Spring Tutorial 05 - ApplicationContext and Property Initialization

We'll first replace the BeanFactory with the more powerful ApplicationContext. We'll then make Spring initialize a property of an object by specifying the value in the configuration XML.

[@ehsanr720]

watching in 2019 :) till this year this guy is the best in the field

[@lets_do_it1154]

same here bro.

[@ThangNguyen-ko5ze]

All the other tutorials are a pain in the ass

[@satyasahoo9573]

True in 2020 even

[@venkychowdary]

@@satyasahoo9573 in 2021 as well

[@Armaan944]

isnt this series outdated ?? shall i see some newly uploaded spring series?? or will this be good enough?

[@0x28]

This man is one of the best teachers in the world.

[@funkybuddha1598]

watching in 2020.. best spring framework intro course!! Thank you!!

[@8o8inSquares]

Oh now spring makes a lot of sense for me!

[@CryptoJaat]

Hello Andrej, As Koushik mentioned that we can do all these locally of course. The reason we are using spring is to able to inject these from the outside and change the properties without having to recompile and redeploying the application again and for more control and flexibility.
hope that helps.

[@2s_company_]

Your tutorials are a life saver! Amazing videos.

[@MukulTripathi]

Awesome ... I'm awake at 3:30 am watching this ...

[@bittooaggarwal5776]

basically here we can set template for multiple objects with different values preset for member variables otherwise in our main class we need to make multiple and set properties for them one by one.
eg:

[@raxitraju2439]

Hello everyone, if you are facing the errors like spring.xml couldn't be found or triangle.java couldn't be found, try this-
PS: I'm using Spring 4.2.4, Maven with JDK 8 and Eclipse Oxygen 3A
1. Move Spring.xml to the place where your triangle.java and drawingapp.java are.
2. In DrawingApp.java write-
ApplicationContext context = new ClassPathXmlApplicationContext("file:src/main/java/Spring.xml");
3. In Spring.xml write-

That's it, this worked smoothly for me.

[@Lunariann]

Been stuck on a "file not found" exception since the last video and tried everything--moving my xml file, updating class path, etc. Thank you for posting this fix! Is it good practice for the bean file to be in the same folder? My issue was with the xml file. I'm also using Maven and JDK 8.

[@arunmaharana8002]

Excellent tutorial ............that gave me a lot of concept on spring....Thank you

[@7Shol]

Does the Property form the xml file, use the Setter?
Edit: Yes according to the next playlist's video 👍

[@lingasodanapalli615]

Can someone explain me this please? If the xml file itself assigns the value of "Equilateral" to the member variable "type" of that object which is being returned, then why are we again writing the setType(String type) method?

[@ffflfa1203]

How does preconfiguring Beans via xml differ from just assigning these values in the constructor of the class? i have serious issues understanding the advantage of this.

[@walidbousseta2650]

the way you explain think are great, in additional to your great tuto you should share some resource with geeks for exampe the XML file you just create or at laest the code lines in it, and thank you for this hard work you are doing in this tuto.

[@Java.Brains]

@shoibmd Any package name should do. Regarding the Spring XML error, check if you have the hierarchy right. First you need to have a beans element and under that, individual bean elements.

[@AniketSomwanshi-ll7mz]

Considering this is 10 years old, is it okay to learn Spring 3 or are there major changes in Spring 5?

[@Anonymous-fy2el]

Core Spring is still the same with some newer features.

[@shimondoodkin]

context usually should be closed
to do it need to be casted to
ConfigurableApplicationContext
that has that close method.
ApplicationContext context=new ClassPathXmlApplicationContext("file:spring.xml");
Triangle triangle=(Triangle)context.getBean("triangle");
triangle.draw();
((ConfigurableApplicationContext)context).close();

[@kanekaab]

Hi ,with ApplicationContext object reference i didnt get the value of pre set member variable of the bean which we set in spring.xml . ...i got the value with BeanFactory's object reference in the same case where in this tutorial it suggests to use ApplicationContext object reference ...can you tell me why

[@azaharnawaz8471]

wow excellent work koushik

[@SaiRamtechie]

I have a question , why can't just make a simple class Triangle and we can extend this class whenever we need. What's the difference ?

[@AruneshSrivastava]

why we are moving "spring.xml" into src folder. ... is that FileSystemResource searching into the whole application ... and ClassPathXmlApplicationContext is searching for "spring.xml" only in the src folder ?

[@chavvz]

hi Koushik,
Can't i set the 'type' variable mentioned in this tutorial without using getter and setter methods like this ....
public class triangle {
public String type;

public void draw(){
System.out.println(type + " Triangle drawn");
}
}
In doing so i am getting an error saying cannot set the value for type...

[@pedrotavares41]

The variable type you are trying to call is a local variable. To call the type variable you defined before, use "this", so will be like this: this.type + "Triangle drawn"

[@munishtyro]

you are just EXCELLENT . thank you very much

[@cueballdoe4779]

Is the ApplicationContext using the setter method in assigning the value? or is it somehow directly assigning the value to the private attribute?

[@jasonl412]

Do you know reflection of Java? reflection can assign value to private variable.

[@SurajBajaj]

Please increase your video resolution. 720p or even 480p is good enough. It's clearly visible.

[@MukulTripathi]

Waiting for more tutorials in the series!

[@AKASHYADAV-gq8sc]

A very basic question: Why use getType()? why not type variable directly?what difference does it makes

[@swiffty1]

Still don't see the point of assigning values to the Triangle members in the XML file. Just do it in the object itself and when the bean factory creates the object for you the values will be there with it

[@nocontrol813]

For file not found problem:
1) if spring.xml is at the root of the project, type: ClassPathXmlApplicationContext("file:spring.xml");
because file: prefix points to file system resources, not the classpath
2) if spring.xml is in src/main/resources/, type: ClassPathXmlApplicationContext("spring.xml");
without prefix. It will work without specifiying the path.

[@nocontrol813]

Addendum: 2) if spring.xml is in src/main/resources/, or in src

[@mirceskiandrej]

your tutorials are AWESOME!
I went through the JSP and servlet ones in two days. it was enjoyable studying with them.
but I have a question, wouldn't it be the same if in the triangle class we just had a constructor like this:
public Triangle(){
this.type="Equilateral";
}
the result would be the same... I mean, everything that we can initialize in xml, we can also do in the constructor. I am sure that there is a reason for this, but I dont understand it yet

[@Suraj-pf6ic]

It did not work for me. I did same thing as explained here:
ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
Triangle triangle = (Triangle) context.getBean("triangle");
triangle.draw();
and my path I moved to source path. Also I changed the path as new ClassPathXmlApplicationContext("file:src/spring.xml");
nothing worked.

[@trimedu3187]

just add this line
((AbstractApplicationContext) context).close();
after triangle.draw();
Hope this will work..

[@Suraj-pf6ic]

Thanks for the reply. It finally worked for me. What I did was scraped the whole project and created a new one, it somehow worked.

[@SoeaOu]

EXCELENT tutorial, on pair with the newboston tutorials :)
best on YT

[@Anandpasunoori]

good one and liked the word 'big brother' :) 0,26

[@smalltiny]

Since XmlBeanFactory is deprecated, what should we use instead of that? Like, what replaced it?

[@Adonmasters]

+4surprisingly new ClassPathXmlApplicationContext("Spring.xml");

[@vitezkoja6949]

One of this:
BeanFactory context = new ClassPathXmlApplicationContext("spring.xml");
//or
ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");

[@abhishekmedha1098]

DefaultListableBeanFactory xbf = new DefaultListableBeanFactory();
XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(xbf);
reader.loadBeanDefinitions(new FileSystemResource("spring.xml"));
Triangle triangle=(Triangle)xbf.getBean("triangle");
triangle.draw();

[@HH_Linkmusic]

couldn't see what's the benefit of not using constructor directly

[@HeavilyWise]

Sir what happens if we don't create a package then what we will configure in class in spring. Xml

[@ahilachockalingam3840]

if draw method has arguments means then how can we call it on drawing app through spring

[@mandarbhosale7]

U told tht trianle is simple object so it doesnt matter tht much to use spring.xml for this but can u give us an example of real time complex object for which using spring.xml is really beneficial?

[@amaraghoufa]

Excellent tutorial thanks

[@kzanonymscatalyst2196]

If constructor initialization fails with illegalargumentexception (like that) check your spring version and JRE version.... I used spring 3.0.5 and JRE 1.8 and got this error.... I changed JRE to 1.6 and it worked fine for me.

[@sebon11]

Nice dude

[@heerendra9056]

Dude its showing error that jar is no source attachment? what i have to do?

[@05deeps]

you are using triangle object where did polymorphism go?

[@sakshamapuri88]

can we use any other access modifier for triangle member ? ,

[@linagsph]

Just make sure your spring.xml is closed when you are running the application.

[@ilahinadaf3666]

nice tutorial

[@0x28]

Not always true about being much more competent.. the problem is that they don't share the information and that they are not nice about it.. they are the 'google-it' types. Unfortunately that's how higher education is. The professor will not tell you how things are.. you have to decide what they are and if what you think is the answer.. is a valid one. I followed all the tutorials of koushik and thenewboston.. but professors always ask for more difficult concepts than that.. much harder.

[@pnbalaji]

Thanks for the tutorial. I just started watching this and it is really great. I do have a question though. If I want two instances of the Triangle class with one as type = equilateral and one as type = isoceles, how do I do? The spring xml has only one definition for the bean "triangle". Please help me understand.

[@bumblebee7370]

I know its been too late! you can set two bean configuration in the spring.xml file. One with the equilateral property and the other with the isosceles. Similarly, you can set two different IDs to extract the bean. Hope this helps!.

[@ArunKumar-ut4rq]

​@@bumblebee7370 of course didn't him but helped me dude.

[@12345678330ful]

It is giving me error that getBean() method not present in ApplicationContext please help

[@k-dari-23]

+Aniket Maryapgol Maybe the xml parameter that you have insert does not see the original because you typed wrong the name , or is not in default directory (src/main/resources)... If the xml is not in the default place you must write the path...

[@codingiscreativity]

In main() if I access triangle.getType() it does not show any result but if I try; triangle.draw() then it shows result from getType().....does anyone knows why direct calling of getType() doesn't give result on console?

[@wakkawalla]

+Sharmistha Sakar
Assuming you have copied the code from the video the same way i did:
Calling triangle.getType() from main() does not output anything on the console because getType() actually returns a String value and does not call System.out.println() whereas draw() does.

[@vitezkoja6949]

Thank you on answer, I was wondering why that dont work, now I know ;) :)

[@anatoliistepaniuk8217]

Got a problem here - maven can't find my spring.xml file. I've tried to put in everywhere! Where it should be placed?

[@johnlestermercado20]

+Anatolii Stepaniuk I also had this problem. Try creating the XML file inside src. You will notice that it will also be copied inside the bin folder. I hope it works.

[@rogernkosi8420]

ApplicationContext cpontext = new ClassPathXmlApplicationContext("file:src/main/resources/spring.xml");

[@suneethadevi4257]

create your xml file in your source folder

[@elalamiomar8139]

put it under src/main/java folder

[@Yousuf58967]

code is not visible well, plz try o zoom in

[@pnkjshrm30]

Hey..Your tutorial is great. Very well explained.
The variable 'type' that you defined has a private access in your code but if I define it as private my code shows an Error
Error: A JNI error has occurred, please check your installation and try again
Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/c
ore/io/Resource
If I declare it to be Public.. then it works fine..
Can you plz explain ??

[@psykoblast]

you are my Lord ! thank you ! plz increaze rezolution ;)

[@palkadm]

great tutorial although you can sometimes use ctrl+space or ctrl+shift+o :)

[@AjayKumar-fd9mv]

Great👍

[@gowanrohit4296]

siraaaa

[@mirnafayezboules3310]

those getting such error "Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [****.xml]; "
can follow this it may help :
he just added the package in the directory to be : "org/kou***/javabrains/spring.xml" instead of "spring.xml"
stackoverflow.com/questions/19651080/exception-in-thread-main-org-springframework-beans-factory-beandefinitionstore

[@thrinadhvenkata2315]

how to initialize properties

[@jasonl412]

when you run main method, this line of code: ApplicationContext context = new Class,PathXMLApplicationContext("spring.xml"), then the spring container will do the following things:
1,scan the class path to find a file named "spring.xml", spring will find it.
2,spring will parse the xml file in specific rule like beans, bean, property
3,use java reflection to create a bean, and set id as "triangle"
4,use setMethod to set class variable type
5,store the bean and waiting for use.

[@llitfkitfk]

Watching in 2020

[@shreerangakv7183]

what OS is that ?

[@dusanjovanov]

shreeranga kv its linux fedora i think

[@jasonl412]

Linux, maybe Ubuntu

[@manojrao9867]

Awesome

[@AHTOIIIKA]

Спасибо!

[@botrate412]

getting null for getType()

[@botrate412]

my mistake accidently made changes in spring.xml which is outside the src ..hence I was getting null since there was no property tag in spring.xml which is inside src

[@kayyanist]

subtitles are disastrous mate. what the hell are they ??! o_0

[@Rioisthep134]

Wow😂