Add public models for errors

src/main/java/com/stripe/exception/CardException.java

@@ -1,5 +1,8 @@
 package com.stripe.exception;
 
+import lombok.Getter;
+
+@Getter
 public class CardException extends StripeException {
   private static final long serialVersionUID = 2L;
 
@@ -17,16 +20,4 @@ public CardException(String message, String requestId, String code, String param
     this.declineCode = declineCode;
     this.charge = charge;
   }
-
-  public String getParam() {
-    return param;
-  }
-
-  public String getDeclineCode() {
-    return declineCode;
-  }
-
-  public String getCharge() {
-    return charge;
-  }
 }

src/main/java/com/stripe/exception/InvalidRequestException.java

@@ -1,5 +1,8 @@
 package com.stripe.exception;
 
+import lombok.Getter;
+
+@Getter
 public class InvalidRequestException extends StripeException {
   private static final long serialVersionUID = 2L;
 
@@ -10,8 +13,4 @@ public InvalidRequestException(String message, String param, String requestId, S
     super(message, requestId, code, statusCode, e);
     this.param = param;
   }
-
-  public String getParam() {
-    return param;
-  }
 }

src/main/java/com/stripe/exception/SignatureVerificationException.java

@@ -1,5 +1,8 @@
 package com.stripe.exception;
 
+import lombok.Getter;
+
+@Getter
 public class SignatureVerificationException extends StripeException {
   private static final long serialVersionUID = 2L;
 
@@ -9,8 +12,4 @@ public SignatureVerificationException(String message, String sigHeader) {
     super(message, null, null, 0);
     this.sigHeader = sigHeader;
   }
-
-  public String getSigHeader() {
-    return sigHeader;
-  }
 }

src/main/java/com/stripe/exception/StripeException.java

@@ -1,8 +1,20 @@
 package com.stripe.exception;
 
+import com.stripe.model.StripeError;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
 public abstract class StripeException extends Exception {
   private static final long serialVersionUID = 2L;
 
+  /**
+   * The error resource returned by Stripe's API that caused the exception.
+   */
+  @Setter
+  StripeError stripeError;
+
   private String code;
   private String requestId;
   private Integer statusCode;
@@ -22,18 +34,6 @@ public StripeException(String message, String requestId, String code, Integer st
     this.statusCode = statusCode;
   }
 
-  public String getCode() {
-    return code;
-  }
-
-  public String getRequestId() {
-    return requestId;
-  }
-
-  public Integer getStatusCode() {
-    return statusCode;
-  }
-
   /**
    * Returns a description of the exception, including the HTTP status code and request ID (if
    * applicable).

src/main/java/com/stripe/exception/oauth/OAuthException.java

@@ -1,13 +1,24 @@
 package com.stripe.exception.oauth;
 
 import com.stripe.exception.StripeException;
+import com.stripe.model.oauth.OAuthError;
+
+import lombok.Getter;
+import lombok.Setter;
 
 /**
  * Base parent class for all OAuth exceptions.
  */
+@Getter
 public class OAuthException extends StripeException {
   private static final long serialVersionUID = 2L;
 
+  /**
+   * The error resource returned by Stripe's OAuth API that caused the exception.
+   */
+  @Setter
+  OAuthError oauthError;
+
   public OAuthException(String code, String description, String requestId, Integer statusCode,
       Throwable e) {
     super(description, requestId, code, statusCode, e);

src/main/java/com/stripe/model/StripeError.java

@@ -0,0 +1,62 @@
+package com.stripe.model;
+
+import com.google.gson.annotations.SerializedName;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+@EqualsAndHashCode(callSuper = false)
+public class StripeError extends StripeObject {
+  /** For card errors, the ID of the failed charge. */
+  @SerializedName("charge")
+  String charge;
+
+  /**
+   * For some errors that could be handled programmatically, a short string indicating the [error
+   * code](/docs/error-codes) reported.
+   */
+  @SerializedName("code")
+  String code;
+
+  /**
+   * For card errors resulting from a card issuer decline, a short string indicating the [card
+   * issuer's reason for the decline](/docs/declines#issuer-declines) if they provide one.
+   */
+  @SerializedName("decline_code")
+  String declineCode;
+
+  /** A URL to more information about the [error code](/docs/error-codes) reported. */
+  @SerializedName("doc_url")
+  String docUrl;
+
+  /**
+   * A human-readable message providing more details about the error. For card errors, these
+   * messages can be shown to your users.
+   */
+  @SerializedName("message")
+  String message;
+
+  /**
+   * If the error is parameter-specific, the parameter related to the error. For example, you can
+   * use this to display a message near the correct form field.
+   */
+  @SerializedName("param")
+  String param;
+
+  // TODO: add `payment_method`
+
+  /**
+   * The source object for errors returned on a request involving a source.
+   */
+  @SerializedName("source")
+  ExternalAccount source;
+
+  /**
+   * The type of error returned. One of `api_connection_error`, `api_error`, `authentication_error`,
+   * `card_error`, `idempotency_error`, `invalid_request_error`, or `rate_limit_error`
+   */
+  @SerializedName("type")
+  String type;
+}

src/main/java/com/stripe/model/oauth/OAuthError.java

@@ -0,0 +1,15 @@
+package com.stripe.model.oauth;
+
+import com.stripe.model.StripeObject;
+
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+@EqualsAndHashCode(callSuper = false)
+public class OAuthError extends StripeObject {
+  String error;
+  String errorDescription;
+}