java如何从Android调用RESTful web服务？

Question

我使用Jersey框架和Java在Netbean IDE中编写了一个REST web服务

对于用户需要提供用户名和密码的每个请求，我知道这种身份验证不是最佳做法（使用类似于：curl -u username:password -X PUT http://localhsot:8080/user的curl命令）

现在我想从Android类调用REST web服务

我该怎么做

我有一个Android类，它使用DefaultHttpClient和CredentialUsernameAndPassword，但当我在Eclipse中运行它时，有时会出现运行时异常或SDK异常

Answer 1

最近发现第三方库-Square Retrofit可以很好地完成这项工作

---

定义REST端点

public interface GitHubService {
   @GET("/users/{user}/repos")
   List<Repo> listRepos(@Path("user") String user,Callback<List<User>> cb);
}

---

获得具体服务

RestAdapter restAdapter = new RestAdapter.Builder()
    .setEndpoint("https://api.github.com")
    .build();
GitHubService service = restAdapter.create(GitHubService.class);

---

调用REST端点

List<Repo> repos = service.listRepos("octocat",new Callback<List<User>>() { 
    @Override
    public void failure(final RetrofitError error) {
        android.util.Log.i("example", "Error, body: " + error.getBody().toString());
    }
    @Override
    public void success(List<User> users, Response response) {
        // Do something with the List of Users object returned
        // you may populate your adapter here
    }
});

---

该库为您处理json序列化和反序列化。您也可以自定义序列化和反序列化

Gson gson = new GsonBuilder()
    .setFieldNamingPolicy(FieldNamingPolicy.LOWER_CASE_WITH_UNDERSCORES)
    .registerTypeAdapter(Date.class, new DateTypeAdapter())
    .create();

RestAdapter restAdapter = new RestAdapter.Builder()
    .setEndpoint("https://api.github.com")
    .setConverter(new GsonConverter(gson))
    .build();

Answer 2

使用Spring for Android和RestTemplate https://spring.io/guides/gs/consuming-rest-android/

// The connection URL 
String url = "https://ajax.googleapis.com/ajax/" + 
    "services/search/web?v=1.0&q={query}";

// Create a new RestTemplate instance
RestTemplate restTemplate = new RestTemplate();

// Add the String message converter
restTemplate.getMessageConverters().add(new StringHttpMessageConverter());

// Make the HTTP GET request, marshaling the response to a String
String result = restTemplate.getForObject(url, String.class, "Android");

Answer 3

我使用OkHttpClient调用restful web服务。这很简单

OkHttpClient httpClient = new OkHttpClient();
Request request = new Request.Builder()
                .url(url)
                .build();

Response response = httpClient.newCall(request).execute();
String body = response.body().string()