创建hashmapfrom List提供java.lang.ClassCastException

Question

下面是我的代码。任何帮助都很感激。我根本无法阅读列表和创建地图。我将列表 object> > 作为函数参数传递到Rest层。在我的服务层中，我需要使用存储在列表中的映射值。

我的列表有前面提到的值

[{ID=56, VALUE=CPR,DESCRIPTOR=HEAD}, 
{ID=68,VALUE=RegFinance,DESCRIPTOR=FINANCE}]

{56={ID=56, VALUE=CPR,DESCRIPTOR=HEAD}, 
68={ID=68,VALUE=RegFinance,DESCRIPTOR=FINANCE}}

    Map<String, Object> userRoleMap = new HashMap<>();
                for (int count = 0; count < allRolesDetails.size(); count++) {
                    //Map<String, Object> mapp=allRolesDetails.get(count);
                   //Above line Gives Exception

                    String[] singleColumn = allRolesDetails.get(count).toString().split(",");
                   //Above line Gives Exception

                    for(String pair : singleColumn)  
                    {
                        String[] entry = pair.split("=");   
                        userRoleMap.put(entry[1].trim(),allRolesDetails.get(count)); 
                        break;//add them to the hashmap and trim whitespaces
                    }
                }

Iterator<Map<String, Object>> it = allRolesDetails.iterator();
            while (it.hasNext()) {
                Map<String, Object> map = it.next(); //so here you don't need a potentially unsafe cast
                for (Map.Entry<String, Object> entry : map.entrySet()) {
                    System.out.println(entry.getKey() + " = " + entry.getValue());
                }
            }

for(Map<String, Object> map:allRolesDetails){
                for(Map.Entry<String, Object>entry : map.entrySet()){
                    String Key=entry.getKey();
                    Object Value=entry.getValue();
                }
            }

ClassCastException：java.lang.String不能强制转换为java.util.Map

Answer 1

您在这里键入了大量代码，而您可以这样做

java prettyprint-override">Map<String, Map<String, Object>> userRoleMap = new HashMap<>();
for (Map<String, Object> m : allRolesDetails) {
    userRoleMap.put(m.get("ID"), m);
}