时间:2020-11-07 22:06:45 | 栏目:JAVA代码 | 点击:次
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
<select id="selectUsersByPage" parameterType="int" resultMap="UserMap"> SELECT * number from user limit #{page},10 </select>
查询user表,从第page项开始,每次返回10条数据
2.index.jsp
<html> <head> <title>page</title> <link rel="stylesheet" type="text/css" href="css/index.css" rel="external nofollow" > </head> <body> <div style="width: 100%;margin-top:20px;"> <table> <tr style="background-color: #F5F5F5;"> <th>username</th> <th>password</th> <th>sex</th> <th>email</th> <th>createTime</th> <th>updateTime</th> </tr> <div id = "show_data"> <c:choose> <c:when test="${ulist != null}"> <c:forEach items="${ulist}" var="u"> <tr> <td>${u.username}</td> <td>${u.password}</td> <td>${u.sex}</td> <td>${u.email}</td> <td><fmt:formatDate value="${u.create_time}" type="date"/></td> <td><fmt:formatDate value="${u.update_time}" type="date"/></td> </tr> </c:forEach> </c:when> <c:otherwise> <tr> <td></td> <td></td> <td></td> <td></td> <td></td> </tr> </c:otherwise> </c:choose> </div> </table> <div class="page"> <div class="page_cell">首页</div> <div class="page_cell" ip="up_page">上一页</div> <div style="float: left;margin: 2px"><%=session.getAttribute("page")%>/${ulist[0].number}</div> <div class="page_cell" onclick="next_page(<%=session.getAttribute("page")%>)">下一页</div> <div class="page_cell">末页</div> </div> </div> </body> <script type="text/javascript" src="js/index.js"></script> <script type="text/javascript" src="js/jquery.js"></script> </html>
3.css
body{ width: 100%; margin: 0; } table{ border:1px solid red; text-align: center; margin: auto; border-collapse: collapse; } tr{ border: 1px solid #ddd } th{ width: 150px; font-weight: 700; height: 36px; } td{ height: 36px; } .page{ margin: auto; width: 300px; text-align: center; margin-top: 10px; } .page_cell{ float: left; width: 50px; border:1px solid #F5F5F5; margin:2px; cursor: pointer; } .page_cell:hover{ -webkit-box-shadow: #777 0px 0px 1px; }
4.js
/** * 下一页 */ function next_page(page){ var data = { "page":page }; $.ajax({ type:"post", url:"/RoleControl/next_page.do", data:JSON.stringify(data), dataType:"json", contentType:"application/json", success:function(data){ var show_data = document.getElementById("show_data") show_data.innerHTML = " "; for(i=0; i<data.length; i++){ //.....异步刷新页面 } }, error:function(data){ alert("网络连接错误"); } }); }
5.控制器
@RequestMapping("/index.do") public String index(ModelMap map, HttpSession session){ session.setAttribute("page",1); List<User> ulist = userService.selectUsersByPage(0); map.put("ulist",ulist); return "index"; } /** * 用户信息分页查询 * @param params * @return */ @RequestMapping(value = "/next_page.do",method = RequestMethod.POST) @ResponseBody public String getUsersByPage(@RequestBody JSONObject params){ // Map<String,String> paramsMap = JSON.parseObject(params,new TypeReference<Map<String,String>>(){}); System.out.println(params.get("page").toString()); List<User> ulist = userService.selectUsersByPage(Integer.parseInt(params.get("page").toString())*10); return JSON.toJSONString(ulist); }
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>
ByteArrayHttpMessageConverter StringHttpMessageConverter ResourceHttpMessageConverter SourceHttpMessageConverter XmlAwareFormHttpMessageConverter Jaxb2RootElementHttpMessageConverter 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:
<dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>2.5.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.5.2</version> </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:
begin declare pid int; set pid = 10000; while pid>0 DO insert into user values (pid,'pw','sex','email',now(),now()); set pid = pid-1; end while; end