Recently, Rest architecture style or Restful web service is a hot topic for SOA, web service design and architecture style. But unfortunately, there are not many articles introducing how to develop a real restful web services. So, this series of articles try to introduce how to develop a Restful web services with CXF. The reason why i choose CXF is just because we are using CXF to develop SOAP web service, and CXF 2.1.X already supports JSR-311 API version 0.8 and CXF 2.2 plans to support JSR-311 1.0 API.
Some of the examples and comments are directly copies from CXF Restful page (http://cwiki.apache.org/CXF20DOC/restful-services.html), thanks for CXF team's great work.
This article will focus on a simplest service and how to config it as a Restful web service in tomcat. My tomcat version is 6.0.X.
Software: Tomcat 6.0.x, CXF 2.1
1. use CXF in Tomcat. please refer to CXF doc. It is pretty easy.
2. the major configuration file for CXF is WEB-INF/cxf-servlet.xml, we will add related configuration into this file.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:jaxrs="http://cxf.apache.org/jaxrs" <!-- This is the name space for jax rs -->
xmlns:jaxws="http://cxf.apache.org/jaxws"
xmlns:soap="http://cxf.apache.org/bindings/soap"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://cxf.apache.org/bindings/soap http://cxf.apache.org/schemas/configuration/soap.xsd
http://cxf.apache.org/jaxrs <!-- This is the schema location for CXF jax rs -->
http://cxf.apache.org/schemas/jaxrs.xsd <!-- This is the schema location for CXF jax rs xsd -->
http://cxf.apache.org/jaxws
http://cxf.apache.org/schemas/jaxws.xsd">
<!-- JAX-RS -->
<jaxrs:server id="customerService" address="/"> <!--NOTE: the address is relative address, the whole URL pattern will be http://localhost:8080/web app/services/, and the services -->
<jaxrs:serviceBeans>
<bean class="com.starcite.commonsearch.example.rs.CustomerServiceImpl" /> <!-- this is the class path, cannot be interface-->
</jaxrs:serviceBeans>
</jaxrs:server>
</beans>
3. Sample Service interface & implementation class
@Path("/customerservice/") <!-- URI for this service, the whole URI will be http://localhost:8080/web app/services/customerservice/ -->
public interface CustomerService {
@GET <!-- i guess @GET and @Path annotation is pretty easy to understand, if not, please read http://www.tkk7.com/justinchen/archive/2008/11/05/238760.html -->
@Path("/customers/") <!-- URI for this service, the whole URI will be http://localhost:8080/web app/services/customerservice/customers/ -->
public Customer getCustomers();
@GET
@Path("/customers/{id}/") <!-- URI for this service, the whole URI will be http://localhost:8080/web app/services/customerservice/customers/123/ etc -->
public Customer getCustomer(@PathParam("id") String id); <!-- @PathParam is the parameter extracts the value of a URI template parameter. -->
@PUT
@Path("/customers/")
public Response updateCustomer(Customer customer);
@POST
@Path("/customers/")
public Response addCustomer(Customer customer);
@DELETE
@Path("/customers/{id}/")
public Response deleteCustomer(@PathParam("id") String id);
@Path("/orders/{orderId}/")
public Order getOrder(@PathParam("orderId") String orderId);
}
Service impl class code. NOTE: there are no need any annotation. But also, there are a little bit different on return value comparing to SOAP web service. In SOAP web service, we can directly use any java class. But here, we used some special class, like Response, we will disucss this more in other articles.
public class CustomerServiceImpl implements CustomerService {
private long currentId = 123;
Map<Long, Customer> customers = new HashMap<Long, Customer>();
Map<Long, Order> orders = new HashMap<Long, Order>();
public CustomerServiceImpl() {
init();
}
public Customer getCustomers() {
System.out.println("----invoking getCustomer, Customer id is: XXX " );
Customer c = customers.get(123);
return c;
}
public Customer getCustomer(String id) {
System.out.println("----invoking getCustomer, Customer id is: " + id);
long idNumber = Long.parseLong(id);
Customer c = customers.get(idNumber);
return c;
}
public Response updateCustomer(Customer customer) {
System.out.println("----invoking updateCustomer, Customer name is: " + customer.getName());
Customer c = customers.get(customer.getId());
Response r;
if (c != null) {
customers.put(customer.getId(), customer);
r = Response.ok().build();
} else {
r = Response.notModified().build();
}
return r;
}
public Response addCustomer(Customer customer) {
System.out.println("----invoking addCustomer, Customer name is: " + customer.getName());
customer.setId(++currentId);
customers.put(customer.getId(), customer);
return Response.ok(customer).build();
}
public Response deleteCustomer(String id) {
System.out.println("----invoking deleteCustomer, Customer id is: " + id);
long idNumber = Long.parseLong(id);
Customer c = customers.get(idNumber);
Response r;
if (c != null) {
r = Response.ok().build();
customers.remove(idNumber);
} else {
r = Response.notModified().build();
}
return r;
}
public Order getOrder(String orderId) {
System.out.println("----invoking getOrder, Order id is: " + orderId);
long idNumber = Long.parseLong(orderId);
Order c = orders.get(idNumber);
return c;
}
final void init() {
Customer c = new Customer();
c.setName("John");
c.setId(123);
customers.put(c.getId(), c);
Order o = new Order();
o.setDescription("order 223");
o.setId(223);
orders.put(o.getId(), o);
}
}
4. POJO Class, such as Customer. POJO class is pretty similar, we can also use JAXB to covert object to XML.
@XmlRootElement(name = "Customer")
public class Customer {
private long id;
private String name;
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
5. Now, you can deploy this web app as normal web app. and after you start tomcat, you are able to try the following link in browser -
http://localhost:8080/vendor_search/services/customerservice/customers/ Or
http://localhost:8080/vendor_search/services/customerservice/customers/123/
the browser will return a XML for a cusomer object.
In next articles, we will implement more complex user case to prove the Restful web service.
posted on 2008-11-05 18:24
Justin Chen 閱讀(3513)
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