无法从我的Android模拟器连接到本地Web服务

Question

I am having a problem connecting from the emulator to a local web server. I can connect to it outside the emulator. Emulator gets: org.apache.http.conn.httphostconnectexception connection to http //localhost;808 refused

protected String doInBackground(String... args) {
        try {
            // Building Parameters
            List<NameValuePair> params = new ArrayList<NameValuePair>();
            // getting JSON string from URL
            JSONObject json = jParser.makeHttpRequest(url_all_products,
                    "GET", params);
            // Check your log cat for JSON reponse
            Log.d("All Products: ", json.toString());
            try {
                // Checking for SUCCESS TAG
                int success = json.getInt(TAG_SUCCESS);

                if (success == 1) {
                    // products found
                    // Getting Array of Products
                    products = json.getJSONArray(TAG_PRODUCTS);

                    // looping through All Products
                    for (int i = 0; i < products.length(); i++) {
                        JSONObject c = products.getJSONObject(i);

                        // Storing each json item in variable
                        String id = c.getString(TAG_PID);
                        String name = c.getString(TAG_NAME);

                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();

                        // adding each child node to HashMap key => value
                        map.put(TAG_PID, id);
                        map.put(TAG_NAME, name);

                        // adding HashList to ArrayList
                        productsList.add(map);
                    }
                } else {
                    // no products found
                    // Launch Add New product Activity
                    Intent i = new Intent(getApplicationContext(),
                            NewProductActivity.class);
                    // Closing all previous activities
                    i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(i);
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        } catch (Exception e) {
             System.out.println("Got an IOException: " + e.getMessage());
            // TODO: handle exception
        }
        return null;
    }

Answer 1

Try connecting to http://10.0.2.2:8080 instead.

The 10.0.2.2 IP address is special within the emulator and will transparently connect to your host development machine's localhost ( 127.0.0.1 ).

If you use localhost or 127.0.0.1 within the emulator, this will refer to the internal emulated loopback interface instead. This is useful if you have another program running in the emulator, acting as a TCP or UDP server at the same port. However, in your specific case, you really want to get 'out of the sandbox'.

The official documentation has more information (and examples).

Answer 2

You are probably using the wrong network address to access the web service.

http://localhost goes to the device in an Android emulator. Use 10.0.2.2 to access your host loopback interface (ie, 127.0.0.1 on your development machine).

See Android Emulator Networking

EDIT: Your exception says http //localhost;808 , but your hostname should be http //localhost:808 with a : instead of ; .