如何处理 groovy.lang.MissingMethodException

Question

I'm using Groovy in my program because I need to run some pieces of code generated by string. In this very simple example I show my problem related to a very well known error in Groovy.

public static void main(String[] args) {
    Binding binding = new Binding();
    GroovyShell shell = new GroovyShell(binding);
    path(Arrays.asList("A", "B", "C"), Arrays.asList("A", "B"));
    String s = "path(Arrays.asList(\"A\", \"B\", \"C\"), Arrays.asList(\"A\", \"B\"))"; 
    Object value = shell.evaluate(s);
}

private static List<String> path(List<String> dstString, List<String> srcString) {
    System.out.println("it works!");
    return dstString;
}

I pass inline the two Lists using: Arrays.asList("A", "B", "C"), Arrays.asList("A", "B") . When I call the function path with the inline params without involving Groovy it works. But, when I do exactly the same but by Groovy, it fails and returns the following error:

Exception in thread "main" groovy.lang.MissingMethodException: No signature        of method: Script1.path() is applicable for argument types: (java.util.Arrays$ArrayList, java.util.Arrays$ArrayList) values: [[A, B, C], [A, B]]
 Possible solutions: wait(), any(), with(groovy.lang.Closure),    each(groovy.lang.Closure), run(), run()
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:58)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:81)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:52)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:154)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:174)
at Script1.run(Script1.groovy:1)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:585)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:623)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:594)
at Test.main(Test.java:16)

I'm trying to figure out why is not working and how to solve it. Are there any suggestions?

Answer 1

I've solved this problem changing the scope of the function. Seems to be that Groovy is able to execute piece of code inside a string with functions, only if those function are declared in a static way into the class is calling the method evaluate.

Answer 2

You can bypass the current context, or in detail create a binding of it:

sh "echo wurst > any.txt"
def shell = new GroovyShell(new Binding(x:"**/*.txt", y: this))
def script1 = shell.parse("y.archiveArtifacts artifacts: x")
script1.run()

Its another example, but should solve your problem, too.