last one

Question about the task

Introducing tags

Java Core, Level 9, Lesson 11

Resolved

last question is how to sort hashmap by integer key

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.*; import java.util.HashMap; import java.util.Map; import java.util.Stack; import java.util.TreeMap; public class Solution { public static void main(String[] args) throws IOException { BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in)); String fileName = bufferedReader.readLine(); bufferedReader.close(); String tag = ""; if (args.length > 0) tag = args[0]; //String tag = "span"; //String file = "C:\\Users\\Wei\\Desktop\\input.txt"; StringBuilder sb = new StringBuilder(); BufferedReader br = new BufferedReader(new FileReader(fileName)); while(br.ready()) sb.append(br.readLine()); br.close(); String line = sb.toString(); String openTag = "<" + tag; String closeTag = "</" + tag + ">"; String openIcon = "开"; String closeIcon= "关"; line = line.replaceAll(openTag, openIcon) .replace(closeTag, closeIcon) .substring(line.indexOf(openTag)); Stack<Integer> stack = new Stack<>(); HashMap<Integer, String> lineMap = new HashMap<>(); int count = 0; String[] arr = line.split(""); for (int i = 0; i < arr.length; i++) { if (arr[i].equals(openIcon)) { stack.push(i); } if (arr[i].equals(closeIcon)) { int currentPosition = stack.pop(); lineMap.put(currentPosition,line.substring(currentPosition, i+1)); } } TreeMap sortedMap = new TreeMap(); sortedMap.putAll(lineMap); String newLine; for(Map.Entry<Integer, String> pair : lineMap.entrySet()) { newLine = pair.getValue().replace(openIcon,openTag).replace(closeIcon, closeTag); System.out.println(pair.getKey() + "---" + newLine); } } }

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Fadi Alsaidi

Level 34 , Carrollton, TX, USA

19 April 2020, 18:42

You need to try this more rigid example posted by a great user. Code GYM gave and easy example, as you already seen a lot of people are getting the correct output. try the below and if you are able to get the correct answer then you should be good to go. Tips: 1- make sure your starting index is the very next open tag every single time . Don't start from the last closed tag unless you use it as a starting point to find the next open tag. 2- make sure you account for nested tags

Wei Cui

Level 39 , Newark, United States

29 March 2020, 03:48

solution

line 33-40: since tag start with "<tag" end with "</tag>, so use one char to instead, hence its easily to populate to find all open and close tag; line 42-55 : using stack to store open tag, because characteristic of stack if first come last out, so once find close tag, it can pull of correspond open tag based on question requirement, needing print out by sequence, so i store each pair start position and store position and string into hashmap; my solution just change start from line 57:

//sort position first and then print correspond string
ArrayList<Integer> list = new ArrayList<>();
for(Map.Entry<Integer, String> pair : lineMap.entrySet()) {
    //replace tag back to string
    list.add(pair.getKey());
}
Collections.sort(list);
for (int i : list) {
    String newLine = lineMap.get(i).replace(openIcon, openTag).replace(closeIcon, closeTag);
    System.out.println(newLine);
}