Write a Java program that meets the following requirements:- Using up to and inc

Question

Write a Java program that meets the following requirements:-
Using up to and including Chapter 20 concepts.
Find in the EBook at the end of the chapter, “#20.11 Match Grouping Symbols”
You might want to check out the “StringTokenizer” class to use in this program

20.11 (Match grouping symbols): A Java program contains various pairs of grouping symbols such as:

Parentheses: ( and )

Braces: { and }

Brackets: [ and ]

Note that the grouping symbols cannot overlap. For example, (a { b ) } is illegal. Write a program to check whether a Java source-code file has correct pairs of grouping symbols. Pass the source-code file name as a command-line argument.

Explanation / Answer

import java.io.File;
import java.io.FileInputStream;
import java.util.HashMap;
MatchingPairs.java :
__________________

public class MatchingPairs {
   public static void main(String[] args) {
      
       try{
           File file = new File(args[0]);
           FileInputStream fis = new FileInputStream(file);
           HashMap<Character,Integer> hmp = new HashMap<Character, Integer>();
           while(fis.available() > 0){
                   char ch =(char)fis.read();
                   if(ch == '(' || ch == ')'){
                       if(hmp.containsKey('('))
                           hmp.put('(',hmp.get('(')+1);
                       else
                           hmp.put('(',1);
                   }
                   else if(ch == '{' || ch == '}'){
                       if(hmp.containsKey('{'))
                           hmp.put('{',hmp.get('{')+1);
                       else
                           hmp.put('{',1);
                   }
                   else if(ch == '[' || ch == ']'){
                       if(hmp.containsKey('['))
                           hmp.put('[',hmp.get('[')+1);
                       else
                           hmp.put('[',1);
                   }
           }
           boolean flag = true;
           for(char key : hmp.keySet()){
               int count = hmp.get(key);
               if(count%2 == 0)
                   continue;
               else
                   flag = false;
           }
           if(flag)
               System.out.println("'"+file.getName()+"' source-code file has correct pairs of grouping symbols.");
           else
               System.out.println("'"+file.getName()+"' source-code file not has correct pairs of grouping symbols.");
           fis.close();
       }
       catch(Exception e){
           e.printStackTrace();
       }
   }
}

input.txt :
________

hello kanakala lakshmna rao
{welcom(e to our}inchegg(in vizag[ what about your family]em dng{
)hello})wh[atsup] bye.

Passing File as Command Line argument:
___________________________________

java MatchingPairs F:\input.txt

Sample Output:

'input.txt' source-code file has correct pairs of grouping symbols.

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