TDSI – Web Services com GlassFish, JTA / JPA e JSON (cliente) – parte 7

Antes leia:

TDSI – Web Services com GlassFish, JTA / JPA e JSON – parte 6

Agora vamos consumir o Web Service em um programa desktop (pode ser adpatado para funcionar no Android) .

Crie num novo projeto, chamado consometdsiWS tipo Aplicação Java. Dentro dele faça um cópia do pacote Model juntamente com as classes Marca.java e Modelo.java.

Vamos retirar todas as anotações (annotations) JPA (retire os imports também) e deixar somente as Jackson como abaixo:

Marca.java

package model;

import com.fasterxml.jackson.annotation.JsonIdentityInfo;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;
import java.util.Date;
import java.util.List;

@JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id")
public class Marca {
 @JsonProperty("id")
 private Long CodMarca;
 private String NomeMarca;

 private Date dtfundacao;
 // getters e setters
}

Modelo.java

package model;

import com.fasterxml.jackson.annotation.JsonIdentityInfo;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.ObjectIdGenerators;

@JsonIdentityInfo(generator=ObjectIdGenerators.PropertyGenerator.class, property="id",scope = Marca.class)
public class Modelo {
 @JsonProperty("id")
 private Long CodModelo;
 private String DescricaoModelo;

 private Marca marca;

 geters e seters
}

E no programa principal vamos colocar os seguintes códigos:

consometdsiWS.java

package consometdsiws;

import com.fasterxml.jackson.databind.ObjectMapper;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import model.Marca;

public class ConsometdsiWS {

 private static final String targetURL =
 "http://localhost:8080/tdsiWS/webresources/tdsi/listarmarca"; 

 public static void main(String[] args) throws MalformedURLException, IOException {

 URL restServiceURL = new URL(targetURL);
 HttpURLConnection httpConnection = (HttpURLConnection) restServiceURL.openConnection();
 httpConnection.setRequestMethod("GET");
 httpConnection.setRequestProperty("Accept", "application/json");

 if (httpConnection.getResponseCode() != 200) {
 throw new RuntimeException("HTTP GET Request Failed with Error code : "
 + httpConnection.getResponseCode());
 }

 BufferedReader responseBuffer =
 new BufferedReader(new InputStreamReader((httpConnection.getInputStream())));

 String output;
 String json = new String();

 while ((output = responseBuffer.readLine()) != null) {
 json = json + output;
 }

 ObjectMapper mapper = new ObjectMapper();

 Marca marca;

 marca = mapper.readValue(json, Marca.class);

 httpConnection.disconnect();

 }

}

E o Web Service foi consumido.

Links dos códigos completos

Marca.java

Modelo.java

consometdsi.java