我正在学习如何在 Android 中使用 Retrofit，但每当我尝试从互联网检索数据时，我的应用程序没有返回任何内容。我的响应没有成功返回，我不知道如何修复这个错误，目前我正在尝试使用 https://jsonplaceholder.typicode.com 这个 URL 发布和检索数据。我无法弄清楚是什么原因引起了这个问题。
> MainActivity
private void createpost() {
    Post post2 = new Post(1, "This is Title", "10");
    Call<Post> postCall = mWebService.createPost(post2);
    postCall.enqueue(new Callback<Post>() {
        @Override
        public void onResponse(Call<Post> call, Response<Post> response) {
            if (response.isSuccessful()) {
                Log.d(TAG, "response.isSuccessful()");
                mLog.setText(String.valueOf(response.code()));
                showPost(response.body());
            }
        }
        @Override
        public void onFailure(Call<Post> call, Throwable t) {
        }
    });
}
> Interface
public interface MyWebService {
    String BASE_URL = "https://jsonplaceholder.typicode.com/";
    Retrofit retrofit = new Retrofit.Builder()
            .baseUrl(BASE_URL)
            .addConverterFactory(GsonConverterFactory.create())
            .build();
    @POST("posts")
    Call<Post> createPost(@Body Post post);
}

出现未知原因的情况下，`https://jsonplaceholder.typicode.com` 抛出了套接字超时异常，与此同时，您可以检查另一个具有类似功能的网站 `https://reqres.in/`，以下是附在帖子中的示例代码：
```java
final HttpLoggingInterceptor httpLoggingInterceptor = new HttpLoggingInterceptor();
httpLoggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
final OkHttpClient okHttpClient = new OkHttpClient.Builder()
        .addInterceptor(httpLoggingInterceptor)
        .build();
final String host = "https://reqres.in/";
Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(HttpUrl.parse(host))
        .client(okHttpClient)
        .addConverterFactory(GsonConverterFactory.create())
        .build();
ReqResApi api = retrofit.create(ReqResApi.class);
api.createUser(new User("silentsudo", "dev"))
        .enqueue(new Callback<User>() {
            @Override
            public void onResponse(Call<User> call, Response<User> response) {
                System.out.println("响应成功: " + response.body().toString());
            }
            @Override
            public void onFailure(Call<User> call, Throwable throwable) {
                System.err.println("调用 API 时出错");
                throwable.printStackTrace();
            }
        });

interface ReqResApi {
    @POST("api/user")
    Call<User> createUser(@Body User post);
}

class User {
    private String name;
    private String job;
    public User(String name, String job) {
        this.name = name;
        this.job = job;
    }
    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", job='" + job + '\'' +
                '}';
    }
}

<details>
<summary>英文:</summary>
For unknown reason `https://jsonplaceholder.typicode.com` is throwing socket timeout exception, in the mean time you can check another website with similar functionality `https://reqres.in/` here is the sample code attached to post 
```java
final HttpLoggingInterceptor httpLoggingInterceptor = new HttpLoggingInterceptor();
        httpLoggingInterceptor.setLevel(HttpLoggingInterceptor.Level.BODY);
        final OkHttpClient okHttpClient = new OkHttpClient.Builder()
                .addInterceptor(httpLoggingInterceptor)
                .build();
        final String host = &quot;https://reqres.in/&quot;;
        Retrofit retrofit = new Retrofit.Builder()
                .baseUrl(HttpUrl.parse(host))
                .client(okHttpClient)
                .addConverterFactory(GsonConverterFactory.create())
                .build();
        ReqResApi api = retrofit.create(ReqResApi.class);
        api.createUser(new User(&quot;silentsudo&quot;, &quot;dev&quot;))
                .enqueue(new Callback&lt;User&gt;() {
                    @Override
                    public void onResponse(Call&lt;User&gt; call, Response&lt;User&gt; response) {
                        System.out.println(&quot;Resp Success full: &quot; + response.body().toString());
                    }
                    @Override
                    public void onFailure(Call&lt;User&gt; call, Throwable throwable) {
                        System.err.println(&quot;Error calling api&quot;);
                        throwable.printStackTrace();
                    }
                });

 interface ReqResApi {
        @POST("api/user")
        Call<User> createUser(@Body User post);
    }

class User {
        private String name;
        private String job;
        public User(String name, String job) {
            this.name = name;
            this.job = job;
        }
        @Override
        public String toString() {
            return "User{" +
                    "name='" + name + '\'' +
                    ", job='" + job + '\'' +
                    '}';
        }
    }