All language subtitles for 3. Bean Scopes - Write Some Code - Part 2

Alrighty, so let's go ahead
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and pick up where we left off.
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So, the previous video we simply retrieved those beans
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from a container for theCoach and alphaCoach,
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now let's go ahead and just do some more work here.
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So, the first thing I wanna do is check
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to see if these are the same beans.
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So, I'll simply set up a boolean variable result
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and I will actually compare these two.
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I'll compare their object references.
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So, I'll say theCoach equals equal alphaCoach
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and I'll put that in parens
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just to show you that I'm comparing
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these two items, I'm comparing our object reference
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to see if they are pointing to the same area of memory
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or if they're pointing to the same object.
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That's what we're doing here
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with this boolean result equals.
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Now let's go ahead and display the results here
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and so we can see, you know,
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exactly what's going on.
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So, let me set up my quick comment here
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to print out the results
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and I'll use my sysop print line
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and then inside of here
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I'll actually say pointing to the same object
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and then plus result
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and I put a backslash in at the beginning
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of that stream just to give me a character turn
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just so I can have some extra white space
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when I'm looking at the results here of my run.
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Alright, so that's the first one here.
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And then I also wanna actually print out
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the memory location for each one of these.
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So, I'll say the memory location for theCoach
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and then I'm just doing a plus theCoach
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and so by default,
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the default version of this display here,
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it'll call the two string method of this object,
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and the default implementation of the two strings,
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it'll simply be the class name
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and the internal memory address
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for that given object reference.
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So, I'll do a similar thing here for alphaCoach.
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Alright, that looks okay,
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and I'll add an extra character turn
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just to make the output look pretty.
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And also I'll be nice, add a Spring container
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and I'll close the context.
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Alright, so that's kind of it.
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So, you know, we already read in the config up top,
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then we retrieved the bean from the container,
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we moved down and we just checked the result
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to see if they were the same,
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and then we print out the result
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and we also print out the memory location
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for theCoach and alphaCoach.
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Oh actually, let me fix that quick typo here.
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So, pointing, I put a colon space right there
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on line 22 just to make my output
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look a little bit prettier.
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Alright, so run as Java application
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and good stuff here.
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Alright, let's check out this output.
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Okay, great, so first off
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it says, you know, loading XML bean definitions
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from this file, beanScope-applicationContext,
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so that's our new file that we just created
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and so we are reading that file which is good,
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and then here's the print out of the results
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pointing to the same object is true,
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and also we have the memory location for theCoach
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which is 5e85
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and also the memory location for alphaCoach 5e85,
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so basically those numbers are the same,
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so it's actually printing to the same area of memory
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for both of these objects.
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So, that's great.
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Now let's go ahead and switch this up.
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Let's test this with scope equals prototype.
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So, scope equals prototype means that it'll actually create
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a new object every time we request it.
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So, here I'll say scope equals prototype
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in the config file.
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Alright, so this looks good,
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so let's go equals prototype,
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so I'm gonna create a new object for each request.
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Let's go ahead and save this file
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and now all we need to do is go back
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to the bean scope demo app
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and then just run it.
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No changes here, everything here stays the same.
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Just right click and choose run as.
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Alright, so looking at the output.
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Okay, now, okay, reading from that config
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beanScope-appContext,
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now it says pointing to the same object is false.
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Whoa, yeah, 'cause it's a prototype, right?
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So that means that they create a new object
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for each reference, alright?
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So, theCoach has one memory address
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and then alphaCoach has a different memory address,
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so these are two separate objects,
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two separate areas of memory
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because again, right, we using the prototype scope.
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Alright, so nice little example here
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of making use of singleton scope
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and prototype scope
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and here you're able to see the output,
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see the results and so on.
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So, you should feel very comfortable now with bean scopes.
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So again, the default is singleton
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and it's only one instance
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and then you can also specify prototype scope
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which will create a new one for each request.
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Alright, you're ready,
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you're ready for a Spring job interview.
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Alright, cool, good stuff.
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So, I'll see you the next video.