feat: ability to change rest client credentials

Author: Insmael

src/main/java/com/cryptomarket/sdk/HMAC.java

@@ -25,6 +25,10 @@ public HMAC(String apiKey, String apiSecret, Integer window) {
     this.window = window;
   }
 
+  public Integer getWindow() {
+    return window;
+  }
+
   public String getCredential(String method, String body, String url) {
     String timestamp = String.format("%d", System.currentTimeMillis());
     String message = new StringBuffer()

src/main/java/com/cryptomarket/sdk/rest/CloseableHttpClient.java

@@ -9,6 +9,13 @@
 
 public interface CloseableHttpClient extends Closeable {
 
+  /**
+   * Changes the user credentials used for authentication in calls
+   * @param apiKey the user public key used in new calls
+   * @param apiSecret the user secret key used in new calls
+   */
+  public void changeCredentials(String apiKey, String apiSecret);
+
   /**
    * Does an http get without authentication
    *

src/main/java/com/cryptomarket/sdk/rest/CryptomarketRestClientImpl.java

@@ -53,7 +53,7 @@ public class CryptomarketRestClientImpl implements CryptomarketRestClient {
   Adapter adapter = new Adapter();
 
   public CryptomarketRestClientImpl(String apiKey, String apiSecret) {
-    this(apiKey,  apiSecret, HttpClients.createDefault());
+    this(apiKey, apiSecret, HttpClients.createDefault());
   }
 
   public CryptomarketRestClientImpl(String apiKey, String apiSecret,
@@ -71,6 +71,11 @@ public CryptomarketRestClientImpl(org.apache.http.impl.client.CloseableHttpClien
     this("", "", client);
   }
 
+  @Override
+  public void changeCredentials(String apiKey, String apiSecret) {
+    httpClient.changeCredentials(apiKey, apiSecret);
+  }
+
   // PUBLIC
 
   @Override

src/main/java/com/cryptomarket/sdk/rest/HttpClientImpl.java

@@ -98,6 +98,11 @@ public HttpClientImpl(org.apache.http.impl.client.CloseableHttpClient client, St
     this.apiVersion = apiVersion;
   }
 
+  @Override
+  public void changeCredentials(String apiKey, String apiSecret) {
+    this.hmac = new HMAC(apiKey, apiSecret, hmac.getWindow());
+  }
+
   public void close() throws IOException {
     client.close();
   }