jaxb2RootElementHttpMessageConverter 7 MappingJacksonHttpMessageConverter
解决：对于json的解析就是通过MappingJacksonHttpMessageConverter转换器完成的。所以就需要加入jackson依赖包：
1 <dependency> 2 <groupId>com.fasterxml.jackson.core</groupId> 3 <artifactId>jackson-core</artifactId> 4 <version>2.5.2</version> 5 </dependency> 6 7 <dependency> 8 <groupId>com.fasterxml.jackson.core</groupId> 9 <artifactId>jackson-databind</artifactId> 10 <version>2.5.2</version> 11 </dependency>
加了依赖包后问题就完美解决了，运行结果如下：
以上查询的数据是通过存储过程批量插入的：
1 begin 2 declare pid int; 3 set pid = 10000; 4 while pid>0 DO 5 insert into user values (pid,‘pw‘,‘sex‘,‘email‘,now(),now()); 6 set pid = pid-1; 7 end while; 8 end
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时间： 2024-08-30 17:27:57