Http Post a JSON Object to API [Solved]

Fritjof

Hello! I am trying to get the Sentiment API running in processing. I have used the template found here, and after some tinkering I seem to have almost gotten it working (I hope!).

However I am still not able to print the text that I want. I can't find any errors, but the API is not responding. I've put println's throughout the code, and at line 63: InputStream in = conn.getInputStream(); it seems to malfunction, as I can read the println '7', but not '8' which is immediately after that line. Testing on mashape leads me to believe the API works otherwise, so I think it is due to some error of my own.

Here is the code:

import java.io.*;
import java.net.*;
import java.net.HttpURLConnection;
import java.net.URL;

StringBuilder response = new StringBuilder();
JSONObject ezm;
//HttpURLConnection conn;

void setup() {

  size(300,300);
  ezm = new JSONObject();
  ezm.setString("txt", "Happy days");

  URL url = null;
  println(1);
try
{
url = new URL("http://sentiment.vivekn.com/api/text/");
println(2);
}
catch (MalformedURLException ex)
{
println("Url fejler");
}
if(url == null)
{
println("url øv");
}

  try {
    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
    println(3);
    try {
      conn.setRequestMethod("POST"); //use post method
      conn.setDoOutput(true); //we will send stuff
      conn.setDoInput(true); //we want feedback
      conn.setUseCaches(false); //no caches
      conn.setAllowUserInteraction(false);
      conn.setRequestProperty("Accept","application/json");
      conn.setRequestProperty("Content-Type","application/json");
      println(4);
    } 
    catch (ProtocolException e) {
      println("æv");
    }
    OutputStream out = conn.getOutputStream();
    try {
      OutputStreamWriter wr = new OutputStreamWriter(out);
      wr.write(ezm.toString()); //ezm is my JSON object containing the api commands
      wr.flush();
      wr.close();
      println(5);
    }

    finally { //in this case, we are ensured to close the output stream
      if (out != null)
        out.close();
        println(6);
    }
    println(7);
    InputStream in = conn.getInputStream(); 
    println(8);
    BufferedReader rd = null;
    try {
      rd = new BufferedReader(new InputStreamReader(in));
      String responseSingle = null;
      while ((responseSingle = rd.readLine()) != null) {
        response.append(responseSingle);
      }
      println("The server response is " + response);
    }
    catch (IOException e) {
      println("hm");
    }
    finally {  //in this case, we are ensured to close the input stream
      if (in != null)
        in.close();
    }
  }
  catch (IOException e) {
  } 
  finally {  //in this case, we are ensured to close the connection itself 

 }
}

Hope someone can spot the errors! Thank you

F

Edit: The code tag seems to have put html around the link in my code. Please ignore that

Fritjof

Simon Brix is a wizard. Here is the functional code, with some obsolete parts:

import java.io.*;
import java.net.*;
import java.net.HttpURLConnection;
import java.net.URL;

StringBuilder response = new StringBuilder();
JSONObject ezm;
HttpURLConnection conn = null;

static class Util {
public static String streamToString(InputStream is) throws IOException {
        StringBuilder sb = new StringBuilder();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));
        String line;
        while ((line = rd.readLine()) != null) {
            sb.append(line);
        }
        return sb.toString();
    }
}

void setup() {

  size(300,300);
  ezm = new JSONObject();
  ezm.setString("txt", "I am sad");

  URL url = null;
try
{
url = new URL("http://sentiment.vivekn.com/api/text/");
}
catch (MalformedURLException ex)
{
println("Url fejler");
}
if(url == null)
{
print("url øv");
}

  try {
    conn = (HttpURLConnection) url.openConnection();
    try {
      conn.setRequestMethod("POST"); //use post method
      conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
      conn.setRequestProperty("Accept", "application/json");
      conn.setDoOutput(true); //we will send stuff
      //conn.setDoInput(true); //we want feedback
      //conn.setUseCaches(false); //no caches
      //conn.setAllowUserInteraction(false);
      OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
      wr.write("txt=Very bad"); //ezm is my JSON object containing the api commands
      wr.flush();
      wr.close();
      print("Test2");
      print("Test1");
      /*int responseCode = conn.getResponseCode();
    String responseMessage = conn.getResponseMessage();

    InputStream is = null;
    if (responseCode >= 400) {
      is = conn.getErrorStream();
    } else {
      is = conn.getInputStream();
    }


    String resp = responseCode + "\n" + responseMessage + "\n>" + Util.streamToString(is) + "<\n";

    print(resp);*/
    } 
    catch (ProtocolException e) {
      println("æv");
    }

    print("Test3");

// Open a stream which can read the server response*********************************
    print("Test4");

    InputStream in = conn.getInputStream();
    print("Test5");
    BufferedReader rd = null;
    print("Test6");
    try {
      print("Test7");
      rd = new BufferedReader(new InputStreamReader(in));
      String responseSingle = null;
      print("Test8");
      while ((responseSingle = rd.readLine()) != null) {
        response.append(responseSingle);
        print("Test9");
      }
      println("The server response is " + response);
    }
    catch (IOException e) {
      println("hm");
    }
    finally {  //in this case, we are ensured to close the input stream
      if (in != null)
        in.close();
    }
  }
  catch (IOException e) {
  } 
  finally {  //in this case, we are ensured to close the connection itself 

 }
}