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RESTfu­­l Jav­a­ wit­h ­JAX­-­­RS 2.­0­ (Second Edition)

CacheControl and Other things

This project is a simple example showing usage CacheControl and Request.evaluatePreconditions().

System Requirements:

  • Maven 3.0.4 or higher

Building the project:

  1. In root directory mvn clean install

This will build a WAR and run it with embedded Jetty.

Source Code

Hierarchy

ex11_1
|-- pom.xml
`-- src
    |-- main
    |   |-- java
    |   |   `-- com
    |   |       `-- restfully
    |   |           `-- shop
    |   |               |-- domain
    |   |               |   `-- Customer.java
    |   |               `-- services
    |   |                   |-- CustomerResource.java
    |   |                   `-- ShoppingApplication.java
    |   `-- webapp
    |       `-- WEB-INF
    |           `-- web.xml
    `-- test
        `-- java
            `-- com
                `-- restfully
                    `-- shop
                        `-- test
                            `-- CustomerResourceTest.java

Details

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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/maven-v4_0_0.xsd">
    <parent>
        <groupId>com.oreilly.rest.workbook</groupId>
        <artifactId>jaxrs-2.0-workbook-pom</artifactId>
        <version>1.0</version>
        <relativePath>../pom.xml</relativePath>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.oreilly.rest.workbook</groupId>
    <artifactId>jaxrs-2.0-workbook-ex11_1</artifactId>
    <version>2.0</version>
    <packaging>war</packaging>
    <name>ex11_1</name>
    <description/>

    <dependencies>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jaxrs</artifactId>
            <version>3.0.12.Final-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-client</artifactId>
            <version>3.0.12.Final-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>async-http-servlet-3.0</artifactId>
            <version>3.0.12.Final-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>jaxrs-api</artifactId>
            <version>3.0.12.Final-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-servlet-initializer</artifactId>
            <version>3.0.12.Final-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.jboss.resteasy</groupId>
            <artifactId>resteasy-jaxb-provider</artifactId>
            <version>3.0.12.Final-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.1</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <finalName>ex11_1</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-deploy-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.eclipse.jetty</groupId>
                <artifactId>jetty-maven-plugin</artifactId>
                <version>9.0.6.v20130930</version>
                <configuration>
                    <webApp>
                        <contextPath>/</contextPath>
                    </webApp>
                    <scanIntervalSeconds>10</scanIntervalSeconds>
                    <stopKey>foo</stopKey>
                    <stopPort>9999</stopPort>
                    <stopWait>1</stopWait>
                </configuration>
                <executions>
                    <execution>
                        <id>start-jetty</id>
                        <phase>pre-integration-test</phase>
                        <goals>
                            <goal>run</goal>
                        </goals>
                        <configuration>
                            <scanIntervalSeconds>0</scanIntervalSeconds>
                            <daemon>true</daemon>
                        </configuration>
                    </execution>
                    <execution>
                        <id>stop-jetty</id>
                        <phase>post-integration-test</phase>
                        <goals>
                            <goal>stop</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <configuration>
                    <skip>true</skip>
                </configuration>
                <executions>
                    <execution>
                        <id>surefire-it</id>
                        <phase>integration-test</phase>
                        <goals>
                            <goal>test</goal>
                        </goals>
                        <configuration>
                            <skip>false</skip>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

src/main/webapp/WEB-INF/web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
      version="3.0">
</web-app>

src/main/java/com/restfully/shop/domain/Customer.java

package com.restfully.shop.domain;

import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import java.util.Date;

@XmlRootElement(name = "customer")
public class Customer
{
   private int id;
   private String firstName;
   private String lastName;
   private String street;
   private String city;
   private String state;
   private String zip;
   private String country;
   private String lastViewed = new Date().toString();

   @XmlAttribute
   public int getId()
   {
      return id;
   }

   public void setId(int id)
   {
      this.id = id;
   }

   @XmlElement(name = "first-name")
   public String getFirstName()
   {
      return firstName;
   }

   public void setFirstName(String firstName)
   {
      this.firstName = firstName;
   }

   @XmlElement(name = "last-name")
   public String getLastName()
   {
      return lastName;
   }

   public void setLastName(String lastName)
   {
      this.lastName = lastName;
   }

   @XmlElement
   public String getStreet()
   {
      return street;
   }

   public void setStreet(String street)
   {
      this.street = street;
   }

   @XmlElement
   public String getCity()
   {
      return city;
   }

   public void setCity(String city)
   {
      this.city = city;
   }

   @XmlElement
   public String getState()
   {
      return state;
   }

   public void setState(String state)
   {
      this.state = state;
   }

   @XmlElement
   public String getZip()
   {
      return zip;
   }

   public void setZip(String zip)
   {
      this.zip = zip;
   }

   @XmlElement
   public String getCountry()
   {
      return country;
   }

   public void setCountry(String country)
   {
      this.country = country;
   }

   public String getLastViewed()
   {
      return lastViewed;
   }

   public void setLastViewed(String lastViewed)
   {
      this.lastViewed = lastViewed;
   }

   @Override
   public String toString()
   {
      return "Customer{" +
              "id=" + id +
              ", firstName='" + firstName + '\'' +
              ", lastName='" + lastName + '\'' +
              ", street='" + street + '\'' +
              ", city='" + city + '\'' +
              ", state='" + state + '\'' +
              ", zip='" + zip + '\'' +
              ", country='" + country + '\'' +
              ", lastViewed='" + lastViewed + '\'' +
              '}';
   }

   @Override
   public int hashCode()
   {
      int result = id;
      result = 31 * result + (firstName != null ? firstName.hashCode() : 0);
      result = 31 * result + (lastName != null ? lastName.hashCode() : 0);
      result = 31 * result + (street != null ? street.hashCode() : 0);
      result = 31 * result + (city != null ? city.hashCode() : 0);
      result = 31 * result + (state != null ? state.hashCode() : 0);
      result = 31 * result + (zip != null ? zip.hashCode() : 0);
      result = 31 * result + (country != null ? country.hashCode() : 0);
      return result;
   }
}

src/main/java/com/restfully/shop/services/CustomerResource.java

package com.restfully.shop.services;

import com.restfully.shop.domain.Customer;

import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.CacheControl;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.EntityTag;
import javax.ws.rs.core.Request;
import javax.ws.rs.core.Response;
import java.net.URI;
import java.util.Date;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

@Path("/customers")
public class CustomerResource
{
   private Map<Integer, Customer> customerDB = new ConcurrentHashMap<Integer, Customer>();
   private AtomicInteger idCounter = new AtomicInteger();

   public CustomerResource()
   {
      Customer customer;
      int id = 1;

      customer = new Customer();
      customer.setId(id);
      customer.setFirstName("Bill");
      customer.setLastName("Burke");
      customer.setStreet("263 Clarendon Street");
      customer.setCity("Boston");
      customer.setState("MA");
      customer.setZip("02115");
      customer.setCountry("USA");
      customerDB.put(id++, customer);
   }

   @POST
   @Consumes("application/xml")
   public Response createCustomer(Customer customer)
   {
      customer.setId(idCounter.incrementAndGet());
      customerDB.put(customer.getId(), customer);
      System.out.println("Created customer " + customer.getId());
      return Response.created(URI.create("/customers/" + customer.getId())).build();

   }

   @GET
   @Path("{id}")
   @Produces("application/xml")
   public Response getCustomer(@PathParam("id") int id,
                               @HeaderParam("If-None-Match") String sent,
                               @Context Request request)
   {
      Customer cust = customerDB.get(id);
      if (cust == null)
      {
         throw new WebApplicationException(Response.Status.NOT_FOUND);
      }

      if (sent == null) System.out.println("No If-None-Match sent by client");

      EntityTag tag = new EntityTag(Integer.toString(cust.hashCode()));

      CacheControl cc = new CacheControl();
      cc.setMaxAge(5);


      Response.ResponseBuilder builder = request.evaluatePreconditions(tag);
      if (builder != null)
      {
         System.out.println("** revalidation on the server was successful");
         builder.cacheControl(cc);
         return builder.build();
      }


      // Preconditions not met!

      cust.setLastViewed(new Date().toString());
      builder = Response.ok(cust, "application/xml");
      builder.cacheControl(cc);
      builder.tag(tag);
      return builder.build();
   }


   @Path("{id}")
   @PUT
   @Consumes("application/xml")
   public Response updateCustomer(@PathParam("id") int id,
                                  @Context Request request,
                                  Customer update)
   {
      Customer cust = customerDB.get(id);
      if (cust == null) throw new WebApplicationException(Response.Status.NOT_FOUND);
      EntityTag tag = new EntityTag(Integer.toString(cust.hashCode()));

      Response.ResponseBuilder builder =
              request.evaluatePreconditions(tag);

      if (builder != null)
      {
         // Preconditions not met!
         return builder.build();
      }

      // Preconditions met, perform update

      cust.setFirstName(update.getFirstName());
      cust.setLastName(update.getLastName());
      cust.setStreet(update.getStreet());
      cust.setState(update.getState());
      cust.setZip(update.getZip());
      cust.setCountry(update.getCountry());


      builder = Response.noContent();
      return builder.build();
   }
}

src/main/java/com/restfully/shop/services/ShoppingApplication.java

package com.restfully.shop.services;

import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
import java.util.HashSet;
import java.util.Set;

@ApplicationPath("/services")
public class ShoppingApplication extends Application
{
   private Set<Object> singletons = new HashSet<Object>();

   public ShoppingApplication()
   {
      singletons.add(new CustomerResource());
   }

   @Override
   public Set<Object> getSingletons()
   {
      return singletons;
   }
}

src/test/java/com/restfully/shop/test/CustomerResourceTest.java

package com.restfully.shop.test;

import com.restfully.shop.domain.Customer;
import org.junit.AfterClass;
import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.Entity;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.EntityTag;
import javax.ws.rs.core.Response;


/**
 * @author <a href="mailto:bill@burkecentral.com">Bill Burke</a>
 * @version $Revision: 1 $
 */
public class CustomerResourceTest
{
   private static Client client;

   @BeforeClass
   public static void initClient()
   {
      client = ClientBuilder.newClient();
   }

   @AfterClass
   public static void closeClient()
   {
      client.close();
   }

   @Test
   public void testCustomerResource() throws Exception
   {
      WebTarget customerTarget = client.target("http://localhost:8080/services/customers/1");
      Response response = customerTarget.request().get();
      Assert.assertEquals(200, response.getStatus());
      Customer cust = response.readEntity(Customer.class);

      EntityTag etag = response.getEntityTag();
      response.close();

      System.out.println("Doing a conditional GET with ETag: " + etag.toString());
      response = customerTarget.request()
                               .header("If-None-Match", etag).get();
      Assert.assertEquals(304, response.getStatus());
      response.close();

      // Update and send a bad etag with conditional PUT
      cust.setCity("Bedford");
      response = customerTarget.request()
              .header("If-Match", "JUNK")
              .put(Entity.xml(cust));
      Assert.assertEquals(412, response.getStatus());
      response.close();
   }
}