MapToJson
package com.wlc.test; import java.util.HashMap; import java.util.Map; import com.fasterxml.jackson.core.type.TypeReference; import com.fasterxml.jackson.databind.ObjectMapper; import net.sf.json.JSON; import net.sf.json.JSONObject; /** * map转json json转map * * @author Administrator * */ public class MapToJson { public static void main(String[] args) { // 需求：将map类型的数据转成json Map map = new HashMap (); map.put("id", "1"); map.put("name", "张三"); map.put("pass", "123"); JSONObject json = new JSONObject(); JSONObject jb =json.fromObject(json); String str = json.fromObject(map).toString(); System.out.println(str); User user = (User) JSONObject.toBean(jb, User.class); System.out.println("user" + user); // 需求：将json格式转成map类型的数据 Map map2 = new HashMap (); ObjectMapper mapper = new ObjectMapper(); try { map = mapper.readValue(str, new TypeReference<HashMap >() { }); System.out.println("map" + map); String id = (String) map.get("id"); String name = (String) map.get("name"); String pass = (String) map.get("pass"); System.out.println("id=" + id + "&" + "name" + "&" + name + "pass" + "&" + pass); } catch (Exception e) { e.printStackTrace(); } } } ListToJson package com.wlc.test; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import net.sf.json.JSONArray; import net.sf.json.JSONObject; /** * 需求：json转list * list转json * @author Administrator * */ public class ListToJson { @SuppressWarnings("deprecation") public static void main(String[] args) { List<Map<String, Object>> list = new ArrayList<Map<String,Object>>(); Map<String,Object> map1 = new HashMap<String,Object>(); map1.put("id", "1"); map1.put("name", "zhangsan"); map1.put("pass", "123"); list.add(map1); Map<String,Object> map2 = new HashMap<String,Object>(); map2.put("id", "2"); map2.put("name", "lisi"); map2.put("pass", "456"); list.add(map2); Map<String,Object> map3 = new HashMap<String,Object>(); map3.put("id", "3"); map3.put("name", "wangwu"); map3.put("pass", "789"); list.add(map3); //需求 将 list数据转成 Json String str = JSONArray.fromObject(list).toString(); System.out.println(str); //需求 ：JsonArray类型的json数据 存放在List<User>>中去 JSONArray ja = JSONArray.fromObject(str); List<Map<String,Object>> ls = JSONArray.toList(ja, HashMap.class); //查看ls的长度 System.out.println("ls的长度是"+ls.size()); List<User> lu = new ArrayList<>(); for (Map<String, Object> map : ls) { User user = new User (); String id =(String) map.get("id"); String name =(String) map.get("name"); String pass =(String) map.get("pass"); user.setId(id); user.setName(name); user.setPass(pass); lu.add(user); } System.out.println(lu); //需求 ：JsonArray类型的json数据 存放在List<Map<String,String>>中去 List<Map<String,Object>> ls2 = JSONArray.toList(ja, HashMap.class); for (Map<String, Object> map : ls2) { StringBuffer sb = new StringBuffer() ; if(map.containsKey("id")){ sb.append(map.get("id")); } if(map.containsKey("name")){ sb.append(map.get("name")); } if(map.containsKey("pass")){ sb.append(map.get("pass")); } System.out.println("sb=="+sb.toString()); } } } jsonObject = JSONObject.parseObject(rnt); }catch(Exception e){ e.printStackTrace(); WebUtils.forward(request, response, "/knowledge/knwlg_error.jsp"); } int ccou = Integer.parseInt(jsonObject.get("itemCount").toString());
