Java - 将字符串作为普通代码运行 [英] Java - Run a string as normal code

问题描述

有没有办法将字符串作为代码运行?我的意思是，如果我运行了一个具有值 System.out.println("Hello World) 的字符串，我是否可以将字符串作为普通代码运行，然后输出将是 Hello World?

Is there a way to run a string as code? I mean if I had a string run having value System.out.println("Hello World) could I run the string as normal code the then output will be Hello World?

例如:

String code = "System.out.println("Hello World)";

code.run(); //I know this doesn't work

控制台:

Hello World

推荐答案

你想要相当于 JavaScript 的 eval.Java 中没有等价物.

You want the equivalent of JavaScript's eval. There is no equivalent in Java.

嗯，有，但这不是微不足道的.

Well, there is but it's not trivial.

您可以生成包含该代码的类的完整源代码.类似的东西

You can generate the full source code of a class containing that code. Something like

public class StuffToDynamicallyCompile  {
   public static final void main(String[] ignored)  {
       PUT STUFF HERE!
   }
}

然后以编程方式调用编译器，如此答案中所述，或如评论中所述:如何从java程序中编译.java文件

And then programatically invoke the compiler, as described in this answer, or as stated in the comments: How to compile .java file from within java program

不是一个简单的任务.也许有一种方法可以最大限度地减少您的要求，因此您可以允许一组极其有限的命令，只需使用开关执行它(如果 'dothis' 然后调用 doThis(), else if 'doThat'，调用 doThat() 等).

Not a simple task. Perhaps there's a way to minimize your requirements, so you can allow an extremely limited set of commands, and just execute it with a switch ("if 'dothis' then call doThis(), else if 'doThat', call doThat(), etc.).

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