JAX-RS 2.0 RESTEasy 3.0.2.Final 客户端 API 示例 - 《HowToDoInJava 中文系列教程》

JAX-RS RESTEasy API
客户端代码
Maven 配置

原文： https://howtodoinjava.com/resteasy/jax-rs-2-0-resteasy-3-0-2-final-client-api-example/

JAX-RS 2.0 在以前的版本中带来了很多改进。主要改进之一是客户端 API，它在 JAX-RS 1.0 中完全丢失。尽管编写可移植的 JAX-RS 服务很容易，但是每个 JAX-RS 实现都定义了自己的专有 API。 JAX-RS 2.0 用流畅的，低级的请求构建 API 填补了这一空白。这是一个简单的示例：

    Client client = ClientFactory.newClient(); 
    WebTarget target = client.target("http://localhost:8080/howtodoinjava"); 
    Form form = new Form().param("customer", "Bill").param("product", "book"); 
    Response response = target.request().post(Entity.form(form)); 
    Order order = response.readEntity(Order.class);

上面的代码特定于 JAX-RS 2.0，并使用 JAX-RS 类。如果您正在使用最新的 RESTEasy （版本 3）内部版本，则可以使用其客户端 API 提供的 RESTEasy 抽象的这些较低级别的 JAX-RS 2.0 API。

JAX-RS RESTEasy API

让我们以示例网络服务 API 为例，我们将在客户端代码中对其进行访问：

    @GET
    @Path("/users")
    @Produces("application/vnd.com.demo.user-management.users+xml;charset=UTF-8;version=1")
    public Users getAllUsers() {
        User user1 = new User();
        user1.setId(1);
        user1.setFirstName("demo");
        user1.setLastName("user");
        user1.setUri("/user-management/users/1");
        User user2 = new User();
        user2.setId(2);
        user2.setFirstName("Mark");
        user2.setLastName("Dwain");
        user2.setUri("/user-management/users/2");
        Users users = new Users();
        users.setUsers(new ArrayList<User>());
        users.getUsers().add(user1);
        users.getUsers().add(user2);
        return users;
    }
    @POST
    @Path("/users")
    @Consumes("application/vnd.com.demo.user-management.user+xml;charset=UTF-8;version=1")
    public Response createUser(User user,
            @DefaultValue("false") @QueryParam("allow-admin") boolean allowAdmin)
            throws URISyntaxException {
        System.out.println(user.getFirstName());
        System.out.println(user.getLastName());
        return Response.status(201)
                .contentLocation(new URI("/user-management/users/123")).build();
    }

客户端代码

现在，使用新客户端代码访问这些 API：

package test.jaxrs2;
import javax.ws.rs.client.Entity;
import javax.ws.rs.core.Response;
import org.jboss.resteasy.client.jaxrs.ResteasyClient;
import org.jboss.resteasy.client.jaxrs.ResteasyClientBuilder;
import org.jboss.resteasy.client.jaxrs.ResteasyWebTarget;
import com.demo.rest.model.User;
import com.demo.rest.model.Users;
public class Demo_JAXRS_2_Example 
{
    public static void main(String[] args) 
    {
        getExample_one();
        getExample_two();
        postExample();
    }
    private static void getExample_one() 
    {
        ResteasyClient client = new ResteasyClientBuilder().build();
        ResteasyWebTarget target = client.target("http://localhost:8080/RESTEasyApplication/user-management/users");
        Response response = target.request().get();
        //Read output in string format
        String value = response.readEntity(String.class);
        System.out.println(value);
        response.close();  
    }
    private static void getExample_two()
    {
        ResteasyClient client = new ResteasyClientBuilder().build();
        ResteasyWebTarget target = client.target("http://localhost:8080/RESTEasyApplication/user-management/users");
        Response response = target.request().get();
        //Read the entity
        Users users = response.readEntity(Users.class);
        for(User user : users.getUsers()){
            System.out.println(user.getId());
            System.out.println(user.getLastName());
        }
        response.close();  
    }
    private static void postExample() 
    {
        User user = new User();
        user.setFirstName("john");
        user.setLastName("Maclane");
        ResteasyClient client = new ResteasyClientBuilder().build();
        ResteasyWebTarget target = client.target("http://localhost:8080/RESTEasyApplication/user-management/users");
        Response response = target.request().post(Entity.entity(user, "application/vnd.com.demo.user-management.user+xml;charset=UTF-8;version=1"));
        //Read output in string format
        System.out.println(response.getStatus());
        response.close();  
    }
}
Output in console:
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<users>
<user id="1" uri="/user-management/users/1"><firstName>demo</firstName><lastName>user</lastName></user>
<user id="2" uri="/user-management/users/2"><firstName>demo</firstName><lastName>user</lastName></user>
</users>
1
user
2
Dwain
201

Maven 配置

我已经使用下面的 Maven 配置来运行这些示例。

  <repositories>
    <repository>
      <id>jboss</id>
      <url>http://repository.jboss.org/maven2</url>
    </repository>
  </repositories>
  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>
     <!-- core library -->
     <dependency>
        <groupId>org.jboss.resteasy</groupId>
         <artifactId>resteasy-jaxrs</artifactId>
        <version>3.0.2.Final</version>
     </dependency>
    <!-- JAXB support -->
    <dependency>
      <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-jaxb-provider</artifactId>
      <version>3.0.2.Final</version>
    </dependency>
    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>jaxrs-api</artifactId>
        <version>3.0.2.Final</version>
    </dependency>
    <dependency>
        <groupId>org.jboss.resteasy</groupId>
        <artifactId>resteasy-client</artifactId>
        <version>3.0.2.Final</version>
    </dependency>
    <dependency>
        <groupId>net.sf.scannotation</groupId>
        <artifactId>scannotation</artifactId>
        <version>1.0.3</version>
    </dependency>
  </dependencies>

要下载以上示例的源代码，请点击以下链接。

[下载源码](https://docs.google.com/file/d/0B7yo2HclmjI4NS1IQUZLUjI1Q0U/edit?usp=sharing "jax-rs 2.0 resteasy client code swource code")

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