Transforming a PayPal curl request to an http request in Java

Question

On the PayPal website, all the example calls are done using curl. Easy to repeat using CURL under Linux, but I would like to use Java to make these calls.

E.g., suppose to have the call:

curl -v https://api.sandbox.paypal.com/v1/payments/payment \
-H 'Content-Type: application/json' \
-H 'Authorization: Bearer <Access-Token>' \
-d '{
  "intent":"sale",
  "redirect_urls":{
    "return_url":"http://example.com/your_redirect_url.html",
    "cancel_url":"http://example.com/your_cancel_url.html"
  },
  "payer":{
    "payment_method":"paypal"
  },
  "transactions":[
    {
      "amount":{
        "total":"7.47",
        "currency":"USD"
      }
    }
  ]
}'

Suppose that I have the value for <Access-Token> that has to be set, how can I convert the previous string into an http request to get an answer from PayPal using Java and no CURL?

Right now I did something like the following to the an HttpURLConnection to the URL:

private HttpURLConnection createPOSTHttpURLConnection(final URL url) throws IOException {
        final HttpURLConnection connection = (HttpURLConnection) url.openConnection();

        connection.setRequestMethod("POST");
        connection.setUseCaches(false);
        connection.setDoInput(true);
        connection.setDoOutput(true);

        connection.setRequestProperty("User-Agent", "Mozilla/4.0");
        return connection;
    }

In my main I do as follows:

final HttpURLConnection connection = createPOSTHttpURLConnection(url);

connection.setRequestProperty("Authorization", "Bearer <Access-Token>");//replaced with a real value
connection.setRequestProperty("Content-Type", "application/json");
        final String jsonData = "{ \"intent\":\"sale\",  \"redirect_urls\":{    \"return_url\":\"http://example.com/your_redirect_url.html\",    \"cancel_url\":\"http://example.com/your_cancel_url.html\" }, \"payer\":{    \"payment_method\":\"paypal\"  },  \"transactions\":[    {      \"amount\":{        \"total\":\"7.47\",        \"currency\":\"USD\"}}]}";

connection.setFixedLengthStreamingMode(jsonData.length());

// get the output stream to POST to.
try(final DataOutputStream output = new DataOutputStream(connection.getOutputStream())) {
        output.writeBytes(jsonData);
        output.flush();
}

final InputStream isToBeRead =  connection.getInputStream();

However, I get the following error:

Cannot read from the given URL https://api.sandbox.paypal.com/v1/payments/payment with given params and data

Tha occcurs when I try to use the InputStream:

java.net.HttpRetryException: cannot retry due to server authentication, in streaming mode
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1636)
    at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439)
    at sun.net.www.protocol.https.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:254)
    at com.sudengut.de.utils.url.HttpClient.readFromHttpURL(HttpClient.java:65)

UPDATE

Implementing Kevin Hoffman'solution I get the following result:

Server returned HTTP response code: 400 for URL: https://api.sandbox.paypal.com/v1/payments/payment
Response code:400
Response message:Bad Request

---

Implementing Garry's answer I obtain the following log:

 21:30:06.070 [main] DEBUG o.a.h.c.protocol.RequestAddCookies - CookieSpec selected: default
21:30:06.109 [main] DEBUG o.a.h.c.protocol.RequestAuthCache - Auth cache not set in the context
21:30:06.111 [main] DEBUG o.a.h.i.c.PoolingHttpClientConnectionManager - Connection request: [route: {s}->https://api.sandbox.paypal.com:443][total kept alive: 0; route allocated: 0 of 2; total allocated: 0 of 20]
21:30:06.143 [main] DEBUG o.a.h.i.c.PoolingHttpClientConnectionManager - Connection leased: [id: 0][route: {s}->https://api.sandbox.paypal.com:443][total kept alive: 0; route allocated: 1 of 2; total allocated: 1 of 20]
21:30:06.147 [main] DEBUG o.a.h.impl.execchain.MainClientExec - Opening connection {s}->https://api.sandbox.paypal.com:443
21:30:06.202 [main] DEBUG o.a.h.i.c.DefaultHttpClientConnectionOperator - Connecting to api.sandbox.paypal.com/173.0.82.78:443
21:30:06.202 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory - Connecting socket to api.sandbox.paypal.com/173.0.82.78:443 with timeout 0
21:30:06.668 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory - Enabled protocols: [TLSv1, TLSv1.1, TLSv1.2]
21:30:06.668 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory - Enabled cipher suites:[TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256, TLS_RSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_RSA_WITH_AES_128_CBC_SHA256, TLS_DHE_DSS_WITH_AES_128_CBC_SHA256, TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_128_CBC_SHA, TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA, TLS_ECDH_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_RSA_WITH_AES_128_CBC_SHA, TLS_DHE_DSS_WITH_AES_128_CBC_SHA, TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, TLS_RSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256, TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_RSA_WITH_AES_128_GCM_SHA256, TLS_DHE_DSS_WITH_AES_128_GCM_SHA256, TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_RSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA, TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA, SSL_DHE_DSS_WITH_3DES_EDE_CBC_SHA, TLS_ECDHE_ECDSA_WITH_RC4_128_SHA, TLS_ECDHE_RSA_WITH_RC4_128_SHA, SSL_RSA_WITH_RC4_128_SHA, TLS_ECDH_ECDSA_WITH_RC4_128_SHA, TLS_ECDH_RSA_WITH_RC4_128_SHA, SSL_RSA_WITH_RC4_128_MD5, TLS_EMPTY_RENEGOTIATION_INFO_SCSV]
21:30:06.669 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory - Starting handshake
21:30:07.291 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory - Secure session established
21:30:07.291 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory -  negotiated protocol: TLSv1.2
21:30:07.292 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory -  negotiated cipher suite: TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
21:30:07.292 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory -  peer principal: CN=api.sandbox.paypal.com, OU=PayPal Production, O="PayPal, Inc.", L=San Jose, ST=California, C=US
21:30:07.292 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory -  peer alternative names: [api.sandbox.paypal.com]
21:30:07.293 [main] DEBUG o.a.h.c.s.SSLConnectionSocketFactory -  issuer principal: CN=VeriSign Class 3 Secure Server CA - G3, OU=Terms of use at https://www.verisign.com/rpa (c)10, OU=VeriSign Trust Network, O="VeriSign, Inc.", C=US
21:30:07.306 [main] DEBUG o.a.h.i.c.DefaultHttpClientConnectionOperator - Connection established 192.168.178.22:45213<->173.0.82.78:443
21:30:07.306 [main] DEBUG o.a.h.impl.execchain.MainClientExec - Executing request POST /v1/payments/payment HTTP/1.1
21:30:07.306 [main] DEBUG o.a.h.impl.execchain.MainClientExec - Proxy auth state: UNCHALLENGED
21:30:07.310 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> POST /v1/payments/payment HTTP/1.1
21:30:07.310 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> Content-Type: application/json
21:30:07.310 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> Authorization: Bearer A015TlBaYzfyFSUt9rVin-Lnltn6JuQLA968RyGGC8h.Zds
21:30:07.310 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> Content-Length: 254
21:30:07.311 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> Host: api.sandbox.paypal.com
21:30:07.311 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> Connection: Keep-Alive
21:30:07.311 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> User-Agent: Apache-HttpClient/4.5 (Java/1.8.0_25)
21:30:07.311 [main] DEBUG org.apache.http.headers - http-outgoing-0 >> Accept-Encoding: gzip,deflate
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "POST /v1/payments/payment HTTP/1.1[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "Content-Type: application/json[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "Authorization: Bearer A015TlBaYzfyFSUt9rVin-Lnltn6JuQLA968RyGGC8h.Zds[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "Content-Length: 254[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "Host: api.sandbox.paypal.com[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "Connection: Keep-Alive[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "User-Agent: Apache-HttpClient/4.5 (Java/1.8.0_25)[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "Accept-Encoding: gzip,deflate[\r][\n]"
21:30:07.311 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "[\r][\n]"
21:30:07.312 [main] DEBUG org.apache.http.wire - http-outgoing-0 >> "{ "intent":"sale","redirect_urls":{ "return_url":"http://example.com/your_redirect_url.html", "cancel_url ":"http://example.com/your_cancel_url.html" }, "payer":{"payment_method":"paypal"},"transactions":[{ "amount":{ "total":"7.47", "currency":"USD"}}]}"
21:30:07.663 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "HTTP/1.1 400 Bad Request[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Date: Wed, 29 Jul 2015 19:30:07 GMT[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Server: Apache[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "PROXY_SERVER_INFO: host=slcsbplatformapiserv3001.slc.paypal.com;threadId=205[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Paypal-Debug-Id: 3780624b824ed[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "CORRELATION-ID: 3780624b824ed[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Content-Language: *[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Connection: close[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Connection: close[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Content-Length: 404[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Set-Cookie: X-PP-SILOVER=name%3DSANDBOX3.API.1%26silo_version%3D880%26app%3Dplatformapiserv%26TIME%3D3207182677; domain=.paypal.com; path=/; Secure; HttpOnly[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Set-Cookie: X-PP-SILOVER=; Expires=Thu, 01 Jan 1970 00:00:01 GMT[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Vary: Authorization[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "Content-Type: application/json[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "[\r][\n]"
21:30:07.664 [main] DEBUG org.apache.http.wire - http-outgoing-0 << "{"name":"VALIDATION_ERROR","details":[{"field":"redirect_urls.cancel_url ","issue":"This field name is not defined for this resource type"},{"field":"redirect_urls.cancel_url","issue":"This field required when payment_method is 'paypal'"}],"message":"Invalid request - see details","information_link":"https://developer.paypal.com/webapps/developer/docs/api/#VALIDATION_ERROR","debug_id":"3780624b824ed"}"
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << HTTP/1.1 400 Bad Request
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Date: Wed, 29 Jul 2015 19:30:07 GMT
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Server: Apache
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << PROXY_SERVER_INFO: host=slcsbplatformapiserv3001.slc.paypal.com;threadId=205
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Paypal-Debug-Id: 3780624b824ed
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << CORRELATION-ID: 3780624b824ed
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Content-Language: *
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Connection: close
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Connection: close
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Content-Length: 404
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Set-Cookie: X-PP-SILOVER=name%3DSANDBOX3.API.1%26silo_version%3D880%26app%3Dplatformapiserv%26TIME%3D3207182677; domain=.paypal.com; path=/; Secure; HttpOnly
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Set-Cookie: X-PP-SILOVER=; Expires=Thu, 01 Jan 1970 00:00:01 GMT
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Vary: Authorization
21:30:07.669 [main] DEBUG org.apache.http.headers - http-outgoing-0 << Content-Type: application/json
21:30:07.681 [main] DEBUG o.a.h.c.p.ResponseProcessCookies - Cookie accepted [X-PP-SILOVER="name%3DSANDBOX3.API.1%26silo_version%3D880%26app%3Dplatformapiserv%26TIME%3D3207182677", version:0, domain:paypal.com, path:/, expiry:null]
21:30:07.684 [main] WARN  o.a.h.c.p.ResponseProcessCookies - Invalid cookie header: "Set-Cookie: X-PP-SILOVER=; Expires=Thu, 01 Jan 1970 00:00:01 GMT". Invalid 'expires' attribute: Thu, 01 Jan 1970 00:00:01 GMT

If I implement this question with some more info, I see that the given cookie is appended and doesn't replace the one with a missing expiration date. Just run:

import java.time.Instant;
import java.time.LocalDate;
import java.time.ZoneId;
import java.time.temporal.ChronoUnit;

import java.util.Date;

import org.apache.http.HttpResponse;
import org.apache.http.client.CookieStore;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.CookieSpecs;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.cookie.BasicClientCookie;
import org.apache.http.protocol.HTTP;

public class GarrysSolution {

    public static void main(final String[] args) {

        String accessToken = "A-valid-token";
        String jsonString =
            "{ \"intent\":\"sale\",\"redirect_urls\":{ \"return_url\":\"http://example.com/your_redirect_url.html\", \"cancel_url \":\"http://example.com/your_cancel_url.html\" }, \"payer\":{\"payment_method\":\"paypal\"},\"transactions\":[{ \"amount\":{ \"total\":\"7.47\", \"currency\":\"USD\"}}]}";

        BasicCookieStore cookieStore = new BasicCookieStore();
        BasicClientCookie cookie = new BasicClientCookie("JSESSIONID", "1234");
        cookie.setDomain(".paypal.com");
        cookie.setPath("/");

        LocalDate expirationDate = LocalDate.now().plus(100L, ChronoUnit.DAYS);
        Instant instant = Instant.from(expirationDate.atStartOfDay(ZoneId.of("GMT")));
        cookie.setExpiryDate(Date.from(instant));
        cookie.setCreationDate(Date.from(Instant.now()));
        cookieStore.addCookie(cookie);

        RequestConfig globalConfig = RequestConfig.custom().setCookieSpec(CookieSpecs.NETSCAPE).build();        HttpClientContext context = HttpClientContext.create();
        context.setCookieStore(cookieStore);

        HttpClient httpClient = HttpClients.custom().setDefaultRequestConfig(globalConfig)
                                           .setDefaultCookieStore(cookieStore).build();

        HttpPost httpPost = new HttpPost("https://api.sandbox.paypal.com/v1/payments/payment");
        httpPost.setHeader("Content-Type", "application/json");
        httpPost.setHeader("Authorization", "Bearer " + accessToken);

        StringEntity entity = new StringEntity(jsonString, HTTP.UTF_8);
        entity.setContentType("application/json");
        httpPost.setEntity(entity);
        try {
            HttpResponse httpResponse = httpClient.execute(httpPost, context);

            System.out.println("\n\n" + context.getCookieStore().getCookies());

            System.out.println("\n\n" + httpResponse.getStatusLine().getStatusCode() + "/"
                    + httpResponse.getStatusLine().getReasonPhrase());
        } catch (Exception e) {
            System.err.println(e.getMessage());
        }

    }

}

and we see the following cookies from the context:

[[version: 0][name: JSESSIONID][value: 1234][domain: .paypal.com][path: /][expiry: Fri Nov 06 01:00:00 CET 2015], [version: 0][name: X-PP-SILOVER][value: name%3DSANDBOX3.API.1%26silo_version%3D880%26app%3Dplatformapiserv%26TIME%3D2370156885][domain: .paypal.com][path: /][expiry: null]]

So I guess that the problem can be solved by setting the expiration date to the proper cookie

Answer 1

The code is swallowing the exception (in the try block with no catch) that is being thrown to indicate an HTTP error 401 (unauthorized) is occurring. This is probably due to an invalid access token. The code then tries to read the HTTP response, and that fails (since there is no response due to the 401 error) and throws the exception which is being printed to the screen.

Is it possible the access token had expired by the time you got your code set up?

I got the following code (below) to work successfully with PayPal with a valid access token. There are some slight differences from your code (no separate methods; using HttpsURLConnection rather than HttpUrlConnection; removed some un-needed headers; etc.), but none of these changes made it work alone - they just tightened it up a bit and ensured it printed a proper error message when something went wrong. Then once I supplied a valid access token it worked successfully. I imagine you are aware that the angle brackets < >around the access token must be removed, or you would never have gotten the curl approach to work.

Also, keep in mind this is just example code - production code should move the close statements into finally blocks, or go back to the try-with-resources approach you had initially.

import java.io.BufferedReader; 
import java.io.InputStreamReader;
import java.io.DataOutputStream; 
import java.net.URL;             
import javax.net.ssl.HttpsURLConnection;

public class TestHttpsPost {

    public static void main(String[] args) throws Exception {

        // Uncomment one of these next two lines:
        URL url = new URL("https://api.sandbox.paypal.com/v1/payments/payment");
        //URL url = new URL("https://httpbin.org/post"); // good for testing

        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setDoInput(true);
        connection.setDoOutput(true);

        // Change this to a valid token:
        connection.setRequestProperty("Authorization", "Bearer <Access-Token>");
        connection.setRequestProperty("Content-Type", "application/json");
        String jsonData = "{ \"intent\":\"sale\",  \"redirect_urls\":{        \"return_url\":\"http://example.com/your_redirect_url.html\",    \"cancel_url    \":\"http://example.com/your_cancel_url.html\" }, \"payer\":{    \"payment_method\":\"paypal\"  },  \"transactions\":[    {          \"amount\":{        \"total\":\"7.47\",        \"currency\":\"USD\"}}]}";

        try {
            // Post the data:
            DataOutputStream output = new DataOutputStream(connection.getOutputStream());
            output.writeBytes(jsonData);
            output.close();

            // Read the response:
            BufferedReader reader = new BufferedReader(new InputStreamReader(
              connection.getInputStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            reader.close();
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }

        System.out.println("Response code:" + connection.getResponseCode());
        System.out.println("Response message:" + connection.getResponseMessage());
    }
}

Answer 2

You might want to try Apache HTTPClient like below:

BasicCookieStore cookieStore = new BasicCookieStore();
BasicClientCookie cookie = new BasicClientCookie("JSESSIONID", "1234");
cookie.setDomain(".paypal.com");
cookie.setPath("/");
cookieStore.addCookie(cookie);

String accessToken = "your_access_token";
String jsonString = "{ \"intent\":\"sale\",\"redirect_urls\":{ \"return_url\":\"http://example.com/your_redirect_url.html\", \"cancel_url \":\"http://example.com/your_cancel_url.html\" }, \"payer\":{\"payment_method\":\"paypal\"},\"transactions\":[{ \"amount\":{ \"total\":\"7.47\", \"currency\":\"USD\"}}]}";
HttpClient httpClient = HttpClientBuilder.create().setDefaultCookieStore(cookieStore).build();
HttpPost httpPost = new HttpPost("https://api.sandbox.paypal.com/v1/payments/payment");
httpPost.setHeader("Content-Type", "application/json");
httpPost.setHeader("Authorization", "Bearer " + accessToken);
StringEntity entity = new StringEntity(jsonString, HTTP.UTF_8);
entity.setContentType("application/json");
httpPost.setEntity(entity);
try {
    HttpResponse httpResponse = httpClient.execute(httpPost);
    System.out.println(httpResponse.getStatusLine().getStatusCode() + "/" + httpResponse.getStatusLine().getReasonPhrase());
} catch (Exception e) {
    System.err.println(e.getMessage());
}

Answer 3

I just repaste the Kevin's code after removing all the spaces under the "JsonData" variable and replacing the real token and it works fine .

import java.io.BufferedReader; 
import java.io.InputStreamReader;
import java.io.DataOutputStream; 
import java.net.URL;             
import javax.net.ssl.HttpsURLConnection;

public class TestHttpsPost {

    public static void main(String[] args) throws Exception {

        // Uncomment one of these next two lines:
        URL url = new URL("https://api.sandbox.paypal.com/v1/payments/payment");
        //URL url = new URL("https://httpbin.org/post"); // good for testing

        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        connection.setRequestMethod("POST");
        connection.setDoInput(true);
        connection.setDoOutput(true);

        // Change this to a valid token:
        connection.setRequestProperty("Authorization", "Bearer A015mK--1cz4kfmrLwEuxE9VgHIh9IwEqNvUvdlqMAByvjI");
        connection.setRequestProperty("Content-Type", "application/json");
        String jsonData = "{ \"intent\":\"sale\",\"redirect_urls\":{\"return_url\":\"http://example.com/your_redirect_url.html\",\"cancel_url\":\"http://example.com/your_cancel_url.html\"},\"payer\":{\"payment_method\":\"paypal\"},\"transactions\":[{\"amount\":{\"total\":\"7.47\",\"currency\":\"USD\"}}]}";

        try {
            // Post the data:
            DataOutputStream output = new DataOutputStream(connection.getOutputStream());
            output.writeBytes(jsonData);
            output.close();

            // Read the response:
            BufferedReader reader = new BufferedReader(new InputStreamReader(
              connection.getInputStream()));
            String line;
            while ((line = reader.readLine()) != null) {
                System.out.println(line);
            }
            reader.close();
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }

        System.out.println("Response code:" + connection.getResponseCode());
        System.out.println("Response message:" + connection.getResponseMessage());
    }
}

OUTPUT

C:\Users\Desktop\Java>java TestHttpsPost
{"id":"PAY-0SM99950896487827KW4ZAZA","create_time":"2015-07-30T02:48:04Z","updat
e_time":"2015-07-30T02:48:04Z","state":"created","intent":"sale","payer":{"payme
nt_method":"paypal","payer_info":{"shipping_address":{}}},"transactions":[{"amou
nt":{"total":"7.47","currency":"USD","details":{"subtotal":"7.47"}},"related_res
ources":[]}],"links":[{"href":"https://api.sandbox.paypal.com/v1/payments/paymen
t/PAY-0SM99950896487827KW4ZAZA","rel":"self","method":"GET"},{"href":"https://ww
w.sandbox.paypal.com/cgi-bin/webscr?cmd=_express-checkout&token=EC-8F164253W5887
9412","rel":"approval_url","method":"REDIRECT"},{"href":"https://api.sandbox.pay
pal.com/v1/payments/payment/PAY-0SM99950896487827KW4ZAZA/execute","rel":"execute
","method":"POST"}]}
Response code:201
Response message:Created