public void printException() {
        if (exception != null) {
            for (ConversionException exc : exception) {
                exc.print();
            }
            exception = null;
        }
    }
Convert the specified file Read each line and ask matcher implementation
for conversion Rewrite the line returned by matcher

@param file
slf4j-migrator/src/main/java/org/slf4j/migrator/ProjectConverter.java