java - 为什么parameter.getType().isInstance(HttpServletRequest.class) return is false,but use "=="is true

Question

Parameter[] ps = method.getParameters();

Map<String,Integer> map = new HashMap<String,Integer>();

for(int ij = 0;ij<ps.length;ij++){

    Parameter p = ps[ij];

    RequestParam rp = p.getAnnotation(RequestParam.class);

    if(rp != null){

        //do something

    }else {
        System.out.println(p.getType());
        System.out.println(p.getType().isInstance(HttpServletRequest.class));
        System.out.println(p.getType() == HttpServletRequest.class);
    }
}

输出是:

interface javax.servlet.http.HttpServletRequest
false
true

为什么使用“isInstance”为假而使用“==”为真？因为“instance of”无法判断implements关系？

Answer 1

该类型不是 HttpServletRequest 类的实例，它是 java.lang.Class 的实例其中包含有关 HttpServletRequest 类的信息。