Question

I have written a code which can reduce the grammatical boundaries for a text, but when I run the program this exception comes up

java.lang.ClassCastException

here is the class that i run,

public class paerser {
public static void main (String [] arg){
    LexicalizedParser lp = new LexicalizedParser("grammar/englishPCFG.ser.gz");
        lp.setOptionFlags("-maxLength", "500", "-retainTmpSubcategories");
        TreebankLanguagePack tlp = new PennTreebankLanguagePack();
       GrammaticalStructureFactory gsf = tlp.grammaticalStructureFactory();
       String text = "John, who was the CEO of a company, played golf.";
       edu.stanford.nlp.trees.Tree parse = lp.apply(Arrays.asList(text));
       GrammaticalStructure gs = gsf.newGrammaticalStructure(parse);
       List<TypedDependency> tdl = gs.typedDependenciesCCprocessed();
       System.out.println(tdl);

}
}

Updated,

here is the full stack trace …

Loading parser from serialized file grammar/englishPCFG.ser.gz ... done [1.5 sec].
Following exception caught during parsing:
java.lang.ClassCastException: java.lang.String cannot be cast to edu.stanford.nlp.ling.HasWord
    at edu.stanford.nlp.parser.lexparser.ExhaustivePCFGParser.parse(ExhaustivePCFGParser.java:346)
    at edu.stanford.nlp.parser.lexparser.LexicalizedParser.parse(LexicalizedParser.java:386)
    at edu.stanford.nlp.parser.lexparser.LexicalizedParser.apply(LexicalizedParser.java:304)
    at paerser.main(paerser.java:19)
Recovering using fall through strategy: will construct an (X ...) tree.
Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be  cast to edu.stanford.nlp.ling.HasWord
    at edu.stanford.nlp.parser.lexparser.LexicalizedParser.apply(LexicalizedParser.java:317)
    at paerser.main(paerser.java:19)

Answer 1

Stacktrace shows that ExhaustivePCFGParser’s parse method is being used. It expects a List of HasWord objects. You are passing a list of String. Hence, the exception.

public boolean parse(List<? extends HasWord> sentence) { // ExhaustivePCFGParser