Question

我正在测试凌空应用以获取JSON数据。我的测试成功地从在线站点获取它。但是当我将它连接到我的localhost节点js服务器时它没有获取它并且没有在控制台中触发异常，根本没有响应。即使我测试到通过浏览器发送get请求并且它工作并返回JSON数据，是的，我已经推出了我的机器的实际地址而不是＆＃34; localhost＆＃34;。那是我的Nodejs服务器代码：

var express=require('express');

var mongoose=require('mongoose');

//making the connections
mongoose.connect('mongodb://127.0.0.1:27017/db',function (error) {
if(error){console.log("error");}
else{

    console.log("connected!!");

 }

});




 //using the exported function to create the server
 var app=express();
// Port to be listened tos
var port=process.env.PORT || 3000;

app.get('/api',function(req,res){

res.json({firstname:'George',lastname:'Cloney'});
});

app.listen(port);

AppController.java：

public class AppController  extends Application{

public static final String TAG = AppController.class
        .getSimpleName();

private RequestQueue mRequestQueue;
private ImageLoader mImageLoader;

private static AppController mInstance;

@Override
public void onCreate() {

    super.onCreate();

    mInstance = this;
}

public static synchronized AppController getInstance() {
    return mInstance;
}

public RequestQueue getRequestQueue() {
    if (mRequestQueue == null) {
        mRequestQueue = Volley.newRequestQueue(getApplicationContext());
    }

    return mRequestQueue;
}

public ImageLoader getImageLoader() {
    getRequestQueue();
    if (mImageLoader == null) {
        mImageLoader = new ImageLoader(this.mRequestQueue,
                new LruBitmapCache());
    }
    return this.mImageLoader;
}

public <T> void addToRequestQueue(Request<T> req, String tag) {
    // set the default tag if tag is empty
    req.setTag(TextUtils.isEmpty(tag) ? TAG : tag);
    getRequestQueue().add(req);
}

public <T> void addToRequestQueue(Request<T> req) {
    req.setTag(TAG);
    getRequestQueue().add(req);
}

public void cancelPendingRequests(Object tag) {
    if (mRequestQueue != null) {
        mRequestQueue.cancelAll(tag);
    }
}
}

MainActivity.java：

 public class MainActivity extends AppCompatActivity {

TextView text;
private String url = "http://192.168.43.214:3000/api";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    text=(TextView)findViewById(R.id.text);

    JsonArrayRequest request = new JsonArrayRequest(url, new Response.Listener<JSONArray>() {
        @Override
        public void onResponse(JSONArray response) {
            //trying to test the response length but no results also
            text.setText(" "+response.length());
            for (int i = 0; i < response.length(); i++) {

                try {
                    JSONObject jsonObject = response.getJSONObject(i);

                    String fullname=jsonObject.getString("firstname");

                    text.setText(jsonObject.toString());

                                Toast.makeText(getApplicationContext(),fullname,Toast.LENGTH_LONG).show();

                } catch (JSONException e) {
                    e.printStackTrace();
                }


            }



            //Log.v("Data from the web: " , response.toString());


        }
    }, new Response.ErrorListener(){
        @Override
        public void onErrorResponse(VolleyError error) {

            VolleyLog.d("Mainactivity", error.getMessage());

        }
    });

    AppController.getInstance().addToRequestQueue(request);

}





   }

Answer 1

经过长时间的分析后，我发现该对象称为响应json数组，因此解决方案是通过响应json数组而不是json对象来返回节点js代码中的json数组：

res.json([{,}];

而不是

res.json({,});

将对象响应json数组及其功能放在方法中并在onCreate上调用它：

       void getJsonArray(url){
       //like before
       }

Android Volley应用程序与本地nodejs服务器

1 个答案: