如何比较两个列表以获取匹配元素和不匹配元素

Question

Below point 1 and point 2 are my input, in below code i'm trying to compare both the Arraylist to get matching and nonmatching elements, But i'm geting only non matching records.

1. arraylist1 = [Check Document Equals, Document Date Like Equals Between, Fund Number Like Equals, Account Number Like Equals In, Tin Like Equals, Company Number Like Equals, Dealer Number Like Equals In, Member Id Like Equals In, Group Id Like Equals In, Account Type Like Equals In, Document Type Code Like Equals In, Print Equals, Test two ]

2. arraylist2 = [Document Date Like Equals Between, Fund Number Equals Like, Account Number Like Equals In, Tin Equals Like, Company Number Equals Like, Dealer Number Like Equals]

3.when i'm trying to remove extra from space "arrayList2" i'm getting below [Document Date LikeEqualsBetween, Fund Number EqualsLike, Account Number LikeEqualsIn, Tin EqualsLike,

4. My code starts from here

    HashSet<String> hs1 = new HashSet<String>(); HashSet<String> hs2 = new HashSet<String>(); for (String match: arraylist2 ) { hs1.add(match); } for (String match: arraylist1) { hs2.add(match); } for (String match: hs2) { boolean b = hs1.add(match); if (b == false) { matchingFields = match; System.out.println("-----------------matching Elements--------------------- = " + matchingFields); } else { nonMatchingFields = match; System.out.println("-----------------Not matching elements--------------------- = " + nonMatchingFields); } }

4.below is the out put i'm getting, You can see i'm getting only nonmatching value there is no matching value.

    --------Not matching elements---------------------  =  Document Type Code Like Equals In
    ---------Not matching elements---------------------  =  Test  two 
   --------Not matching elements---------------------  =  Document Date Like Equals Between
   -----------------Not matching elements---------------------  =  Check Document  Equals 
   -----------------Not matching elements---------------------  =  Member Id Like Equals In
  -----------------Not matching elements---------------------  =  Dealer Number Like Equals In
    -----------------Not matching elements---------------------  =  Print  Equals 
   -----------------Not matching elements---------------------  =  Group Id Like Equals In
-----------------Not matching elements---------------------  =  Fund Number Like Equals 
-----------------Not matching elements---------------------  =  Tin Like Equals 
-----------------Not matching elements---------------------  =  Account Type Like Equals In

-----------------Not matching elements--------------------- = Account Number Like Equals In -----------------Not matching elements--------------------- = Company Number Like Equals

Answer 1

I set this up with a simple main method and it seems to be working for me. You may want to try it with a simple example like mine.

package test;

import java.util.ArrayList;
import java.util.HashSet;

class Test{
    public static void main(String[] args) {
        ArrayList<String> a1 = new ArrayList<String>();
        a1.add("a");
        a1.add("b");

        ArrayList<String> a2 = new ArrayList<String>();
        a2.add("c");
        a2.add("a");
        checkMatch(a1, a2);
    }


    public static void checkMatch(ArrayList<String> arraylist1, ArrayList<String> arraylist2 ) {
        HashSet<String> hs1 = new HashSet<String>();
        HashSet<String> hs2 = new HashSet<String>();
        for (String match : arraylist2 ) {
            hs1.add(match);
        }
        for (String match : arraylist1) {
            hs2.add(match);
        }
        for (String match : hs2) {
            boolean b = hs1.add(match);
            if (b == false) {
                String matchingFields = match;
                System.out.println("-----------------matching Elements--------------------- =  " + 
                        matchingFields);

            } else {
                String nonMatchingFields = match;
                System.out.println("-----------------Not matching elements---------------------  =  " + 
                        nonMatchingFields);
            }
        }
    }
}

Output:

-----------------matching Elements--------------------- = a

-----------------Not matching elements--------------------- = b

Answer 2

You can achieve the same result by using a single hashmap.

import java.util.*;

public class Practice {
    
    public static void main(String[] args) {
         
        ArrayList<String> arraylist1 = new ArrayList<>(Arrays.asList("Check Document Equals" , "Document Date Like Equals Between", "Fund Number Like Equals" , "Account Number Like Equals In", "Tin Like Equals" , "Company Number Like Equals" , "Dealer Number Like Equals In", "Member Id Like Equals In", "Group Id Like Equals In", "Account Type Like Equals In", "Document Type Code Like Equals In", "Print Equals" , "Test two" ));
        ArrayList<String> arraylist2 = new ArrayList<>(Arrays.asList("Document Date Like Equals Between", "Fund Number Equals Like", "Account Number Like Equals In", "Tin Equals Like", "Company Number Equals Like", "Dealer Number Like Equals"));

        HashSet<String> hs = new HashSet<String>(arraylist1);

        for (String match : arraylist2) {
            
            if (hs.contains(match)) {
                System.out.println("-----------------matching Elements--------------------- =  " + match);
            }
            else {                
                System.out.println("-----------------Not matching elements---------------------  =  " + match);
            }
        }

    }
}