choose between SOAP and REST
Choosing between SOAP and REST web services depends on the requirements and constraints of your application. Both have their advantages and disadvantages, making them suitable for different scenarios.

Table of Contents
SOAP (Simple Object Access Protocol)
Advantages :
- 1. Â Formal Contracts : Uses WSDL (Web Services Description Language) to define service interfaces, ensuring strict contracts.
- 2. Â Extensibility : Supports various protocols and standards for security, transactions, and reliable messaging.
- 3. Â Stateful Operations : Ideal for operations that require maintaining a state between client and server.
- 4. Â Built-in Error Handling : Standardized fault reporting mechanism.
Disadvantages
- 1. Â Complexity : More complex to implement and maintain.
- 2. Â Performance : Generally slower due to the overhead of XML processing and extensive standards.
Use Cases :
- Enterprise-level applications requiring strict contracts and advanced security.
- Scenarios needing reliable and asynchronous messaging.
REST (Representational State Transfer)
Advantages :
- 1. Â Simplicity : Easier to implement and understand; uses standard HTTP methods.
- 2. Â Performance : Typically faster and more efficient due to lower overhead.
- 3. Â Scalability : Stateless nature allows for better scalability.
- 4. Â Flexibility : Supports multiple formats like JSON, XML, HTML, etc.
Disadvantages
- 1. Â Lack of Formal Contracts : No built-in contract definition mechanism.
- 2. Â Security : Less comprehensive security standards compared to SOAP.
Use Cases :
- Web applications requiring scalability and performance.
- Mobile applications and web services requiring lightweight communication.
Explanation in Java Example
Let’s consider two Java examples, one using SOAP and another using REST, for a simple calculator service that performs basic arithmetic operations.
1. Maven Dependencies (pom.xml)
xml
<dependencies>
<dependency>
<groupId>javax.xml.ws</groupId>
<artifactId>jaxws-api</artifactId>
<version>2.3.1</version>
</dependency>
<dependency>
<groupId>com.sun.xml.ws</groupId>
<artifactId>jaxws-rt</artifactId>
<version>2.3.1</version>
</dependency>
</dependencies>
2. SOAP Service Endpoint (CalculatorService.java)
java
import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.xml.ws.Endpoint;
@WebService
public class CalculatorService {
@WebMethod
public int add(int a, int b) {
return a + b;
}
@WebMethod
public int subtract(int a, int b) {
return a - b;
}
public static void main(String[] args) {
Endpoint.publish("http://localhost:8080/ws/calculator", new CalculatorService());
}
}
- 3. Â WSDL Generation :
- Deploy the service and access the WSDL at http://localhost:8080/ws/calculator?wsdl.
RESTful Web Service Example
1. Maven Dependencies (pom.xml)
xml
<dependencies>
<dependency>
<groupId>javax.ws.rs</groupId>
<artifactId>javax.ws.rs-api</artifactId>
<version>2.1.1</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.core</groupId>
<artifactId>jersey-server</artifactId>
<version>2.29.1</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-servlet</artifactId>
<version>2.29.1</version>
</dependency>
</dependencies>
2. RESTful Service Endpoint (CalculatorResource.java)
java
import javax.ws.rs.*;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
@Path("/calculator")
public class CalculatorResource {
@GET
@Path("/add")
@Produces(MediaType.APPLICATION_JSON)
public Response add(@QueryParam("a") int a, @QueryParam("b") int b) {
int result = a + b;
return Response.ok(result).build();
}
@GET
@Path("/subtract")
@Produces(MediaType.APPLICATION_JSON)
public Response subtract(@QueryParam("a") int a, @QueryParam("b") int b) {
int result = a - b;
return Response.ok(result).build();
}
}
3. Application Config Class (RestApplication.java)
java
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
@ApplicationPath("/api")
public class RestApplication extends Application {
// No need to implement any methods
}
4. web.xml Configuration
xml
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
version="3.1">
<display-name>CalculatorApp</display-name>
<servlet>
<servlet-name>Jersey Web Application</servlet-name>
<servlet-class>org.glassfish.jersey.servlet.ServletContainer</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.example.RestApplication</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>Jersey Web Application</servlet-name>
<url-pattern>/api/*</url-pattern>
</servlet-mapping>
</web-app>
Explanation
- SOAP Web Service :
- The CalculatorService class provides SOAP-based methods for addition and subtraction.
- The service is published at a specific URL, and the WSDL is generated automatically for clients to consume.
- RESTful Web Service :
- The CalculatorResource class provides RESTful endpoints for addition and subtraction using HTTP GET requests.
- The service uses query parameters and returns the results in JSON format.