protected FilterExpression parseFilter()

in scim-spec/scim-spec-schema/src/main/java/org/apache/directory/scim/spec/filter/Filter.java [70:91]

• 19 lines of code
• 2 McCabe index (conditional complexity)

  protected FilterExpression parseFilter(String filter) throws FilterParseException {
    FilterLexer l = new FilterLexer(new ANTLRInputStream(filter));
    FilterParser p = new FilterParser(new CommonTokenStream(l));
    p.setBuildParseTree(true);

    p.addErrorListener(new BaseErrorListener() {
      @Override
      public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine, String msg, RecognitionException e) {
        throw new IllegalStateException("failed to parse at line " + line + ":" + charPositionInLine + " due to " + msg, e);
      }
    });

    try {
      ParseTree tree = p.filter();
      ExpressionBuildingListener expListener = new ExpressionBuildingListener();
      ParseTreeWalker.DEFAULT.walk(expListener, tree);
      
      return expListener.getFilterExpression();
    } catch (IllegalStateException e) {
      throw new FilterParseException("Failed to parse filter: " + filter, e);
    }
  }