java - API向Retrofit返回404

Question

我有一个API它会返回一个简单的 JSON 响应(响应代码 200)。但是当我从我的 Android 应用程序请求相同的 URL 时，它会得到 404。

这是依赖项

compile 'com.squareup.retrofit:retrofit:2.0.0-beta2'
compile 'com.squareup.okhttp:okhttp:2.6.0'
compile 'com.squareup.retrofit:converter-gson:2.0.0-beta2'
compile 'com.google.code.gson:gson:2.4'

这是我的界面

public interface ExampleApi {
    @GET("/test/drink/")
    Call<Example> getExample();
}

这些代码在MainActivity中运行

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://localpro.herokuapp.com/api")
    .addConverterFactory(GsonConverterFactory.create())
    .build();

ExampleApi api = retrofit.create(ExampleApi.class);
Call<Example> call = api.getExample();
call.enqueue(new Callback<Example>() {
    @Override
    public void onResponse(Response<Example> response, Retrofit retrofit) {
        try {
            Log.i("Response code", " " + response.code());
            Log.i("Response", " " + response.body().toString());
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    @Override
    public void onFailure(Throwable t) {
    }
});

日志

12-11 16:59:44.235 8885-8885/com.wealthpack.retrofitfinal I/Response code:  404 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at com.wealthpack.retrofitfinal.MainActivity$1.onResponse(MainActivity.java:45) 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at retrofit.ExecutorCallAdapterFactory$ExecutorCallback$1.run(ExecutorCallAdapterFactory.java:86)
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at android.os.Handler.handleCallback(Handler.java:746) 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:95) 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at android.os.Looper.loop(Looper.java:148) 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:5443) 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at java.lang.reflect.Method.invoke(Native Method) 
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:728)
12-11 16:59:44.236 8885-8885/com.wealthpack.retrofitfinal W/System.err:     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)

注意:几年后，我对 Android 开发和使用 Java 完全陌生。

Answer 1

这是一个语法问题，

你必须像这样编写你的服务:

Retrofit retrofit = new Retrofit.Builder()
    .baseUrl("https://localpro.herokuapp.com/api/")
    .addConverterFactory(GsonConverterFactory.create())
    .build();

public interface ExampleApi {
@GET("test/drink/")
Call<Example> getExample();

有关更多详细信息，请查看 Jake Wharton 的精彩演示 https://youtu.be/KIAoQbAu3eA?t=32m24s :)