Accepting java code as user input

Question

I am wondering if there is a way in java to accept java code as user input, and then run it. For example, the user could type in:System.out.println(someMethod.toString());and it would print out the output from someMethod.

I dnt think its possible bcoz java is compiled by the java compiler and run by JRE — Kick, Jan 29 '14 at 14:33
http://stackoverflow.com/questions/4389232/run-piece-of-code-contained-in-a-string — jonhopkins, Jan 29 '14 at 14:39

score 1 · Accepted Answer · edited May 23 '17 at 12:06

1

It can be very dangerous to compile random code written by the user. But you can try using the Java Compiler API, or if you want something similar but not strictly java use groovy then (it is easier to to watch you want with the GroovyShell object)

I haven't tried to do something like this myself, but i found some useful answers here: Convert String to Code

Be very careful if you succeed.

edited May 23 '17 at 12:06

Community

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answered Jan 29 '14 at 14:40

j2e

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Netbeans compiles code written by a user. It's pretty popular, and not really that dangerous. – Rainbolt Jan 29 '14 at 14:41

score 0 · Answer 2 · answered Jan 29 '14 at 14:35

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I dont really know if you can convert user input to runnable code, but you could make the program accept words that are connected to methods.

if(input == someMethod)
{
   someMethod();
}

answered Jan 29 '14 at 14:35

deed

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score 0 · Answer 3 · answered Jan 29 '14 at 15:19

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Take a look at beanshell which can interprit a java string and run the commands.

But be very careful. Giving access to this opens up a HUGE security hole!

answered Jan 29 '14 at 15:19

lance-java

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Accepting java code as user input

3 Answers3