Add token revocation endpoint

Author: aianus

src/main/java/com/coinbase/api/Coinbase.java

@@ -932,6 +932,17 @@ public String getAuthCode(OAuthCodeRequest request)
      */
     public OAuthTokensResponse getTokens(String clientId, String clientSecret, String authCode, String redirectUri) throws UnauthorizedDeviceException, CoinbaseException, IOException;
 
+    /**
+     * Revoke current access token.
+     *
+     * This client must have previously been initialized with an access token.
+     * Future methods requiring authentication will fail.
+     *
+     * @throws CoinbaseException
+     * @throws IOException
+     */
+    public void revokeToken() throws CoinbaseException, IOException;
+
     /**
      * Refresh OAuth tokens
      *

src/main/java/com/coinbase/api/CoinbaseImpl.java

@@ -64,6 +64,7 @@
 import com.coinbase.api.entity.ReportsResponse;
 import com.coinbase.api.entity.Request;
 import com.coinbase.api.entity.Response;
+import com.coinbase.api.entity.RevokeTokenRequest;
 import com.coinbase.api.entity.Token;
 import com.coinbase.api.entity.TokenResponse;
 import com.coinbase.api.entity.Transaction;
@@ -1038,6 +1039,29 @@ public OAuthTokensResponse getTokens(String clientId, String clientSecret, Strin
         return post(tokenUrl, request, OAuthTokensResponse.class);
     }
 
+    @Override
+    public void revokeToken() throws CoinbaseException, IOException {
+
+        if (_accessToken == null) {
+            throw new CoinbaseException(
+                "This client must have been initialized with an access token in order to call revokeToken()"
+            );
+        }
+
+        URL revokeTokenUrl;
+        try {
+            revokeTokenUrl = new URL(_baseOAuthUrl, "revoke");
+        } catch (MalformedURLException ex) {
+            throw new AssertionError(ex);
+        }
+
+        RevokeTokenRequest request = new RevokeTokenRequest();
+        request.setToken(_accessToken);
+
+        post(revokeTokenUrl, request, Response.class);
+        _accessToken = null;
+    }
+
     @Override
     public OAuthTokensResponse refreshTokens(String clientId, String clientSecret, String refreshToken)
             throws CoinbaseException, IOException {

src/main/java/com/coinbase/api/entity/RevokeTokenRequest.java

@@ -0,0 +1,17 @@
+package com.coinbase.api.entity;
+
+import java.io.Serializable;
+
+public class RevokeTokenRequest implements Serializable {
+    private static final long serialVersionUID = -1445803678709058848L;
+
+    private String token;
+
+    public String getToken() {
+        return token;
+    }
+
+    public void setToken(String token) {
+        this.token = token;
+    }
+}