JAVA EXAMPLE PROGRAMS

JAVA EXAMPLE PROGRAMS

Publish Your Article Here

How to use collections with spring expression language?


This page shows how to use collection objects along with spring expression language. Below example shows how to use list and map objects with spring expression language.

package com.java2novice.beans;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component("myCompanyBean")
public class MyCompany {

	private List<Employee> empList;
	private Map<String, Integer> empIdMap;
	
	@Value("#{myCompanyBean.empList[0]}")
	private Employee firstEmployee;
	
	@Value("#{myCompanyBean.empIdMap['Nataraja Gootooru']}")
	private int starEmpId;
	
	public MyCompany(){
		//populate list
		empList = new ArrayList<Employee>();
		empList.add(new Employee(1016, "Nataraja Gootooru"));
		empList.add(new Employee(1015, "Nagesh Yenamala"));
		empList.add(new Employee(1017, "Nikesh Penumalli"));
		//populate map
		empIdMap = new HashMap<String, Integer>();
		empIdMap.put("Nataraja Gootooru", 1016);
		empIdMap.put("Nagesh Yenamala", 1015);
		empIdMap.put("Nikesh Penumalli", 1017);
	}

	public void printEmpInfo(){
		System.out.println(this.firstEmployee.toString());
		System.out.println("Star employee id: "+this.starEmpId);
	}
	
	public List<Employee> getEmpList() {
		return empList;
	}

	public void setEmpList(List<Employee> empList) {
		this.empList = empList;
	}

	public Map<String, Integer> getEmpIdMap() {
		return empIdMap;
	}

	public void setEmpIdMap(Map<String, Integer> empIdMap) {
		this.empIdMap = empIdMap;
	}

	public Employee getFirstEmployee() {
		return firstEmployee;
	}

	public void setFirstEmployee(Employee firstEmployee) {
		this.firstEmployee = firstEmployee;
	}

	public int getStarEmpId() {
		return starEmpId;
	}

	public void setStarEmpId(int starEmpId) {
		this.starEmpId = starEmpId;
	}
}

package com.java2novice.beans;

public class Employee {

	private int empId;
	private String name;
	
	public Employee(int id, String name){
		this.empId = id;
		this.name = name;
	}
	
	public int getEmpId() {
		return empId;
	}
	public void setEmpId(int empId) {
		this.empId = empId;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}

	@Override
	public String toString(){
		return this.empId+" | "+this.name;
	}
	
}

Here is the xml based configuration, you must enable component scan.

<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans
	http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
	http://www.springframework.org/schema/context
	http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <context:component-scan base-package="com.java2novice.beans" />
</beans>

Spring bean demo class:

package com.java2novice.test;

import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.java2novice.beans.MyCompany;

public class SpringDemo {

	public static void main(String a[]){
		String confFile = "applicationContext.xml";
		ConfigurableApplicationContext context 
							= new ClassPathXmlApplicationContext(confFile);
		MyCompany myCompany = (MyCompany) context.getBean("myCompanyBean");
		myCompany.printEmpInfo();
	}
}

Output:
1016 | Nataraja Gootooru
Star employee id: 1016
<< Previous Program | Next Program >>
blog comments powered by Disqus

Spring framework examples

  1. Spring 3 hello world example
  2. Spring bean java based configuration using @Configuration and @Bean
  3. How to get spring application context object reference?
  4. How to load multiple spring bean configuration files?
  5. Spring java based configuration @Import example
  6. Spring Dependency Injection and Types
  7. Spring Dependency Injection via setter method
  8. Spring Dependency Injection via Constructor
  9. Constructor overloading issue with spring constructor injection
  10. Constructor vs Setter dependency Injection in Spring
  11. How to inject value into spring bean instance variables?
  12. Spring bean tag properties
  13. Differen types of spring bean scopes
  14. How to inject inner bean in spring?
  15. Set spring bean scope using annotation
  16. How to invoke spring bean init and destroy methods?
  17. Spring bean initialization callback
  18. Spring bean destruction callback
  19. Configure default initialization and destroy method in all spring beans
  20. Spring bean init and destroy methods using annotations
  21. Spring Bean Post Processors
  22. How to read property file in spring using xml based configuration file?
  23. How to read property file in spring 3.0 using java based configuration?
  24. How to inject date into spring bean property?
  25. How to inject date into spring bean with CustomDateEditor?
  26. Spring bean inheritance configuration
  27. Spring dependency checking with @Required annotation
  28. How to define a custom Required-style annotation for dependency checking?
  29. How to inject List into spring bean?
  30. How to inject Set into spring bean?
  31. How to inject Map into spring bean?
  32. How to enable auto component scanning in spring?
  33. Difference between @Component, @Service, @Repository and @Controller
  34. How to filter components in auto scanning?
  35. Spring expression language basic example using xml based configuration.
  36. Spring expression language basic example using annotations.
  37. Bean reference example using spring expression language
  38. Spring expression language operators example
  39. Spring expression language ternary operator example
  40. How to use regular expressions with spring expression language?
  41. How to use collections with spring expression language?
  42. Spring bean auto-wiring modes
  43. Spring auto-wiring mode byName
  44. Spring auto-wiring mode byType
  45. Spring auto-wiring mode constructor
  46. Spring auto-wiring using @Autowired annotation example
  47. Spring auto-wiring using @Qualifier annotation example
  48. Spring log4j configuration
  49. How to schedule jobs using @Scheduled annotation in spring?
  50. Send E-mail using spring 3
  51. Send E-mail with attachment using spring 3
  52. Simple spring JDBC example
  53. Spring JDBC example with JdbcTemplate
  54. Spring JDBC example with JdbcDaoSupport
  55. Spring JDBC query example using JdbcDaoSupport
  56. How to query single column using spring JdbcTemplate?
  57. Spring JDBC batch updates using JdbcTemplate?
  58. Spring AOP Advices - Before advice example - xml based configuration
  59. Spring AOP Advices - After returning advice example - xml based configuration
  60. Spring AOP Advices - After throwing advice example - xml based configuration
  61. Spring AOP Advices - Around advice example - xml based configuration
  62. Spring AOP Advice - Pointcuts – Name match example
  63. Spring AOP Advice - Pointcuts – Regular expression example
  64. Spring AOP - AspectJ - @Before example
  65. Spring AOP - AspectJ - @After example
  66. Spring AOP - AspectJ - @AfterReturning example
  67. Spring AOP - AspectJ - @AfterThrowing example
  68. Spring AOP - AspectJ - @Around example
Knowledge Centre
Class, Constructor and Primitive data types
Class is a template for multiple objects with similar features and it is a blue print for objects. It defines a type of object according to the data the object can hold and the operations the object can perform. Constructor is a special kind of method that determines how an object is initialized when created. Primitive data types are 8 types and they are: byte, short, int, long, float, double, boolean, char.
Famous Quotations
The greatest obstacle to discovery is not ignorance; it is the illusion of knowledge.
-- Daniel J. Boorstin

About Author

Most Visited Pages

Other Interesting Sites

Reference: Java™ Platform Standard Ed. 7 - API Specification | Java is registered trademark of Oracle.
Privacy Policy | Copyright © 2017 by Nataraja Gootooru. All Rights Reserved.