反射地基于静态类生成可实例化的类 [英] Generate an instantiable class based on a static class reflectively

问题描述

我可以(假设使用反射功能)创建一个类，其方法名称与 java.lang.Math 相同，并且每个方法都将其转发给 Math 吗?

Can I (using reflection I presume?) create a class with all the same method names as java.lang.Math and each method just forwards it to Math?

例如

public class MyMath {
  public MyMath() {}

  public double abs(double a) {
    return Math.abs(a);
  }

  public float abs(float a) {
    return Math.abs(a);
  }

  public int abs(int a) {
    return Math.abs(a);
  }

  ...

  public double acos(double a) {
    return Math.acos(a);
  }
  
  ...

我该如何以编程方式生成它?

How could I generate this programmatically?

推荐答案

您可以通过反射来获得Math类的实例:

You can do this with reflection to get an instance of class Math:

try {
    Constructor[] cs = Math.class.getDeclaredConstructors();
    cs[0].setAccessible(true);
    Math m = (Math) cs[0].newInstance();
    //e.g.
    System.out.println(m.sqrt(16));
}
catch (Exception e) {
    e.printStackTrace();
}

这是否明智的做法是另一个问题.

Whether this is a sensible thing to do is another question.

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