Basically I want to be able to do be able to parse a JavaScript-like syntax. For example:
var results = system.function('example');
if(results == "hello") {
console_print("ding dong.");
}
So basically you get it, results will be a "string" and system.function will call a Java method, and those results will go into the results string.
I want to be able to do basic math, and validation in this as well, but I want this done in Java. Any ideas?
If you're willing to use JavaScript (not just JavaScript-like), and you're using Java 1.6+, then you can use the Scripting API:
import javax.script.*;
public class Main {
public static void main (String[] args) throws Exception {
String source =
"var system = new Array(); \n" +
"system['foo'] = function(s) { return 'hello'; } \n" +
" \n" +
"var results = system.foo('example'); \n" +
" \n" +
"if(results == \"hello\") { \n" +
" print(\"ding dong.\"); \n" +
"} \n";
ScriptEngine engine = new ScriptEngineManager().getEngineByName("JavaScript");
engine.eval(source);
}
}
which will print:
ding dong.
to the console.
And to invoke Java methods from the scripting language, you could give BeanShell a try:
package test;
import bsh.Interpreter;
public class Main {
public static void foo(Object param) {
System.out.println("From Java, param=" + param);
}
public static void main (String[] args) throws Exception {
Interpreter i = new Interpreter();
i.eval("a = 3 * 5; test.Main.foo(a);");
}
}
which will print:
From Java, param=15
The core interpreter JAR of BeanShell is only 143 KB: more lightweight than that will be difficult, IMO.
\n, " and +? manually or any shortcut?
String source = ""; and IntelliJ made sure the quotes were properly escaped and added line-breaks for me.
I think you can use Rhino for this. Rhino is an javascript engine that can be embedded in java.
