refactor: fix toString method

Author: andrei-cristea

src/test/java/org/eclipse/keyple/card/calypso/TestDtoAdapters.java

@@ -13,7 +13,7 @@
 
 import java.util.Arrays;
 import java.util.List;
-import org.eclipse.keyple.core.util.json.JsonUtil;
+import org.eclipse.keyple.core.util.HexUtil;
 import org.eclipse.keypop.card.ApduResponseApi;
 import org.eclipse.keypop.card.CardResponseApi;
 import org.eclipse.keypop.card.CardSelectionResponseApi;
@@ -57,15 +57,16 @@ public int getStatusWord() {
       return statusWord;
     }
 
-    /**
-     * Converts the APDU response into a string where the data is encoded in a json format.
-     *
-     * @return A not empty String
-     * @since 2.0.0
-     */
     @Override
     public String toString() {
-      return "APDU_RESPONSE = " + JsonUtil.toJson(this);
+      return "ApduResponseAdapter{"
+          + "apdu='"
+          + HexUtil.toHex(apdu)
+          + '\''
+          + ", statusWord='"
+          + HexUtil.toHex(statusWord)
+          + '\''
+          + '}';
     }
 
     @Override
@@ -132,6 +133,16 @@ public boolean isLogicalChannelOpen() {
       return isLogicalChannelOpen;
     }
 
+    @Override
+    public String toString() {
+      return "CardResponseAdapter{"
+          + "apduResponses="
+          + apduResponses
+          + ", isLogicalChannelOpen="
+          + isLogicalChannelOpen
+          + '}';
+    }
+
     @Override
     public boolean equals(Object o) {
       if (this == o) return true;
@@ -183,5 +194,16 @@ public boolean hasMatched() {
     public CardResponseApi getCardResponse() {
       throw new UnsupportedOperationException("hasMatched");
     }
+
+    @Override
+    public String toString() {
+      return "CardSelectionResponseAdapter{"
+          + "powerOnData='"
+          + powerOnData
+          + '\''
+          + ", selectApplicationResponse="
+          + selectApplicationResponse
+          + '}';
+    }
   }
 }