jdk8遍历list＜map＞获取某个字段准换成map的方法

List<Map<String,Object>> columnList =(List<Map<String,Object>>) dayMaps.get("columnList");
                        columnList.stream().forEach(map -> {
                            columnMap.put((String) map.get("deviceCode"),map.get("deviceName"));
                        });

 遍历map

columnMap.forEach((k,v)->{
                    Map<String,Object> m= new HashMap<>();
                    m.put("deviceCode",k);
                    m.put("deviceName",v);
                    columnList.add(m);
                });