Spring CustomEditorConfigurer Example using spring 4
In this article, I will discuss Spring CustomEditor.
While coding often there is a requirement where you want Text value will automatically convert into a desired Datatype and Vice versa.
Think about Struts ActionForm Or Spring @PathParam , @Formparam
Where parameters value in the request are String but in ActionForm you get it desired Type say Integer, Date etc.
@Path(“employee”)
@RequestParam({age})
Say doX(@Pathparam(“age”)Integer age){….}
In above code snippet age automatically convert String to an integer. But How it is possible?
The Answer is java Bean’s PropertyEditor interface by implementing PropertyEditor you can convert a string to your Custom datatype and Vice versa . To do that you have to implement its two main methods
public void setAsText(String text) and public String getAsText().
In Spring We can do it through Spring Built-in Custom editor. Or you can create your Own Editor by extending Java Beans PropertyEditorSupport Class which implements PropertyEditor interface.
Problem statement: In Spring Suppose I want when an employee gives his Address in String format that will automatic convert to Address Class and from Address it will Extract zip-code and State.
To solve this problem, I need to implement a CustomEditor class which will take the String convert it into Address Object and do the extract operation.
I assume “-“ is the separator when the employee provides address in String format .
Apart from that, I need to register this custom Editor in Spring application Context so before any bean initialization it should be initialized so that, for any bean where a conversion needed from String to Address Object, this Custom Editor will be invoked by Spring container.
We do this by creating a Custom Register which extends Spring PropertyEditorRegistrar class and register our Custom Editor.
Step 1 : create Address Object and provide the logic to extract zip and state from string provided by Employee
package com.example.aware;
public class Address {
String adress;
String pin;
String state;
Address() {
}
Address(String text) {
init(text);
}
private void init(String text) {
String[] arr = text.split("-");
this.setAdress(arr[0]);
this.setPin(arr[1]);
this.setState(arr[2]);
}
public String getAdress() {
return adress;
}
public void setAdress(String adress) {
this.adress = adress;
}
public String getPin() {
return pin;
}
public void setPin(String pin) {
this.pin = pin;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
@Override
public String toString() {
return "Address [adress=" + adress + ", pin=" + pin + ", state="
+ state + "]";
}
}
Step 2 : Create an Employee bean
package com.example.aware;
import java.util.Date;
public class Employee {
private Integer id;
private String firstName;
private String lastName;
private String designation;
private Address address;
//Setters and Getters
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
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 String getDesignation() {
return designation;
}
public void setDesignation(String designation) {
this.designation = designation;
}
public Address getAddress() {
return address;
}
public void setAddress(Address address) {
this.address = address;
}
@Override
public String toString() {
return "Employee [id=" + id + ", firstName=" + firstName
+ ", lastName=" + lastName + ", designation=" + designation
+ ", address=" + address + "]";
}
}
Observe address type is Address not String but from spring bean XML I pass String value that automatically converted to Address Object
Step 3: Create Custom editor which will convert String to Address Object
package com.example.aware;
import java.beans.PropertyEditorSupport;
public class CustomAddressEditor extends PropertyEditorSupport{
public void setAsText(String text) {
setValue(new Address(text.toUpperCase()));
}
}
Look in setAsText I pass Address Object and pass text value as the constructor argument ,setvalue is the method which inherits from PropertyEditorSupport, it set the value to the bean , so here from String to Address conversion is done.
Step 4: Register this bean into Spring Container so it can initialize before any beam. It acts as Bean post processor
package com.example.aware;
import java.util.Date;
import org.springframework.beans.PropertyEditorRegistrar;
import org.springframework.beans.PropertyEditorRegistry;
import org.springframework.beans.propertyeditors.ClassEditor;
import org.springframework.beans.propertyeditors.StringArrayPropertyEditor;
public class CustomAddressEditorRegistrar implements PropertyEditorRegistrar {
@Override
public void registerCustomEditors(PropertyEditorRegistry registry) {
registry.registerCustomEditor(Address.class, new CustomAddressEditor());
}
}
Here I register CustomAddressEditor.
Step 5: Spring Bean XML declaration
<?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 class="org.springframework.beans.factory.config.CustomEditorConfigurer">
<property name="propertyEditorRegistrars">
<list>
<bean class="com.example.aware.CustomAddressEditorRegistrar"/>
</list>
</property>
</bean>
<!-- employee bean -->
<bean id="employee" class="com.example.aware.Employee">
<property name="firstName" value="Shamik"/>
<property name="lastName" value="Mitra"/>
<property name="designation" value="Tech Lead"/>
<property name="address" value="1,NiveditaLane-700003-westbengal"/>
</bean>
</beans>
Step 6 : Test the application
package com.example.aware;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Main {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("configFiles/customEditor.xml");
Employee employee = (Employee) context.getBean("employee");
System.out.println(employee);
}
}
Output :
Employee [id=null, firstName=Shamik, lastName=Mitra, designation=Tech Lead, address=Address [adress=1,NIVEDITALANE, pin=700003, state=WESTBENGAL]]
Please note that in Spring there is many inbuilt CustomEditor try to use them. If your problem statement not matching with any of built-in editor then only create your own custom Editor.
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