java - 如何解析由静态方法组成的字符串以便我们可以调用它？

Question

我正在尝试编写一个函数，该函数接收一个字符串，该字符串由一个静态方法组成，并以字符串数组作为参数。

例如，假设我们有一个带有静态方法的类:

package com.stack.examples;

public class Example {

   public static void testMethod() {
       System.out.println("method executed");
    }
}

现在，我们的函数将位于另一个类中，如下所示:

package com.stack.functions;

public class Functions {

   public void parseCommand(String command) {
      //TODO, this is where my doubts lie
      //The given string is always composed of a sequence of Java identifiers 
        //separated by the character ’.’, representing the full qualified name of 
          //a Java method (package.class.method)
       command.execute(); //Would this work? Perhaps reflection would be ideal

   }
}

我的目标是解析在 parseCommand 中作为参数给出的字符串，以便

parseCommand("com.stack.examples.Example.testMethod()");

实际上使用给定的参数调用静态方法(在本例中，该方法只会打印出“消息已执行”)。

Answer 1

在寻找解决此问题的替代方案后，我发现reflection对我来说很有效:

要执行的静态方法:

package test;

public class Example {
    public static void testMethod() {
        System.out.println("method executed");
    }
}

主类:

package test;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class Main {

    public static void reflectVulnerableMethod(String str) throws ClassNotFoundException, NoSuchMethodException, SecurityException,
                    IllegalAccessException, IllegalArgumentException, InvocationTargetException {
        String[] parts = str.split("\\.");

        String forKlazz = "";
        for (int i=0; i<parts.length -1; i++) {
            if (i != 0){
                forKlazz += '.' + parts[i];
            }
            else forKlazz += parts[i];
        }
        Class<?> klazz = Class.forName(forKlazz);
        Method m = klazz.getMethod(parts[parts.length-1]);


        m.invoke(null);


    }

    public static void main(String[] args) {
        try {
            reflectVulnerableMethod("test.Example.testMethod");
        } catch (ClassNotFoundException | NoSuchMethodException | SecurityException | IllegalAccessException
                | IllegalArgumentException | InvocationTargetException e) {
            e.printStackTrace();
        }
    }
}