JSONArray轉List>頁面取值
阿新 • • 發佈：2019-01-04
這是簡單的單個鍵值方式的，本文是一組2*2的4張圖片展示存在資料庫的jsonarray格式取出在頁面展示的示例：
1.publicutil類
public class PublicUtil { /** * jsonArray轉List<HashMap<String,String>> * @param json格式字串; * */ //jsonArray格式 /** [ {"pic":"http://address4","order":"4"}, {"pic":"http://address3","order":"3"}, {"pic":"http://address2","order":"2"}, {"pic":"http://address1","order":"1"}] */ public static List<HashMap<String,String>> getPics(String pics) { List<HashMap<String,String>>res = new ArrayList<HashMap<String,String>>(); if(pics==null||pics.equals("")||!pics.startsWith("[")||!pics.endsWith("]")){ return res; } JSONArray jsons = JSONArray.fromObject(pics); JSONObject json = null; HashMap<String,String>map = null; String pic = null; String order = null; for(int i=0;i<jsons.size();i++){ json = jsons.getJSONObject(i); pic = json.getString("pic"); order = json.getString("order"); if(pic!=null&&!"".equals(pic)&&order!=null&&!"".equals(order)){ map = new HashMap<String,String>(); map.put("order",order); map.put("pic",pic.indexOf(".jpg")!=-1?pic:pic+".jpg"); res.add(map); } } //給獲取的list按照order欄位排序 Collections.sort(res, new Comparator<HashMap<String,String>>() { @Override public int compare(HashMap<String, String> o1,HashMap<String, String> o2) { int order1 = Integer.parseInt(o1.get("order")); int order2 = Integer.parseInt(o2.get("order")); System.out.println(order1<order2); if (order1<order2) { return -1; }else{ return 0; } } }); return res; } }
2.Controller類
@Controller public class UserController { @RequestMapping("add") public ModelAndView addInfo(HttpServletRequest reqeust,HttpServletResponse response){ ModelAndView res=new ModelAndView("add"); res.addObject("name", "塔睿"); //json開始，示例 String rels="[{\"pic\":\"地址1\"" + ",\"order\":\"9\"},{\"pic\":\"地址2\"" + ",\"order\":\"8\"},{\"pic\":\"地址3\",\"order\":\"7\"}]"; List<HashMap<String, String>> list= PublicUtil.getPics(rels); res.addObject("list", list); //json結束 //c:forTokens開始 String tags="a~b~c~d~~e"; res.addObject("tags", tags); //c:forTokens結束 return res; } /* * 可以使用如下方法收集資料並生成相應的JSON字串 */ @RequestMapping("one") public void firstOne(){ //宣告一個hash物件並新增資料 Map params=new HashMap(); params.put("name", "名稱1"); params.put("age", "12"); /*params.put("name", "名稱2"); params.put("age", "13");*/ //JSONArray檢查物件型別呼叫正確的工廠方法 //宣告JSONArray物件並輸入json字串 JSONArray array=JSONArray.fromObject(params); //輸出 [{"age":"12","name":"名稱1"}] System.out.println(array.toString()); } }
3.jsp頁面
<%@ page language="java" import="java.util.Map" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%> <% String path = request.getContextPath(); String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort() + path + "/"; Map<String,String> menus=(Map<String,String>)request.getAttribute("menus"); %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> <script type="text/javascript" src="http://apps.bdimg.com/libs/jquery/1.6.4/jquery.min.js"></script> <link href="http://libs.baidu.com/bootstrap/2.3.2/css/bootstrap.min.css" rel="stylesheet"> <script src="http://libs.baidu.com/bootstrap/2.3.2/js/bootstrap.min.js"></script> </head> <body> <form> 獲取：<input type="text" name="name" value="${name }"/><br/> <!-- c:foreach遍歷List<HashMap<String, String>> --> <c:forEach items="${list }" var="lists"> <span>${lists.order }</span> <input type="text" value="${lists.pic }"/><br/> </c:forEach> <!-- c:forTokens用法，delims按照這個進行分割,迴圈的次數也由‘~’個數決定 --> <c:forTokens items="${tags }" delims="~" var="tag"> <input type="text" value="${tag }"/><br/> </c:forTokens> </form> </body> </html>