In this
post, i am going to explain, how to inject one object into other object. This
post explains you, how to inject “Address” object into “Employee” object step
by step.
Step 1
: Create new
maven project “spring_tuorial”. Project structure looks like below.
Step 2
: Update
“pom.xml” file for maven dependencies.
pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>spring_tutorial</groupId> <artifactId>spring_tutorial</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>war</packaging> <name>spring_tutorial</name> <description>spring_tutorial</description> <properties> <org.springframework-version>4.1.5.RELEASE</org.springframework-version> </properties> <dependencies> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${org.springframework-version}</version> </dependency> </dependencies> </project>
Step
3: Create new
package “com.springtutorial.model” under “src/main/java”.
Step
4: Create
“Address” class under the package “com.springtutorial.model”.
package com.springtutorial.model; public class Address { private String street; private String city; private String state; private String country; private String pin; public String getStreet() { return street; } public void setStreet(String street) { this.street = street; } public String getCity() { return city; } public void setCity(String city) { this.city = city; } public String getState() { return state; } public void setState(String state) { this.state = state; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } public String getPin() { return pin; } public void setPin(String pin) { this.pin = pin; } @Override public String toString() { StringBuilder builder = new StringBuilder(); builder.append("Address [street=").append(street).append(", city=").append(city) .append(", state=").append(state).append(", country=").append(country).append(", pin=") .append(pin).append("]"); return builder.toString(); } }
Step
5: Create
“Employee” class under the package “com.springtutorial.model”.
package com.springtutorial.model; public class Employee { private String firstName; private String lastName; private int id; private Address address; public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public int getId() { return id; } public void setId(int id) { this.id = id; } public Address getAddress() { return address; } public void setAddress(Address address) { this.address = address; } @Override public String toString() { StringBuilder builder = new StringBuilder(); builder.append("Employee [firstName=").append(firstName).append(", lastName=").append(lastName) .append(", id=").append(id).append(", address=").append(address).append("]"); return builder.toString(); } }
Step
6: Create
“spring.xml” file in “src/main/resources”.
spring.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="employee1" class="com.springtutorial.model.Employee"> <property name="firstName" value="Hari Krishna" /> <property name="lastName" value="Gurram" /> <property name="id" value="553" /> <property name="address" ref="address1" /> </bean> <bean id="address1" class="com.springtutorial.model.Address"> <property name="street" value="Chowdeswari temple" /> <property name="city" value="Bangalore" /> <property name="state" value="Karnataka" /> <property name="country" value="India" /> <property name="pin" value="560037" /> </bean> </beans>
"spring.xml"
is used to assign unique IDs to different beans, to control the creation of
objects with different values.
<bean id="address1"
class="com.springtutorial.model.Address">
<property
name="street" value="Chowdeswari temple" />
<property
name="city" value="Bangalore" />
<property
name="state" value="Karnataka" />
<property
name="country" value="India" />
<property
name="pin" value="560037" />
</bean>
Above
statement create Address instance.
<property
name="address" ref="address1" />
Above
statement assigns the bean with id “address1” to the propery “address” .
You have
to make sure that “spring.xml” file is available in CLASSPATH and use the same
name in main application while creating application context as shown in
Main.java file.
Step 7
: Create package
“com.springtutorial.main” under “src/main/java”.
Step 8
: Create Main
class under package “com.springtutorial.main”.
package com.springtutorial.main; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import com.springtutorial.model.Employee; public class Main { public static void main(String args[]) { ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml"); Employee emp1 = (Employee) context.getBean("employee1"); System.out.println(emp1); } }
Step 9
: Run
Main.java,you will get output like below.
Mar 22, 2015 9:21:04 PM org.springframework.context.support.ClassPathXmlApplicationContext prepareRefresh INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1873a6: startup date [Sun Mar 22 21:21:04 IST 2015]; root of context hierarchy Mar 22, 2015 9:21:04 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions INFO: Loading XML bean definitions from class path resource [spring.xml] Employee [firstName=Hari Krishna, lastName=Gurram, id=553, address=Address [street=Chowdeswari temple, city=Bangalore, state=Karnataka, country=India, pin=560037]]
No comments:
Post a Comment