Solved

Junit assertCollection?

Posted on 2011-03-14
6
411 Views
Last Modified: 2012-05-11
What's the best way to unit test that 2 collections are the same.
(Not the same object, but each element value of one collection is in the other, and vice versa)
0
Comment
Question by:allelopath
  • 4
6 Comments
 
LVL 47

Expert Comment

by:for_yan
ID: 35132060

Are all objects in your collections unique?
Or you may have two equal options present in any of your two collections?

if they are unique then if the sizes of both collections are equal,
and then you just traverse one collection and check that
all elements of this coll;ection are present in the second collection then
tyour collections are the same in the sense you mentioned
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35132107

if my question above has the anser "yes" then this method should work:

boolean areTheyEqual(ArrayList a1, ArrayList a2){
if(a1.size() != a2.size() ) return false;

for(int j=0; j<a1.size(); j++){
if(!a2.contains(a1.get(j)){
return false;
}
}
return true;

}

0
 
LVL 47

Accepted Solution

by:
for_yan earned 500 total points
ID: 35132225

I think this should work even if each collection
has identical items:

boolean areTheyEqual(ArrayList a1, ArrayList a2){
if(a1.size() != a2.size() ) return false;
for(int j =0; j<a1.size(); j++){
int count1 = 0;
for(int k=0; k<a1.size(); k++){
if(a1.get(j).equals(a1.get(k))count1++;

}
int count2 = 0;
for(int k=0; k<a2.size(); k++){
if(a1.get(j).equals(a2.get(k))count2++;

}
if(count1 != count2)return false;

}
retrurn true;

}
0
Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

 
LVL 1

Author Comment

by:allelopath
ID: 35132239
Thanks.
Looks like I could also use Apache Commons CollectionsUtils
CollectionUtils.isEqualCollection(actual, expected);
0
 
LVL 47

Expert Comment

by:for_yan
ID: 35132266
Yes, you are right - that probably would be better.
But it is nice to invent the wheel also :)
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 35132479
coll1.removeAll(coll2);
boolean identical = coll1.size() == 0;
0

Featured Post

Does Powershell have you tied up in knots?

Managing Active Directory does not always have to be complicated.  If you are spending more time trying instead of doing, then it's time to look at something else. For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
starter POM and spring-boot-starter,  spring-boot-web 2 55
JUnit 4 @Before and @BeforeClass differences 3 59
print map entry 34 69
SHA2 certs for IIS AND Java? 2 91
This was posted to the Netbeans forum a Feb, 2010 and I also sent it to Verisign. Who didn't help much in my struggles to get my application signed. ------------------------- Start The idea here is to target your cell phones with the correct…
Java functions are among the best things for programmers to work with as Java sites can be very easy to read and prepare. Java especially simplifies many processes in the coding industry as it helps integrate many forms of technology and different d…
Viewers learn about the scanner class in this video and are introduced to receiving user input for their programs. Additionally, objects, conditional statements, and loops are used to help reinforce the concepts. Introduce Scanner class: Importing…
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…

777 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question