Monday, August 26, 2013

Constructor Injection with collections


Can inject collection values by constructor in Spring framework.
Can use with <constructor-arg>
1. list ( use list, set )


   <constructor-arg>
     <list>
       <value>94773020595</value>
       <value>94773020596</value>
       <value>94112613044</value>
     </list>
   </constructor-arg>

   <constructor-arg>
     <list>
        <ref bean="books1Bean"/>
        <ref bean="books2Bean"/>
        <ref bean="books3Bean"/>
        <ref bean="books4Bean"/>
     </list>
   </constructor-arg>
2. map

<constructor-arg>
   <map>
     <entry key="Sports Journal" value="TENs sport"> </entry>
     <entry key="Science" value="Gravity"></entry>
   </map>
</constructor-arg>

<constructor-arg>
   <map>
     <entry key-ref="newsPaper1Bean" value-ref="editor1Bean"></entry>
     <entry key-ref="newsPaper2Bean" value-ref="editor2Bean"></entry>
   </map>
</constructor-arg>

Find the example below.
Steps as follows:
      1. Create Books, Editor, NewsPaper, & Author java classes
      2. Create ApplicationContext emaple
      3. Create executable class called DisplayAuthorInformation.java
1. Create Books.java
package com;
import java.io.Serializable;
public class Books implements Serializable {

/**
*
*/
   private static final long serialVersionUID = 1L;
   private int bookRefId;
   private String bookCategory;
   private String bookName;
   private String publishedYear;
   
   Books(int refId, String category, String name, String year){
     super();
     this.bookRefId = refId;
     this.bookCategory = category;
     this.bookName = name;
     this.publishedYear = year;
   }

   public String displayBookDetails(){
     return "Reference ID : " + bookRefId + "\n\tCategory : " + bookCategory + "\n\tBook Name : " + bookName + "\n\tPublished Year : " + publishedYear;
   }

}
2. Create Editor.java
package com;

import java.io.Serializable;
public class Editor implements Serializable {

/**
*
*/
   private static final long serialVersionUID = 1L;
   private String editorRefId;
   private String editorName;
    
   public Editor(String editorRefId, String editorName) {
     super();
     this.editorRefId = editorRefId;
     this.editorName = editorName;
   }

   public String diplayEditor(){
     return "\n\tEditor Reference ID : " + editorRefId+ "\n\tEditor Name : " + editorName;
   }

}
3. Create NewsPaper.java
package com;

import java.io.Serializable;
public class NewsPaper implements Serializable {

/**
*
*/
   private static final long serialVersionUID = 1L;
   private String refID;
   private String paperName;
   private String day;

   public NewsPaper(String refID, String paperName, String day) {
    super();
    this.refID = refID;
    this.paperName = paperName;
    this.day = day;
   }

   public String diplayNewsPaper(){
     return "\tReference ID : " + refID + "\n\tPaper Name : " + paperName + "\n\tPublish Day : " + day;
   }

}

4. Create Author.java
package com;

import java.io.Serializable;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
public class Author implements Serializable {

/**
*
*/
   private static final long serialVersionUID = 1L;
   private String autherName;
   private List<String> contactInfo;
   private List<Books> bookList;
   private Map<String, String> journalsDetails;
   private Map<NewsPaper, Editor> papers;
  
   public Author(String aName, List<String> contactInfo, List<Books> bookList,
Map<String, String> journalsDetails, Map<NewsPaper, Editor> papers) {
     super();
     this.autherName = aName;
     this.contactInfo = contactInfo;
     this.bookList = bookList;
     this.journalsDetails = journalsDetails;
     this.papers = papers;
   }

   void displayAuthorDetails(){
     System.out.println("Author Name : " + autherName);

     System.out.println("\nContacts - ");    
     Iterator<String> itrContactList = contactInfo.iterator();
     while(itrContactList.hasNext()){
       System.out.println(" * " + itrContactList.next());
     }

     System.out.println("\nBooks - ");
     Iterator<Books> itrBookList = bookList.iterator();
     while(itrBookList.hasNext()){
       System.out.println("\t" + itrBookList.next().displayBookDetails() + "\n");
     }

     System.out.println("Journals - ");
     Set<Entry<String, String>> set = journalsDetails.entrySet();
     Iterator<Entry<String, String>> itrJournals = set.iterator();
     while(itrJournals.hasNext()){
       Entry<String, String> entry = itrJournals.next();
       System.out.println(" * " + entry.getKey() + " - " + entry.getValue());
     }

     System.out.println("\nPapers - ");
     Set<Entry<NewsPaper, Editor>> setPaper = papers.entrySet();
     Iterator<Entry<NewsPaper, Editor>> itrPaper = setPaper.iterator();
     while(itrPaper.hasNext()){
        Entry<NewsPaper, Editor> entry = itrPaper.next();
        NewsPaper newsPaper = entry.getKey();
        Editor editor = entry.getValue();
        System.out.println("\n* " + newsPaper.diplayNewsPaper() + "\n---\n " +    editor.diplayEditor());
     }
   }
}

 
5. Create ApplicationContext.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">
<bean id="books1Bean" class="com.Books">
  <constructor-arg type="int" value="100103"></constructor-arg>
  <constructor-arg value="Programming"></constructor-arg>
  <constructor-arg value="Spring for every one"></constructor-arg>
  <constructor-arg value="2010"></constructor-arg>
</bean>
<bean id="books2Bean" class="com.Books">
  <constructor-arg type="int" value="100102"></constructor-arg>
  <constructor-arg value="Programming"></constructor-arg>
  <constructor-arg value="Struts 2"></constructor-arg>
  <constructor-arg value="2008"></constructor-arg>
</bean>

<bean id="books3Bean" class="com.Books">
  <constructor-arg type="int" value="100101"></constructor-arg>
  <constructor-arg value="Programming"></constructor-arg>
  <constructor-arg value="Hibernate"></constructor-arg>
  <constructor-arg value="2008"></constructor-arg>
</bean>
 
<bean id="books4Bean" class="com.Books">
  <constructor-arg type="int" value="100100"> </constructor-arg>
  <constructor-arg value="Network"></constructor-arg>
  <constructor-arg value="TCP/IP"></constructor-arg>
  <constructor-arg value="2009"></constructor-arg>
</bean>
 
<bean id="newsPaper1Bean" class="com.NewsPaper">
  <constructor-arg value="NP001"></constructor-arg>
  <constructor-arg value="Sunday Observer"></constructor-arg>
  <constructor-arg value="Sunday"></constructor-arg>
</bean>

<bean id="newsPaper2Bean" class="com.NewsPaper">
  <constructor-arg value="NP002"></constructor-arg>
  <constructor-arg value="Times"></constructor-arg>
  <constructor-arg value="Monday"></constructor-arg>
</bean>

<bean id="editor1Bean" class="com.Editor">
  <constructor-arg value="ED0001"></constructor-arg>
  <constructor-arg value="Sandamali Silva"></constructor-arg>
</bean>
<bean id="editor2Bean" class="com.Editor">
  <constructor-arg value="ED0002"></constructor-arg>
  <constructor-arg value="Thinuli Pathirana"></constructor-arg>
</bean>
 
<bean id="authorBean" class="com.Author">

  <constructor-arg value="Sanjeeva Pathirana"></constructor-arg>
  <constructor-arg>
    <list>
      <value>94773020595</value>
      <value>94773020596</value>
      <value>94112613044</value>
    </list>
  </constructor-arg>
  <constructor-arg>
    <list>
       <ref bean="books1Bean"/>
       <ref bean="books2Bean"/>
       <ref bean="books3Bean"/>
       <ref bean="books4Bean"/>
    </list>
  </constructor-arg>

  <constructor-arg>
     <map>
        <entry key="Sports Journal" value="TENs sport"></entry>
        <entry key="Science" value="Gravity"></entry>
     </map>
  </constructor-arg>
   
  <constructor-arg>
     <map>
        <entry key-ref="newsPaper1Bean" value-ref="editor1Bean"></entry>
        <entry key-ref="newsPaper2Bean" value-ref="editor2Bean"></entry>
     </map>
   </constructor-arg>

</bean>
</beans>


6. Create DisplayAuthorInformation.java


package com;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
public class DisplayAuthorInformation {
/**
* @param args
*/
   public static void main(String[] args) {
     DisplayAuthorInformation authorInformation = new    DisplayAuthorInformation();
     authorInformation.doExecute();
   }
   private void doExecute(){
     Resource resource = new ClassPathResource("xml/ApplicationContext.xml");
     BeanFactory beanFactory = new XmlBeanFactory(resource);
     Author authorDetails = (Author)beanFactory.getBean("authorBean");
     authorDetails.displayAuthorDetails();
   }
}

Out put as follows:
Author Name : Sanjeeva Pathirana
Contacts -
* 94773020595
* 94773020596
* 94112613044
Books -
Reference ID : 100103
Category : Programming
Book Name : Spring for every one
Published Year : 2010
Reference ID : 100102
Category : Programming
Book Name : Struts 2
Published Year : 2008
Reference ID : 100101
Category : Programming
Book Name : Hibernate
Published Year : 2008
Reference ID : 100100
Category : Network
Book Name : TCP/IP
Published Year : 2009
Journals -
* Sports Journal - TENs sport
* Science - Gravity
Papers -

* Reference ID : NP001
Paper Name : Sunday Observer
Publish Day : Sunday
---
Editor Reference ID : ED0001
Editor Name : Sandamali Silva
* Reference ID : NP002
Paper Name : Times
Publish Day : Monday
---
Editor Reference ID : ED0002
Editor Name : Thinuli Pathirana




Posted by at
Labels: