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Error in formating the URL for chatGPT's API

I am trying to make a program where a user can asks GPT-3 a question through its API.
I tried to get GPT-3's assistant to design code for me, however there were some errors because it uses outdated information from 2021. Below is my modified code after going through the documentation, but I still cant get it to work, it is generating a 'java.io.FileNotFoundException' error.
I believe the problem is with the formatting of the completion section of my URL, however I am not sure. If anyone could tell me what's wrong it would be greatly appreciated.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
public class ChatGPT{
public static void main(String[] args) throws IOException {
String prompt = "What country has the most moderate weather?";
String model = "text-curie-001";
String apiKey = /*My API key*/;
// Encode the prompt and construct the API request URL
String url = String.format(
"https://api.openai.com/v1/completions?model=%s&prompt=%s",
model,
URLEncoder.encode(prompt, "UTF-8")
);
// Create the request
HttpURLConnection conn = (HttpURLConnection) new URL(url).openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Authorization", "Bearer " + apiKey);
// Make the request and retrieve the response
BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
StringBuilder responseBody = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
responseBody.append(line);
}
reader.close();
// Print the response
System.out.println(responseBody);
}
}
I know my API key is valid because changing the url to whats shown below outputs the appropriate information:
String url = String.format(
"https://api.openai.com/v1/models/%s",
model
);
the format "/v1/models/text-curie-001" outputs the details for the model 'text-curie-001'
the format "/v1/completions..." outputs a response based on the given prompt.

Copy of InputStream blocks with Jetty HTTP client using an InputStreamResponseListener

Im am using Jetty 9.4.8 HTTP client and want to write a stream of incoming data to a file. Currently I am using an InputStreamResponseListener and IOUtils.copy(..) writing to a FileOutputStream. I have also tried Files.copy().
InputStreamResponseListener streamResponseListener = new InputStreamResponseListener();
request.send(streamResponseListener);
if(streamResponseListener.get(5, TimeUnit.MINUTES).getStatus() == 200) {
OutputStream outputStream = null;
try {
TMP_FILE.toFile().createNewFile();
outputStream = new FileOutputStream(TMP_FILE.toFile());
IOUtils.copy(inputStream, outputStream);
} catch(IOException e) {
this.getLogService().log(..)
} finally {
IOUtils.closeQuietly(inputStream);
IOUtils.closeQuietly(outputStream);
}
// NOT REACHED IN CASE InputStream is BLOCKED FOR SOME REASON
}
However, the copy methods seem to block after all bytes have been received. Why could this happen and how can I avoid this?
Headers of the HTTP content requested:
Date: Wed, 23 May 2018 16:46:06 GMT
Content-Type: application/octet-stream
Content-Disposition: attachment; filename=".."
Content-Length: 613970044
Server: Jetty(9.4.8.v20171121)
IOUtils from Apache Commons IO Version 2.4

Here's a working example of your codebase, using only Java and Jetty.
This is requesting content from a server that is known to comply with the HTTP spec.
package demo.jettyclient;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URI;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.Properties;
import java.util.concurrent.TimeUnit;
import org.eclipse.jetty.client.HttpClient;
import org.eclipse.jetty.client.api.Request;
import org.eclipse.jetty.client.api.Response;
import org.eclipse.jetty.client.util.InputStreamResponseListener;
import org.eclipse.jetty.http.HttpStatus;
import org.eclipse.jetty.util.IO;
import org.eclipse.jetty.util.StringUtil;
import org.eclipse.jetty.util.ssl.SslContextFactory;
public class DownloadUrl
{
public static void main(String[] args) throws Exception
{
String uriString = "https://upload.wikimedia.org/wikipedia/en/a/a1/Jetty_logo.png?download";
if (args.length >= 1)
uriString = args[0];
URI srcUri = URI.create(uriString);
SslContextFactory ssl = new SslContextFactory(true);
HttpClient client = new HttpClient(ssl);
try
{
client.start();
Request request = client.newRequest(srcUri);
System.out.printf("Using HttpClient v%s%n", getHttpClientVersion());
System.out.printf("Requesting: %s%n", srcUri);
InputStreamResponseListener streamResponseListener = new InputStreamResponseListener();
request.send(streamResponseListener);
Response response = streamResponseListener.get(5, TimeUnit.SECONDS);
if (response.getStatus() != HttpStatus.OK_200)
{
throw new IOException(
String.format("Failed to GET URI [%d %s]: %s",
response.getStatus(),
response.getReason(),
srcUri));
}
Path tmpFile = Files.createTempFile("tmp", ".dl");
try (InputStream inputStream = streamResponseListener.getInputStream();
OutputStream outputStream = Files.newOutputStream(tmpFile))
{
IO.copy(inputStream, outputStream);
}
System.out.printf("Downloaded %s%n", srcUri);
System.out.printf("Destination: %s (%,d bytes)%n", tmpFile.toString(), Files.size(tmpFile));
}
finally
{
client.stop();
}
}
private static String getHttpClientVersion()
{
ClassLoader cl = HttpClient.class.getClassLoader();
// Attempt to use maven pom properties first
String pomResource = "/META-INF/maven/org/eclipse/jetty/jetty-client/pom.properties";
URL url = cl.getResource(pomResource);
if (url != null)
{
try (InputStream in = url.openStream())
{
Properties props = new Properties();
props.load(in);
String version = props.getProperty("version");
if (StringUtil.isNotBlank(version))
return version;
}
catch (IOException ignore)
{
}
}
// Attempt to use META-INF/MANIFEST.MF
String version = HttpClient.class.getPackage().getImplementationVersion();
if (StringUtil.isNotBlank(version))
return version;
return "<unknown>";
}
}
When run, this results in ...
2018-05-23 10:52:08.401:INFO::main: Logging initialized #325ms to org.eclipse.jetty.util.log.StdErrLog
Using HttpClient v9.4.9.v20180320
Requesting: https://upload.wikimedia.org/wikipedia/en/a/a1/Jetty_logo.png?download
Downloaded https://upload.wikimedia.org/wikipedia/en/a/a1/Jetty_logo.png?download
Destination: C:\Users\joakim\AppData\Local\Temp\tmp2166600286896937563.dl (11,604 bytes)
Process finished with exit code 0
One (or more) of the following is likely causing your issue.
There is either something wrong with your server, not complying with the HTTP spec.
The HTTP exchange isn't complete yet (from the protocol point of view). Capture the traffic and verify the behavior.
The IOUtil library you are using (you didn't say which one) has a bug.
The fact that wget (or curl) works is likely because they are not strict with Content-Length (per recommendations in RFC7230) and will display / download all content received until physical connection EOF/disconnect. While the HTTP/1.1 protocol has a connection persistence and strict rules on when the request (and response) content ends.

Cannot access azure blobs through rest api

I was able to create a Container in Storage Account and upload a blob to it through the Client Side Code.
I was able to make the blob available for Public access as well , such that when I hit the following query from my browser, I am able to see the image which I uploaded.
https://MYACCOUNT.blob.core.windows.net/MYCONTAINER/MYBLOB
I now have a requirement to use the rest service to retrieve the contents of the blob. I wrote down the following java code.
package main;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
public class GetBlob {
public static void main(String[] args) {
String url="https://MYACCOUNT.blob.core.windows.net/MYCONTAINER/MYBLOB";
try {
System.out.println("RUNNIGN");
HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
connection.setRequestProperty("Authorization", createQuery());
connection.setRequestProperty("x-ms-version", "2009-09-19");
InputStream response = connection.getInputStream();
System.out.println("SUCCESSS");
String line;
BufferedReader reader = new BufferedReader(new InputStreamReader(response));
while ((line = reader.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
e.printStackTrace();
}
}
public static String createQuery()
{
String dateFormat="EEE, dd MMM yyyy hh:mm:ss zzz";
SimpleDateFormat dateFormatGmt = new SimpleDateFormat(dateFormat);
dateFormatGmt.setTimeZone(TimeZone.getTimeZone("UTC"));
String date=dateFormatGmt.format(new Date());
String Signature="GET\n\n\n\n\n\n\n\n\n\n\n\n" +
"x-ms-date:" +date+
"\nx-ms-version:2009-09-19" ;
// I do not know CANOCALIZED RESOURCE
//WHAT ARE THEY??
// +"\n/myaccount/myaccount/mycontainer\ncomp:metadata\nrestype:container\ntimeout:20";
String SharedKey="SharedKey";
String AccountName="MYACCOUNT";
String encryptedSignature=(encrypt(Signature));
String auth=""+SharedKey+" "+AccountName+":"+encryptedSignature;
return auth;
}
public static String encrypt(String clearTextPassword) {
try {
MessageDigest md = MessageDigest.getInstance("SHA-256");
md.update(clearTextPassword.getBytes());
return new sun.misc.BASE64Encoder().encode(md.digest());
} catch (NoSuchAlgorithmException e) {
}
return "";
}
}
However , I get the following error when I run this main class...
RUNNIGN
java.io.IOException: Server returned HTTP response code: 403 for URL: https://klabs.blob.core.windows.net/delete/Blob_1
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(Unknown Source)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(Unknown Source)
at main.MainClass.main(MainClass.java:61)
Question1: Why this error, did I miss any header/parameter?
Question2: Do I need to add headers in the first place, because I am able to hit the request from the browser without any issues.
Question3: Can it be an SSL issue? What is the concept of certificates, and how and where to add them? Do I really need them? Will I need them later, when I do bigger operations on my blob storage(I want to manage a thousand blobs)?
Will be thankful for any reference as well, within Azure and otherwise that could help me understand better.
:D
AFTER A FEW DAYS
Below is my new code for PutBlob I azure. I believe I have fully resolved all header and parameter issues and my request is perfect. However I am still getting the same 403. I do not know what the issue is. Azure is proving to be pretty difficult.
A thing to note is that the containers name is delete, and I want to create a blob inside it, say newBlob. I tried to initialize the urlPath in the code below with both "delete" and "delete/newBlob".
Does not work..
package main;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import com.sun.org.apache.xml.internal.security.exceptions.Base64DecodingException;
import com.sun.org.apache.xml.internal.security.utils.Base64;
public class Internet {
static String key="password";
static String account="klabs";
private static Base64 base64 ;
private static String createAuthorizationHeader(String canonicalizedString) throws InvalidKeyException, Base64DecodingException, NoSuchAlgorithmException, IllegalStateException, UnsupportedEncodingException {
Mac mac = Mac.getInstance("HmacSHA256");
mac.init(new SecretKeySpec(base64.decode(key), "HmacSHA256"));
String authKey = new String(base64.encode(mac.doFinal(canonicalizedString.getBytes("UTF-8"))));
String authStr = "SharedKey " + account + ":" + authKey;
return authStr;
}
public static void main(String[] args) {
System.out.println("INTERNET");
String key="password";
String account="klabs";
long blobLength="Dipanshu Verma wrote this".getBytes().length;
File f = new File("C:\\Users\\Dipanshu\\Desktop\\abc.txt");
String requestMethod = "PUT";
String urlPath = "delete";
String storageServiceVersion = "2009-09-19";
SimpleDateFormat fmt = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:sss");
fmt.setTimeZone(TimeZone.getTimeZone("UTC"));
String date = fmt.format(Calendar.getInstance().getTime()) + " UTC";
String blobType = "BlockBlob";
String canonicalizedHeaders = "x-ms-blob-type:"+blobType+"\nx-ms-date:"+date+"\nx-ms-version:"+storageServiceVersion;
String canonicalizedResource = "/"+account+"/"+urlPath;
String stringToSign = requestMethod+"\n\n\n"+blobLength+"\n\n\n\n\n\n\n\n\n"+canonicalizedHeaders+"\n"+canonicalizedResource;
try {
String authorizationHeader = createAuthorizationHeader(stringToSign);
URL myUrl = new URL("https://klabs.blob.core.windows.net/" + urlPath);
HttpURLConnection connection=(HttpURLConnection)myUrl.openConnection();
connection.setRequestProperty("x-ms-blob-type", blobType);
connection.setRequestProperty("Content-Length", String.valueOf(blobLength));
connection.setRequestProperty("x-ms-date", date);
connection.setRequestProperty("x-ms-version", storageServiceVersion);
connection.setRequestProperty("Authorization", authorizationHeader);
connection.setDoOutput(true);
connection.setRequestMethod("POST");
System.out.println(String.valueOf(blobLength));
System.out.println(date);
System.out.println(storageServiceVersion);
System.out.println(stringToSign);
System.out.println(authorizationHeader);
System.out.println(connection.getDoOutput());
DataOutputStream outStream = new DataOutputStream(connection.getOutputStream());
// Send request
outStream.writeBytes("Dipanshu Verma wrote this");
outStream.flush();
outStream.close();
DataInputStream inStream = new DataInputStream(connection.getInputStream());
System.out.println("BULLA");
String buffer;
while((buffer = inStream.readLine()) != null) {
System.out.println(buffer);
}
// Close I/O streams
inStream.close();
outStream.close();
} catch (InvalidKeyException | Base64DecodingException | NoSuchAlgorithmException | IllegalStateException | UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
I know only a proper code reviewer might be able to help me, please do it if you can.
Thanks

Question1: Why this error, did I miss any header/parameter?
Most likely you're getting this error is because of incorrect signature. Please refer to MSDN documentation for creating correct signature: http://msdn.microsoft.com/en-us/library/azure/dd179428.aspx. Unless your signature is correct you'll not be able to perform operations using REST API.
Question2: Do I need to add headers in the first place, because I am
able to hit the request from the browser without any issues.
In your current scenario, because you can access the blob directly (which in turn means the container in which the blob exist has Public or Blob ACL) you don't really need to use REST API. You can simply make a HTTP request using Java and read the response stream which will have blob contents. You would need to go down this route if the container ACL is Private because in this case your requests need to be authenticated and the code above creates an authenticated request.
Question3: Can it be an SSL issue? What is the concept of
certificates, and how and where to add them? Do I really need them?
Will I need them later, when I do bigger operations on my blob
storage(I want to manage a thousand blobs)?
No, it is not an SSL issue. Its an issue with incorrect signature.

Finally found the mistake!!
In the code above , I was using a String "password" as key for my SHA2
base64.decode(key)
It should have been the key associated with my account with AZURE.
Silly One!! Took me 2 weeks to find.

HTTP Request passing Keywords to search

I made some research to solve my problem but sadly until now I couldn't. It's not such a big deal but I've stuck on it..
I need to make a search with some keywords in search engines such as google. I got two class here to do this:
package com.sh.st;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class EventSearch extends SearchScreen implements ActionListener {
public EventSearch(){
btsearch.addActionListener(this);
}
public void actionPerformed(ActionEvent e){
if(e.getSource()==btsearch){
String query=txtsearch.getText();
}
}
}
and
package com.sh.st;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
public class HttpRequest extends SearchScreen
{
URL url = new URL("google.com" + "?" + query).openConnection();
URLConnection connection = url.openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8"); //Possible Incompatibility
InputStream response = connection.getInputStream();
}
So, txtsearch comes from another class named SearchScreen and I attributed the value to one string named query. I need to pass query to HttpRequest class and to do this I just extend, I'm sure it's wrong but I saw someone else doing this; and this is the first problem, how may I do this?
the second and most important I'm receiving syntax error:
I didn't fully understand the meaning and utility of "connection.setRequestProperty("Accept-Charset", "UTF-8");"
'course reading I can understand that is regarding the caracters that probably will come up from my request but even though the syntax error is not clear for me
I made research in links such:
How to send HTTP request in java?
getting text from password field
http://www.xyzws.com/Javafaq/how-to-use-httpurlconnection-post-data-to-web-server/139
Using java.net.URLConnection to fire and handle HTTP requests
All of them have a good material but I can't fully understand everything on it and the part the I'm trying to follow is not working. Could anyone help me please?
Edit: [Topic Solved]

Try this code: (comments inlined)
// Fixed search URL; drop openConnection() at the end
URL url = new URL("http://google.com/search?q=" + query);
// Setup connection properties (this doesn't open the connection)
URLConnection connection = url.openConnection();
connection.setRequestProperty("Accept-Charset", "UTF-8");
// Actually, open the HTTP connection
connection.connect();
// Setup a reader
BufferedReader reader = new BufferedReader(
new InputStreamReader(connection.getInputStream()));
// Read line by line
String line = null;
while ((line = reader.readLine()) != null) {
System.out.println (line);
}
// Close connection
reader.close();

How to consume REST in Java [duplicate]

This question already has answers here:
How do you create a REST client for Java? [closed]
(18 answers)
Closed 2 years ago.
Using Java tools,
wscompile for RPC
wsimport for Document
etc..
I can use WSDL to generate the stub and Classes required to hit the SOAP Web Service.
But I have no idea how I can do the same in REST.
How can I get the Java classes required for hitting the REST Web Service.
What is the way to hit the service anyway?
Can anyone show me the way?

Working example, try this:
package restclient;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
public class NetClientGet {
public static void main(String[] args) {
try {
URL url = new URL("http://localhost:3002/RestWebserviceDemo/rest/json/product/dynamicData?size=5");//your url i.e fetch data from .
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "application/json");
if (conn.getResponseCode() != 200) {
throw new RuntimeException("Failed : HTTP Error code : "
+ conn.getResponseCode());
}
InputStreamReader in = new InputStreamReader(conn.getInputStream());
BufferedReader br = new BufferedReader(in);
String output;
while ((output = br.readLine()) != null) {
System.out.println(output);
}
conn.disconnect();
} catch (Exception e) {
System.out.println("Exception in NetClientGet:- " + e);
}
}
}

As others have said, you can do it using the lower level HTTP API, or you can use the higher level JAXRS APIs to consume a service as JSON. For example:
Client client = ClientBuilder.newClient();
WebTarget target = client.target("http://host:8080/context/rest/method");
JsonArray response = target.request(MediaType.APPLICATION_JSON).get(JsonArray.class);

Its just a 2 line of code.
import org.springframework.web.client.RestTemplate;
RestTemplate restTemplate = new RestTemplate();
YourBean obj = restTemplate.getForObject("http://gturnquist-quoters.cfapps.io/api/random", YourBean.class);
Ref. Spring.io consuming-rest

The code below will help to consume rest api via Java.
URL - end point rest
If you dont need any authentication you dont need to write the authStringEnd variable
The method will return a JsonObject with your response
public JSONObject getAllTypes() throws JSONException, IOException {
String url = "/api/atlas/types";
String authString = name + ":" + password;
String authStringEnc = new BASE64Encoder().encode(authString.getBytes());
javax.ws.rs.client.Client client = ClientBuilder.newClient();
WebTarget webTarget = client.target(host + url);
Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_JSON).header("Authorization", "Basic " + authStringEnc);
Response response = invocationBuilder.get();
String output = response.readEntity(String.class
);
System.out.println(response.toString());
JSONObject obj = new JSONObject(output);
return obj;
}

Just make an http request to the required URL with correct query string, or request body.
For example you could use java.net.HttpURLConnection and then consume via connection.getInputStream(), and then covnert to your objects.
In spring there is a restTemplate that makes it all a bit easier.

If you also need to convert that xml string that comes as a response to the service call, an x object you need can do it as follows:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import javax.xml.bind.JAXB;
import javax.xml.bind.JAXBException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.CharacterData;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
public class RestServiceClient {
// http://localhost:8080/RESTfulExample/json/product/get
public static void main(String[] args) throws ParserConfigurationException,
SAXException {
try {
URL url = new URL(
"http://localhost:8080/CustomerDB/webresources/co.com.mazf.ciudad");
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setRequestProperty("Accept", "application/xml");
if (conn.getResponseCode() != 200) {
throw new RuntimeException("Failed : HTTP error code : "
+ conn.getResponseCode());
}
BufferedReader br = new BufferedReader(new InputStreamReader(
(conn.getInputStream())));
String output;
Ciudades ciudades = new Ciudades();
System.out.println("Output from Server .... \n");
while ((output = br.readLine()) != null) {
System.out.println("12132312");
System.err.println(output);
DocumentBuilder db = DocumentBuilderFactory.newInstance()
.newDocumentBuilder();
InputSource is = new InputSource();
is.setCharacterStream(new StringReader(output));
Document doc = db.parse(is);
NodeList nodes = ((org.w3c.dom.Document) doc)
.getElementsByTagName("ciudad");
for (int i = 0; i < nodes.getLength(); i++) {
Ciudad ciudad = new Ciudad();
Element element = (Element) nodes.item(i);
NodeList name = element.getElementsByTagName("idCiudad");
Element element2 = (Element) name.item(0);
ciudad.setIdCiudad(Integer
.valueOf(getCharacterDataFromElement(element2)));
NodeList title = element.getElementsByTagName("nomCiudad");
element2 = (Element) title.item(0);
ciudad.setNombre(getCharacterDataFromElement(element2));
ciudades.getPartnerAccount().add(ciudad);
}
}
for (Ciudad ciudad1 : ciudades.getPartnerAccount()) {
System.out.println(ciudad1.getIdCiudad());
System.out.println(ciudad1.getNombre());
}
conn.disconnect();
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static String getCharacterDataFromElement(Element e) {
Node child = e.getFirstChild();
if (child instanceof CharacterData) {
CharacterData cd = (CharacterData) child;
return cd.getData();
}
return "";
}
}
Note that the xml structure that I expected in the example was as follows:
<ciudad><idCiudad>1</idCiudad><nomCiudad>BOGOTA</nomCiudad></ciudad>

Look at Jersey. Again, REST is all about the data. And a tutorial here

JAX-RS but you can also use regular DOM that comes with standard Java

From your question its not clear whether you are using any frameworks.For REST you will be getting an WADL & Apache CXF recently added support for WADL-first development of REST services.Please go through http://cxf.apache.org/docs/index.html

You can able to consume a Restful Web service in Spring using RestTemplate.class.
Example :
public class Application {
public static void main(String args[]) {
RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> call= restTemplate.getForEntity("http://localhost:8080/SpringExample/hello",String.class);
System.out.println(call.getBody())
}
}
Reference

Apache Http Client APIs are very commonly used for calling HTTP Rest services.
Here is one of example of consuming HTTP GET call.
import java.io.IOException;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.impl.client.HttpClientBuilder;
public class CallHTTPGetService {
public static void main(String[] args) throws ClientProtocolException, IOException {
HttpClient client = HttpClientBuilder.create().build();
HttpUriRequest httpUriRequest = new HttpGet("URL");
HttpResponse response = client.execute(httpUriRequest);
System.out.println(response);
}
}
Use following maven dependency if using Maven project.
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.1</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpmime -->
<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpmime</artifactId>
<version>4.5.1</version>
</dependency>