Spring Rest Template Client：拒绝连接到http：// localhost：8080

Question

This my Android Activity

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

         pdialog=new ProgressDialog(this);

         query = getIntent().getExtras().getString("query");
         if(!TextUtils.isEmpty(query))
               new GetRestTask().execute(query);

}

private class GetRestTask extends AsyncTask<String, Void, ObjectExchanged>
{

    @Override
    protected void onPreExecute() {
        pdialog.setCancelable(true);
        pdialog.setMessage("Sending ....");
        pdialog.show();
    }

    @Override
    protected ObjectExchanged doInBackground(String... request) {
        Map<String, String> vars = new HashMap<String, String>();
      //   vars.put("query", ClientRestActivity.this.query);

        if(request != null && request.length > 0)
        {
            try
            {
                return ( getRestTemplate()).getForObject(URL, ObjectExchanged.class,query );

            }

            catch (RestClientException e) {

                e.printStackTrace();
                return null;

            }
        }
        return null;
    }

    @Override
    protected void onPostExecute(ObjectExchanged result) {

        if(result == null )
        {
            Toast.makeText(getApplicationContext(), "Non trouvé ou erreur", Toast.LENGTH_SHORT).show();

            pdialog.dismiss();          
        }
        else
        {
            Intent intent = new Intent(getApplicationContext(), ShowResults.class);

            intent.putExtra("list_uri", result.response);
            pdialog.dismiss();
        }

    }
}


private RestTemplate getRestTemplate() {
    if(restTemplate == null)
    {
        restTemplate = new RestTemplate();
        MappingJacksonHttpMessageConverter jsonConverter = new MappingJacksonHttpMessageConverter();
        List<MediaType> supportedMediaTypes = new ArrayList<MediaType>();
        supportedMediaTypes.add(MediaType.APPLICATION_JSON);
        jsonConverter.setSupportedMediaTypes(supportedMediaTypes);
        List<HttpMessageConverter<?>> listHttpMessageConverters = restTemplate.getMessageConverters();
        listHttpMessageConverters.add(jsonConverter);
        restTemplate.setMessageConverters(listHttpMessageConverters);
    }
    return restTemplate;
}

And this is my Servelet in server Side

protected void doGet(HttpServletRequest request, HttpServletResponse  response) throws ServletException, IOException {

    String query= request.getParameter("query");

    /*System.out.println(query);
    PrintWriter out2 = response.getWriter();
    out2.println("<LI> Parametre 1: " + query); 
    */

    System.out.println(query);
    PrintWriter out2 = response.getWriter();

    out2.println("done ");

    ArrayList<URI> uris= new ArrayList<>();

    try {
        Scanner s= new Scanner(new File ("urls.txt"));
        while (s.hasNext()) {
            uris.add(new URI(s.nextLine()));

        }
    } catch (Exception e) {
        // TODO: handle exception
    }
    ObjectExchanged objectExchanged = new ObjectExchanged(query,uris);


    if (objectExchanged.equals(null)) {
        System.out.println("null");
    }
    else 
        System.out.println("not null");

    Writer out =response.getWriter();
    String repJson = new Gson().toJson(objectExchanged);
    System.out.println(repJson);
    out.write(repJson);
}

I try to run this on my own device

This is the log

06-17 21:36:23.720: W/System.err(3010): org.springframework.web.client.ResourceAccessException: I/O error: Connection to http://localhost:8080 refused; nested exception is org.apache.http.conn.HttpHostConnectException: Connection to http://localhost:8080 refused
06-17 21:36:23.720: W/System.err(3010):     at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:456)
06-17 21:36:23.720: W/System.err(3010):     at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:404)
06-17 21:36:23.720: W/System.err(3010):     at org.springframework.web.client.RestTemplate.getForObject(RestTemplate.java:202)
06-17 21:36:23.720: W/System.err(3010):     at com.pfe.client.webservice.ClientRestActivity$GetRestTask.doInBackground(ClientRestActivity.java:74)
06-17 21:36:23.720: W/System.err(3010):     at com.pfe.client.webservice.ClientRestActivity$GetRestTask.doInBackground(ClientRestActivity.java:1)
06-17 21:36:23.720: W/System.err(3010):     at android.os.AsyncTask$2.call(AsyncTask.java:185)
06-17 21:36:23.720: W/System.err(3010):     at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:3        06)
06-17 21:36:23.720: W/System.err(3010):     at java.util.concurrent.FutureTask.run(FutureTask.java:138)
06-17 21:36:23.720: W/System.err(3010):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
06-17 21:36:23.730: W/System.err(3010):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
06-17 21:36:23.730: W/System.err(3010):     at java.lang.Thread.run(Thread.java:1019)
06-17 21:36:23.730: W/System.err(3010): Caused by: org.apache.http.conn.HttpHostConnectException: Connection to http://localhost:8080 refused
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:178)
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:359)
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
06-17 21:36:23.730: W/System.err(3010):     at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
06-17 21:36:23.730: W/System.err(3010):     at org.springframework.http.client.HttpComponentsClientHttpRequest.executeInternal(HttpComponentsClientHttpRequest.java:82)
06-17 21:36:23.730: W/System.err(3010):     at org.springframework.http.client.AbstractClientHttpRequest.execute(AbstractClientHttpRequest.java:52)
06-17 21:36:23.740: W/System.err(3010):     at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:441)
06-17 21:36:23.740: W/System.err(3010):     ... 10 more
06-17 21:36:23.740: W/System.err(3010): Caused by: java.net.ConnectException: /127.0.0.1:8080 - Connection refused
06-17 21:36:23.740: W/System.err(3010):     at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:207)
06-17 21:36:23.740: W/System.err(3010):     at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:437)
06-17 21:36:23.750: W/System.err(3010):     at java.net.Socket.connect(Socket.java:983)
06-17 21:36:23.750: W/System.err(3010):     at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
06-17 21:36:23.750: W/System.err(3010):     at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:143)
06-17 21:36:23.750: W/System.err(3010):     ... 19 more

Answer 1

localhost redirects calls by your router back to 127.0.0.1, which is the same device. So unless your server is on the phone, this will cause a crash. If you have a server that is connected to the same router network(wifi or lan) as your phone, then get the local IP of the server from your router or server and replace localhost with it.

Note: phone and server must be connected to the same router