Works with the example, but not passing

Question about the task

Introducing tags

Java Core, Level 9, Lesson 11

Resolved

The codes works with multiple args keywords and nested tags, but still not passing, any thoughts?

Read from the console the name of a file containing HTML.

Example:
Info about Leela Leela Turanga
Supergirl

The main method's first parameter is a tag name. For example, "span".
Display all tags that match the specified tag.
The order should match their order in the file, each tag on a new line.
The number of spaces, newline characters (\n), or carriage returns (\r) does not affect the result.
The file does not have a CDATA tag. Each opening tag has a separate closing tag, and there are no self-closing tags.
Tags may have nested tags.

Example output:
Leela Turanga Leela Turanga Super girl

Tag templates:
<tag>text1</tag> <tag text2>text1</tag> <tag text2>text1</tag>

text1 and text2 can be empty

Requirements:

The program must read the file name from the console (use BufferedReader).
The BufferedReader used for reading input from the console must be closed after use.
The program must read the file's contents (use FileReader).
The file input stream (FileReader) must be closed.
The program must write to the console all the tags that match the tag specified by the argument passed to the main method.

package com.codegym.task.task19.task1918; /* Introducing tags */ import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.Stack; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Solution { public static void main(String[] args) throws IOException { String fileName; BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); fileName = reader.readLine(); BufferedReader fileReader = new BufferedReader(new FileReader(fileName)); String newLine; String fileString; StringBuilder sb = new StringBuilder(); while ((newLine=fileReader.readLine())!=null) { sb.append(newLine); } fileString = sb.toString().replaceAll("\\n\\r", ""); reader.close(); fileReader.close(); Pattern pattern = Pattern.compile("<.+?>"); Matcher matcher = pattern.matcher(fileString); List<List<String>> tagList = new ArrayList<>(); while (matcher.find()) { List<String> tempList = new ArrayList<>(); tempList.add(matcher.group()); tempList.add(String.valueOf(matcher.start())); tempList.add(String.valueOf(matcher.end())); tagList.add(tempList); } Stack<String> tagStack = new Stack<>(); List<String> printList = new ArrayList<>(); for (int i = 0; i < tagList.size(); i++) { String tag = tagList.get(i).get(0); if (Arrays.stream(args).anyMatch(tag::contains) && !tag.startsWith("</")) { Integer startIndex = Integer.valueOf(tagList.get(i).get(1)); tagStack.push(tagList.get(i).get(0)); innerWhileBlock: while (!tagStack.empty()) { for (int j = i + 1; j < tagList.size(); j++) { if (!tagList.get(j).get(0).startsWith("</")) { tagStack.push(tagList.get(j).get(0)); } else if (tagList.get(j).get(0).startsWith("</")) { if (tagStack.peek().contains(tagList.get(j).get(0).replace("/", "") .replace("<", "").replace(">", ""))) { tagStack.pop(); if (tagStack.empty()) { Integer endIndex = Integer.valueOf(tagList.get(j).get(2)); String outputString = fileString.substring(startIndex, endIndex); printList.add(outputString); break innerWhileBlock; } } } } } } } printList.forEach(System.out::println); } }

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Guadalupe Gagnon

Level 37 , Tampa, United States

14 October 2020, 15:11

on line 34, remove everything after .toString(), the BufferedReader.readline() method already removes new lines and carriage returns. The problem with this code is line 39. The open tags are both <TAG and <TAG>, but this line will not pick up the first variation Suggestions: The pattern used on that line is too broad, it is picking up all tags instead of just the tag that is specified in args, which then requires an additional step to filter out the ones you don't need. The pattern used should be "</?" + args[0], this will fill tagList with the locations of all the proper open and closing tags. Also, filling the tagList with only the start number if it is an open tag and only the end number if it is a closing tag could simplify the next few steps (make sure to add 1 to the closing number if you dont include the closing angle bracket in the pattern". This is all that is needed to get the proper substring at line 74. For example, if it is a starting tag enter this ["OPEN", startNumber], and a closing ["CLOSE", endNumber +1].

Davedabull

Level 22 , New York City, United States

14 October 2020, 16:43

Thank you for your comment Guadalupe! I replaced line 59 with this

for (String s : args) {
    if (tag.startsWith("<"+s)) {

and it passed. The problem was I am using "contains" instead of "startswith" to test open tag I saw this comment somewhere and I used this example to debug my code: iniput: ^[1] wiki 2 (there's a space after the last letter a in the first line) the correct output should be: [1] wiki 2 Thank you again for your advices! This question has bugged me for so long, such a relief!

Guadalupe Gagnon

Level 37 , Tampa, United States

14 October 2020, 16:55

useful

Obviously, with code, there are multiple ways to arrive at the same solve. I fixed your code one way by changing line 39 to:

Pattern pattern = Pattern.compile("</?" + args[0]);

and then line 74 to:

String outputString = fileString.substring(startIndex, endIndex + 1);

While you were able to find a solution by changing line 59 to those 2 lines. That is also an easy change to get your code to work.

Davedabull

Level 22 , New York City, United States

14 October 2020, 21:06

Now I look at the question again and I realize there's only one argument. I kept thinking there might be multiple html tags, like instead of only "span", the input might be "span" and "b", that's why I did all the looping. 😑😑 But yea thank you again for your advice!

Guadalupe Gagnon

Level 37 , Tampa, United States

15 October 2020, 14:15

Glad I could help. You did a good job on this task and I liked your creative solution.