[英]Comparable is a raw type. References to generic type Comparable<T> should be parameterized
I am setting my my variable like 我将我的变量设置为
Map<String, Function<CLASS_NAME, Comparable>> map = new HashMap<>();
where Comparable
is giving the warning message as 其中
Comparable
发出警告消息为
Comparable is a raw type. References to generic type Comparable<T> should be parameterized
I am using it like 我正在使用它
map.put(VARIABLE_NAME1, s -> s.getStringProperty());
map.put(VARIABLE_NAME2, s -> s.getIntProperty());
..
I am using for compare like 我用于比较喜欢
Comparator<CLASS_TYPE> v = Comparator.comparing(map.get(VARIABLE_NAME), Comparator.nullsFirst(Comparator.naturalOrder()));
What type of Generic should be used to avoid the warning? 应该使用哪种类型的泛型来避免警告?
Comparable is obviously a generic type. 可比显然是通用类型。
So all you need is just: 因此,您只需要:
Map<String, Function<CLASS_NAME, Comparable<CLASSNAME>>> map = new HashMap<>();
instead of 代替
Map<String, Function<CLASS_NAME, Comparable>> map = new HashMap<>();
or you want to compare another type..? 或者您想比较另一种类型..?
Map<String, Function<CLASS_NAME, Comparable<SomeOtherClass>>> map = new HashMap<>();
There are several things wrong with your current scheme. 您当前的方案有几处错误。
Comparator
and Comparable
are two different approaches to comparing objects. Comparator
和Comparable
是比较对象的两种不同方法。 You are confusing the two. Comparator
. Comparator
。 This won't work, as you can't compare a function to anything except another function. VARIABLE_NAME
. VARIABLE_NAME
。 Is that intentional? If you want to create a property map, then you need to create a storable object that can be stored into the map, and can compare its value to a provided value. 如果要创建属性映射,则需要创建一个可存储的对象,该对象可以存储到该映射中,并且可以将其值与提供的值进行比较。 For instance,
例如,
class Storable<T extends Comparable<T>> {
private final T value;
Storable(T value) {
this.value = value;
}
int compareTo(Object other) {
if ( value.getClass().equals(other.getClass()) ) {
return value.compareTo( (T) other );
}
return -1;
}
}
Now create appropriate sub-classes: 现在创建适当的子类:
class StorableInt extends Storable<Integer> {
StorableInt(Integer t) {
super(t);
}
}
class StorableString extends Storable<String> {
StorableString(String s) {
super(s);
}
}
Your property map now looks like: 您的财产地图现在看起来像:
Map<String, Storable<?>>map = new HashMap<>();
map.put(variableName1, new StorableInt(13));
map.put(variableName2, new StorableString("string2"));
<T extends Comparable<T>> int compare( String key, T val ) {
return map.get( key ).compareTo( val );
}
You can now store properties into your map and compare values against those properties. 现在,您可以将属性存储到地图中,然后将这些属性与值进行比较。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.