Understanding Spring Container in Spring Framework

In previous tutorial of spring framework we have seen what dependency injection is and the usage of dependency injection. We have also seen the dependency object will be created and injected by Spring Container. In this tutorial we will what spring container is and the role of it in spring framework.

Understanding Spring Container or IOC Container

Spring Container is similar to Servlet Container, so if we understand the role of servlet container we will understand the Container as well.

Servlet Container

Servlet container will read configuration details (web.xml), instantiate the servlet object, pass the property values and manages the servlet life cycle starting from instantiation to destruction.

Spring Container

Similarly in Spring, Container will read configuration file, creates the object(s) and dependency object(s), inject the dependencies and manages the bean/pojo life cycles.

Spring Container or IOC Container in Spring

As mentioned in above figure Container will read xml file which contains configuration details about Pojo. Using Java Reflection, it will create dependency object along with all the required properties, also it will inject dependency object into our pojo classes.

In Spring, Container will read the configuration from xml file or through java annotation or by using Java Code. In our forthcoming tutorials we will see examples of each one.

Spring Container or IOC Container and its Types

Spring Container can also be specified as IOC container. IOC Container can be classified as two types

Core Container and
J2EE Container

Note:

We also have one more container in spring called Web Container.

Spring Core Container:

org.springframework.beans.factory.BeanFactory (Interface) implementation was provided by org.springframework.beans.factory.xml.XmlBeanFactory class.

J2EE Container:

org.springframework.context.ApplicationContext (Interface) extended by org.springframework.context.ConfigurableApplicationContext (Interface) and it’s has two important implementations i.e org.springframework.context.support.ClasspathXmlApplicationContext (class) and org.springframework.context.support.FileSystemXmlApplicationContext (class)

We also have other implementation like WebXmlApplicationContext and XmlWebApplicationContext which we will see in our future tutorials. We will also see in details about BeanFactory and ApplicationContext in the future details.

Please post your questions in the comment box, if you like this tutorial please share it with your friends.

Dependency Injection in Spring

Rod Johnson created Spring Framework. Spring framework is very famous for Dependency Injection. Before going to learn about Spring and its concepts, we will first understand what Dependency Injection in Spring is.

Related Spring Tutorials

How to Create Spring MVC application using Java Based Configuration

Generate Excel in Spring MVC Application using Apache POI

JQuery Datatable in Spring MVC Application

Advance Features of JQuery Datatable in Spring MVC Application

Dependency Injection in Spring

We all have Smart Phones, in which we must have Gallery Application. Let’s consider Gallery Application as a Class Gallery (Dependency Injection Figure 1.1).

Dependency Injection in Spring 1.1

We know in all Gallery Application we can send/share our photos/videos to others. In order to share photos/videos we will use some other application like WatsApp or Gmail. So Our Gallery Application having the dependency of WatsApp or Gmail (Dependency Injection Figure 1.2)

Dependency Injection in Spring 1.2

If we want to share photos using some other external application like Gmail, WeChat, etc then we have to create all the all the Other class instances inside Gallery (Fig 1.3). So instance of WatsApp, WeChat or Gmail inside Gallery class makes the Gallery class tight coupled.

Dependency Injection in Spring 1.3

Using Dependency Injection we can make the Gallery class as loosely coupled. In order to make Dependency Injection, first we have to make a Contract called Interface for All the External Application class i.e WatsApp, WeChat, Gmail. For the interface we have to create implementations as mentioned figure 1.4.

Dependency Injection in Spring – 1.4

In Gallary class instead of directly creating an instance of External Application class (WatApp, Gmail, WeChat), we have created it and assigned to Interface (SharingApp), this concept is called RunTime Polymorphishm (Fig 1.5). With the help of Run Time polymorphism we can pass the SharingApp instance to any method which is of type SharingApp. The corresponding implementation will be executed at run time.

Dependency Injection in Spring – 1.5

But still our gallery class is still tightly coupled with External Application class, in order to eliminate the dependency of External Application in Gallery class, the External Application dependency has to be injected (passed) dynamically.

In order to inject dependency, we should have a setter/constructor which accepts our dependency as a parameter and assigned to our dependency variable.(Fig 1.6) So during run time we can pass our dependencies and inject it to our gallery class. In this way even if the external application grows (like FB Messenger, Hike etc), we can inject it to our gallery class dynamically.

Dependency Injection in Spring

Spring Container will take care of dependency creation and dependency injection, which we will see in fore coming tutorials.

To summarize, We have created an Interface/Abstract Class and kept it as member variable in class. We also provided a constructor or setter method which is of Interface type. During run time the corresponding implementation class will be instantiated and passed (injected) to setter/constructor, through which we have reduced the class from tightly coupled to loosely coupled.

How to Generate Excel in Spring MVC Application using Apache POI

In our earlier tutorial we have already seen How to Create Spring MVC application using Java Based Configuration. In this tutorial we will see some advance concepts of Spring MVC. In this tutorial we will see how to Generate Excel in Spring MVC Application using Apache POI.

How to Generate Excel in Spring MVC Application using Apache POI

I have already a created a tutorial of “How to Create Spring MVC application using Java Bsed Configuration”. This might help you in Creating a Spring Web Application. After creating a Spring MVC application we will be getting a project Structure like this. From that project structure we will add new files/code and generates excel using Spring MVC Application.

How to Generate Excel in Spring MVC Application using Apache POI – Project Structure

Getting Started – How to Generate Excel in Spring MVC Application using Apache POI

To generate Excel Document, we are going to use Apache Poi API. Lets add the below mentioned Dependency in pom.xml file.

<dependency>
      <groupId>org.apache.poi</groupId>
      <artifactId>poi</artifactId>
      <version>3.15</version>
 </dependency>

Java Change – How to Generate Excel in Spring MVC Application using Apache POI

Create a package and add a modal class into it. I have created Student class as mentioned below.

package com.learnfromexamples.springmvcjavaconfig.modal;

public class Student {
     private String studentId;
     private String studentName;
     private String studentMobileNum;
     
     public Student() {
          
     }
     public Student(String studentId, String studentName, String studentMobileNum) {
          super();
          this.studentId = studentId;
          this.studentName = studentName;
          this.studentMobileNum = studentMobileNum;
     }

     // getters and setters method
     //overriden toString() method
}

To build an Excel Document Spring provides an Abstract Class called “AbstractXlsView”. By Extending that, i have created a new class called “ExcelReportView” and overridden the buildExcelDocument() method. Inside that method we have provided our own implementation to build Excel Document.

package com.learnfromexamples.springmvcjavaconfig.view;

import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.springframework.web.servlet.view.document.AbstractXlsView;

import com.learnfromexamples.springmvcjavaconfig.modal.Student;


public class ExcelReportView extends AbstractXlsView{

 @Override
 protected void buildExcelDocument(Map<String, Object> model, Workbook workbook, HttpServletRequest request,
 HttpServletResponse response) throws Exception {
 
 response.setHeader("Content-Disposition", "attachment;filename=\"student.xls\"");
 List<Student> studentList = (List<Student>) model.get("studentList");
 Sheet sheet = workbook.createSheet("Student Data");
 Row header = sheet.createRow(0);
 header.createCell(0).setCellValue("Student ID");
 header.createCell(1).setCellValue("Student Name");
 header.createCell(2).setCellValue("Student Mobile");
 
 int rowNum = 1;
 for(Student student:studentList){
 Row row = sheet.createRow(rowNum++);
 row.createCell(0).setCellValue(student.getStudentId());
 row.createCell(1).setCellValue(student.getStudentName());
 row.createCell(2).setCellValue(student.getStudentMobileNum());
 }
 }
}

We already have a Controller for this project but for Segregation i have created a new one called “ReportController” with a method getExcel() which returns ModelAndView.

package com.learnfromexamples.springmvcjavaconfig.controller;

import java.util.ArrayList;
import java.util.List;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import com.learnfromexamples.springmvcjavaconfig.modal.Student;
import com.learnfromexamples.springmvcjavaconfig.view.ExcelReportView;

@Controller
@RequestMapping("/report")
public class ReportController {
       @RequestMapping(method=RequestMethod.GET)
       public ModelAndView getExcel(){
              List<Student> studentList = new ArrayList<Student>(); 
              studentList.add(new Student("S01", "Sri", "12344"));
              studentList.add(new Student("S02", "Dharan", "658"));
              return new ModelAndView(new ExcelReportView(), "studentList", studentList);
       }
}

Lets add hyperlink in welcome.jsp with a associated url to RequestMapping.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
 pageEncoding="ISO-8859-1"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>How to Generate Excel using Spring and Apache POI</title>
</head>
<body>
 <h1>Greeting : ${greetMsg}</h1>
 <spring:url value="/report" var="xlsURL"></spring:url>
 <a href="${xlsURL}">Excel Document</a>
</html>

Project Structure – Generate Excel in Spring MVC Application using Apache POI

Finally Our Project Structure will be like this.

How to Generate Excel in Spring MVC Application using Apache POI – Project Structure Final

Lets add the server and hit the URL. http://localhost:7171/SpringMVCJavaConfig/

How to Generate Excel in Spring MVC Application using Apache POI – Output

We will get Excel Document Like This

How to Generate Excel in Spring MVC Application using Apache POI – Output Excel

If you have any questions on Generate Excel in Spring MVC Application using Apache POI, please post your questions in Comment box. If you this tutorial please share it with your friends.

Advance Features of Jquery Datatable in Spring MVC with Example

Few months back we have seen one of the important jquery plugin called Jquery Datatable. Jquery Datatable provides many features like pagination, ordering, search etc. Although we have seen only some of its basic features. In this tutorial we are going to see advance features of jquery datatable in Spring MVC with example.

JQuery Datatable in Spring MVC with Example

Before going to see its advance features I recommend every one of you to know basic features of Jquery Datatable. In earlier tutorial we have created a Jquery Datatable application along with Spring MVC. This tutorial is a continuation of my previous Jquery Datatable tutorial, so we will be using same project structure and same files.

JQuery Datatable in Spring MVC with Example

Common.css

I have added few more styles for header, filters and for article tag in common.css

body{
 background-color: #eee;
}
img.dataTableExample{
 width:50%;
 padding-left: 25%;
}
div.dataTables_wrapper{
 padding-left:15%;padding-right:15%;
}
th {
 background-color: #4CAF50;
 color: white;
}
div.filters{
 background-color: ffffff;
 padding: 2%;
 
 color: #b72b21;
}
tr:nth-child(even) {background-color: #f2f2f2}
nav{
 width:20%;
 float: left;
}
ul{
 overflow-y: scroll;
 height: 200px;
 list-style-type: none;
}
h1{
 padding-left: 40%;padding-bottom: 10%;
}
h4{
 padding-left:40%;
}
article{
 width: 80%;
 float: right;
 border-left: 17%;
}

body.jsp

In body.jsp, i have added <header> tag, an empty <ul> tag and a submit <button> tag. Later using javascript code we are going to add <div> tags between <ul> tag.


<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<%@ page session="false" %>
<html>
<head>
 <title>JQuery Datatable + Spring MVC Example</title>
</head>
<body>

<div style="width: 100%;">

<header>

<h1>Spring MVC + JQuery Datatable</h1>

 </header>


<nav>

<h4>Employee Names</h4>


<ul>
 </ul>

 <button style="margin-left: 35%;">Submit</button>
 </nav>


<article>

<table id="example" class="display nowrap" cellspacing="0">

<thead>

<tr>

<th>Name</th>


<th>Desgination</th>


<th>Salary</th>


<th>Country</th>

 </tr>

 </thead>

 </table>

 </article>

 </div>

</body>
</html>

<script type="text/javascript">
$(document).ready(function(){
      var data =eval('${employeeList}');
      var table = $('#example').DataTable( {
                    "aaData": data,
                    "aoColumns": [
                        { "mData": "name"},
                        { "mData": "desgination"},
                        { "mData": "salary"},
                        { "mData": "country"} 
                    ],
                   "columnDefs": [ 
                        { 
                           "render" : function(data, type, row) {
                            return "<a class='empId' value="+data+" href=#>" + data + "</a>";
                            
                        },
                   "targets" : 0
                   },
                 ],
                   "paging" : true,
                   "pageLength" : 5,
                    "ordering" : true,
     });
           getFilters(table.column(0).data().unique());
           $('a.empID').click(function(e){
                 var employeeInfo = table.row($(this).parents('tr')).data();
                 alert("Employee Details \n\n\n Employee Name is :" + employeeInfo['name'] +"\n Employee Designation is: "+ employeeInfo['desgination'] +" \n Employee Salary is : "+employeeInfo['salary'] );
           });
         $('button').on('click',function(e){
                if($('input[type="checkbox"]:checked').length&amp;amp;amp;lt;1){
                alert('Select atlease one employee');
         }else{
                 var employeeNames = $('input[type="checkbox"]:checked').map(function(){
                 return this.value;
              }).get();
         var employeeRegex = "";
         $.each(employeeNames,function(key,value){
               if(key!=employeeNames.length-1){
               employeeRegex+=value+"|";
         }else{
             employeeRegex+=value;
         }
     });
      $('#example').DataTable().search(employeeRegex,true,false).draw();
  }
 });
});

function getFilters(empName){
 $.each(empName,function(key,value){
 $('ul').append('
<div class="filters">
<li><input class="empName" type="checkbox" value="'+value+'">'+value+'</li>
</div>

');
 });

JQuery Datatable in Spring MVC with Example

JQuery Datatable provides lots of advance features and now we will see some of the features of JQuery Datatable in Spring MVC with Example.

JQuery Datatable Options

columnDefs: columnDefs option will be used if we want to do any manipulation in any of the table row/column.

render: In render option we have to write the actual DOM manipulation.

targets: Using target option we will specify the column where we are doing the manipulation.

JQuery Datatable in Spring MVC with Example

var table = $('#example').DataTable( {
 "aaData": data,
 "aoColumns": [
 { "mData": "name"},
 { "mData": "desgination"},
 { "mData": "salary"},
 { "mData": "country"} 
 ],
 "columnDefs": [ 
 { 
 "render" : function(data, type, row) {
 return "&amp;amp;amp;lt;a class='empId' value="+data+" href=#&amp;amp;amp;gt;" + data + "&amp;amp;amp;lt;/a&amp;amp;amp;gt;";
 },
 "targets" : 0
 },
 ],
 "paging" : true,
 "pageLength" : 5,
 "ordering" : true,
 });

Methods in jQuery Datatable

jQuery Datatable also provide lot of methods, we will see few of the methods in JQuery Datatable in Spring MVC with Example.

row: row method will be used if we want to get any of the row information or if we want to work with any of the row information.

data: data method is used to get values of any of the row(s) or column(s)

JQuery Datatable in Spring MVC with Example – Method – Unique


$('a.empID').click(function(e){
var employeeInfo = table.row($(this).parents('tr')).data();
alert("Employee Details \n\n\n Employee Name is :" + employeeInfo['name'] +"\n Employee Designation is: "+ employeeInfo['desgination'] +" \n Employee Salary is : "+employeeInfo['salary'] );
});

search: Search method used to filter the datatable based on the filters parameter passed as a parameter. And we want to search for more than one filter, then we have to append the filter value with “|” and pass as a filter parameter.

JQuery Datatable in Spring MVC with Example – Method – Search


$('button').on('click',function(e){
if($('input[type="checkbox"]:checked').length&amp;amp;amp;amp;amp;lt;1){
alert('Select atlease one employee');
}else{
var employeeNames = $('input[type="checkbox"]:checked').map(function(){
return this.value;
}).get();
var employeeRegex = "";
$.each(employeeNames,function(key,value){
if(key!=employeeNames.length-1){
employeeRegex+=value+"|";
}else{
employeeRegex+=value;
}
});
$('#example').DataTable().search(employeeRegex,true,false).draw();
}
});

In our example, when we select the checkboxes and click on submit button. Then we pass those values as a parameter to search method and datatable will be filtered.

Now we have seen some more features of jQuery datatable in Spring MVC with Example. If you want to discuss about some other features of datatable, please mention it in comment box and i will try to provide one more tutorial along with those features.

If you have any queries in this jQuery datatable in Spring MVC with Example tutorial please comment your queries below and if you like this tutorial please share it with your friends and colleagues.

Click below download link to get jQuery datatable in Spring MVC with Example.

JQuery Datatable in Spring MVC with Example

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Learn from Examples

Tag Archives: Spring

Understanding Spring Container in Spring Framework

Servlet Container

Spring Container

Spring Container or IOC Container and its Types

Spring Core Container:

J2EE Container:

Dependency Injection in Spring

Dependency Injection in Spring

How to Generate Excel in Spring MVC Application using Apache POI

Getting Started – How to Generate Excel in Spring MVC Application using Apache POI

Java Change – How to Generate Excel in Spring MVC Application using Apache POI

Project Structure – Generate Excel in Spring MVC Application using Apache POI

Advance Features of Jquery Datatable in Spring MVC with Example

JQuery Datatable in Spring MVC with Example

JQuery Datatable Options

Methods in jQuery Datatable