在Java中是否有等效于Python的exec()函数? [英] Is there an equivalent to Python's exec() function in Java?

问题描述

在python中，您可以使用 exec()执行一段代码.

In python, you can use exec() to execute a piece of code.

在Java中有没有办法做到这一点，所以我可以从字符串中调用函数，还可以做其他事情，例如获取一些用户输入并将其作为Java代码运行.

Is there's any way to do this in Java, so that I can call a function from a string, but also do other things as-well like getting some user input and running it as Java code.

注意:这与中是否存在eval()函数不同在Java中?;那只做 eval()，而我要 exec().

Note: This is not the same as Is there an eval() function in Java?; That only does eval() and I want exec().

推荐答案

您有几个选择

1)动态编译并加载Java类

1) Dynamically compile and load a java classes

如何动态编译和加载外部Java课?

就像彼得·劳里(Peter Lawrey)建议使用net.openhft.compiler，您可以做自己想做的事

Like Peter Lawrey suggests using net.openhft.compiler you can do what you want

https://github.com/OpenHFT/Java-Runtime-Compiler

// dynamically you can call
String className = "mypackage.MyClass";
String javaCode = "package mypackage;\n" +
                 "public class MyClass implements Runnable {\n" +
                 "    public void run() {\n" +
                 "System.out.println(\"Hello World\");\n" +
                 "     }\n" +
                 "}\n";
Class aClass = CompilerUtils.CACHED_COMPILER.loadFromJava(className, javaCode);
Runnable runner = (Runnable) aClass.newInstance();
runner.run();

我测试了此解决方案，并且效果很好.

I tested this solution and it work perfectly.

观察:您需要添加项目的依赖项$ {env.JAVA_HOME}/lib/tools.jar

Observation: You need to add in the dependencies of your project ${env.JAVA_HOME}/lib/tools.jar

2)在Java内部使用另一种语言来解释代码，例如Jython:

2) Use another language inside of your Java that interpret your code, example with Jython:

String arbitraryPythonCode = "";
PythonInterpreter interpreter = new PythonInterpreter();
interpreter.exec(arbitraryPythonCode);

您还可以使用Javascript，Groovy，Scala等

You can also use Javascript, Groovy, Scala, etc.

这篇关于在Java中是否有等效于Python的exec()函数?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！