spring-Dependency Injection based on constructors

Spring constructor-based dependency injection

When a container invokes a class constructor with a set of parameters, the constructor-based di is completed, where each parameter represents a dependency on another class.

Contents of the Texteditor.java file:

 Package Com.tuorialsponit;  Public class texteditor {    private  spellchecker spellchecker;      Public TextEditor (spellchecker spellchecker) {        this. Spellchecker= spellchecker;    }         publicvoid  spellcheck () {        spellchecker.checkspelling ();    }}

The following is another dependent class file Spellchecker.java content

 Package Com.tuorialsponit;  Public class spellchecker {    public  spellchecker () {        System.out.println ("Inside spellchecker constructor. " );    }          Public void checkspelling () {        System.out.println ("Inside checkspelling.") );    }}

The following is the contents of the Mainapp.java file

 Public class Mainapp {    publicstaticvoid  main (string[] args) {        new Classpathxmlapplicationcontext ("Beans.xml"); //            TextEditor TextEditor = (texteditor) context.getbean ("TextEditor");        Texteditor.spellcheck ();    }}

The following is the content of the configuration file Beans.xml, which has a configuration based on constructor injection:

<BeanID= "TextEditor"class= "Com.tuorialsponit.TextEditor">         <Constructor-argref= "Spellchecker"></Constructor-arg>     </Bean>          <BeanID= "Spellchecker"class= "Com.tuorialsponit.SpellChecker">     </Bean>

Operation Result:

spring-Dependency Injection based on constructors