ArrayList 是原始类型.对泛型类型 ArrayList<E> 的引用应该参数化 [英] ArrayList is a raw type. References to generic type ArrayList&lt;E&gt; should be parameterized

问题描述

我有这个方法():

  private List<? extends Map<String, String>> creaListaDeGrupos() {

      ArrayList resultado_padre = new ArrayList();
      for (int i = 0; i < listadoPartidas.getPartidas().size(); i++) {
          HashMap<String, String> padre = new HashMap<String, String>();
          padre.put("posicionLista", posicionlista.get(i));
          padre.put("codigo", codigoBaremo.get(i));
          padre.put("descripcionBaremo", descripcionBaremoPadre.get(i));
          padre.put("cantidad", cantidad.get(i));
          padre.put("importe", importe.get(i));
          padre.put("estado", estado.get(i));
          padre.put("observaciones", observaciones.get(i));
                    resultado_padre.add(padre);
      }
return resultado_padre
}

Lint 返回错误信息:

And Lint return me the error:

ArrayList 是原始类型.对泛型类型 ArrayList 的引用应该被参数化

ArrayList is a raw type. References to generic type ArrayList should be parameterized

但是我做不到

ArrayList<String> resultado_padre = new ArrayList();

因为这不是一个字符串数组列表，那么 bust 是什么类型的?

Because this isnt a arraylist of strings, what type bust will be?

推荐答案

您可以尝试创建与您返回的类型相同的类型:

You could try creating the same type you are returning:

List<HashMap<String, String>> = new ArrayList<HashMap<String, String>>();

不需要声明实现类型，即ArrayList.List 接口更通用，因此在将变量声明为具体类型时，问问自己是否有必要这样做.看针对接口编程

There is no need to declare the implementation type, i.e. ArrayList. The List interface is more general, so when declaring variables as a concrete type, ask yourself if this is necessary. See Programming against interface

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