sdk/java: expose data key for detailed error information

Closes #4065

Author: Dominic Dagradi <ddagradi@gmail.com>
Date: Tue Jul 10 16:00:15 2018 -0700
upstream:98280ffe46a68fe90d33f61bc84f81deffa8af79

Author: dominic

src/main/java/com/seq/exception/APIException.java

@@ -3,6 +3,9 @@
 import com.google.gson.annotations.SerializedName;
 import com.google.gson.annotations.Expose;
 
+import java.util.List;
+import java.util.Map;
+
 /**
  * APIException is thrown when the ledger API encounters an error handling a
  * user request. Errors could be due to user error, or due to server issues.
@@ -27,12 +30,19 @@ public class APIException extends ChainException {
   public String chainMessage;
 
   /**
-   * Additional information about the error (possibly null).
+   * Additional message about the error (possibly null).
    */
   @Expose
   public String detail;
 
   /**
+   * Additional specifics about the error, such as which
+   * action failed in a transaction, or for what reason (possibly null).
+   */
+  @Expose
+  public APIExceptionData data;
+
+    /**
    * Specifies whether the error is considered to be transient and that the
    * request should be retried.
    */
@@ -57,6 +67,37 @@ public class APIException extends ChainException {
   @Expose
   public int statusCode;
 
+  /**
+   * Additional specifics about the error, including any
+   * nested sub-errors related to individual actions.
+   */
+  public static class APIExceptionData {
+    /**
+     * Nested errors specific to individual actions in the transaction. Nested
+     * errors may contain their own API exception data object.
+     */
+    @Expose
+    public List<APIException> actions;
+
+    /**
+     * Lists fields omitted from an action.
+     */
+    @Expose
+    public List<String> missing_fields;
+
+    /**
+     * The first field with incorrect data in an action .
+     */
+    @Expose
+    public String error_fields;
+
+    /**
+     * The index in the transaction of the action with an error
+     */
+    @Expose
+    public Integer index;
+  }
+
   @Override
   public String getMessage() {
     String s = "";

src/test/java/com/seq/integration/FailureTest.java

@@ -8,7 +8,9 @@
 
 import org.junit.Test;
 
-import java.net.URL;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.ArrayList;
 
 import static org.junit.Assert.*;
 
@@ -63,4 +65,28 @@ public void testTransact() throws Exception {
     }
     throw new Exception("expecting APIException");
   }
+
+  @Test
+  public void testErrorData() throws Exception {
+    client = TestUtils.generateClient();
+    try {
+      new Transaction.Builder().addAction(
+        new Transaction.Builder.Action.Transfer()
+          .setSourceAccountId("not-real")
+          .setFlavorId("not-real")
+          .setAmount(10)
+          .setDestinationAccountId("not-real")
+      ).transact(client);
+    } catch (APIException e) {
+      assertEquals("SEQ706", e.seqCode);
+      assertEquals(1, e.data.actions.size());
+
+      APIException actionError = e.data.actions.get(0);
+      assertEquals("SEQ702", actionError.seqCode);
+      assertEquals(0, (long)actionError.data.index);
+      assertEquals("source_account_id", actionError.data.error_fields);
+      return;
+    }
+    throw new Exception("expecting APIException");
+  }
 }