From f59f4c5c0fd4201e9e5a81ed26f853e99226725c Mon Sep 17 00:00:00 2001
From: Robert von Burg <eitch@eitchnet.ch>
Date: Fri, 2 Oct 2015 08:19:07 +0200
Subject: [PATCH] [New] Added ExceptionHelper.getExceptionMessageWithCauses()
 and tests

---
 .../utils/helper/ExceptionHelper.java         | 49 ++++++++++++-------
 .../utils/helper/ExceptionHelperTest.java     | 46 +++++++++++++++++
 2 files changed, 76 insertions(+), 19 deletions(-)
 create mode 100644 src/test/java/ch/eitchnet/utils/helper/ExceptionHelperTest.java

diff --git a/src/main/java/ch/eitchnet/utils/helper/ExceptionHelper.java b/src/main/java/ch/eitchnet/utils/helper/ExceptionHelper.java
index cfe5166dd..916489e71 100644
--- a/src/main/java/ch/eitchnet/utils/helper/ExceptionHelper.java
+++ b/src/main/java/ch/eitchnet/utils/helper/ExceptionHelper.java
@@ -40,6 +40,29 @@ public class ExceptionHelper {
 		return StringHelper.isEmpty(t.getMessage()) ? t.getClass().getName() : t.getMessage();
 	}
 
+	/**
+	 * <p>
+	 * Returns a message for the given {@link Throwable}
+	 * </p>
+	 * 
+	 * <p>
+	 * A {@link NullPointerException} only has <code>null</code> as the message so this methods returns the class name
+	 * in such a case
+	 * </p>
+	 * 
+	 * @param t
+	 * @return
+	 */
+	public static String getExceptionMessageWithCauses(Throwable t) {
+
+		if (t.getCause() == null) {
+			return getExceptionMessage(t);
+		}
+
+		String root = getExceptionMessageWithCauses(t.getCause());
+		return getExceptionMessage(t) + "\n" + root;
+	}
+
 	/**
 	 * Formats the given {@link Throwable}'s stack trace to a string
 	 * 
@@ -64,24 +87,12 @@ public class ExceptionHelper {
 	 * @return a string representation of the given {@link Throwable}'s messages including causes
 	 */
 	public static String formatExceptionMessage(Throwable t) {
-		StringBuilder sb = new StringBuilder();
-		sb.append(t.getMessage());
-		appendCause(sb, t);
-		return sb.toString();
+
+		if (t.getCause() == null) {
+			return getExceptionMessage(t);
+		}
+
+		String root = formatExceptionMessage(t.getCause());
+		return getExceptionMessage(t) + "\ncause:\n" + root;
 	}
-
-	private static void appendCause(StringBuilder sb, Throwable e) {
-		Throwable cause = e.getCause();
-		if (cause == null)
-			return;
-
-		sb.append("\n");
-
-		sb.append("cause:\n");
-		sb.append(cause.getMessage());
-
-		if (cause.getCause() != null)
-			appendCause(sb, cause.getCause());
-	}
-
 }
diff --git a/src/test/java/ch/eitchnet/utils/helper/ExceptionHelperTest.java b/src/test/java/ch/eitchnet/utils/helper/ExceptionHelperTest.java
new file mode 100644
index 000000000..eba21340e
--- /dev/null
+++ b/src/test/java/ch/eitchnet/utils/helper/ExceptionHelperTest.java
@@ -0,0 +1,46 @@
+package ch.eitchnet.utils.helper;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class ExceptionHelperTest {
+
+	@Test
+	public void shouldGetExceptionMsg() {
+
+		Exception e = nestedException();
+		assertEquals("Third", ExceptionHelper.getExceptionMessage(e));
+		assertEquals("Third\nSecond\nFirst", ExceptionHelper.getExceptionMessageWithCauses(e));
+	}
+
+	@Test
+	public void shouldFormatException() {
+
+		Exception e = nestedException();
+		String formatException = ExceptionHelper.formatException(e);
+		assertTrue(formatException.contains("java.lang.RuntimeException: First"));
+		assertTrue(formatException.contains("java.lang.RuntimeException: Second"));
+		assertTrue(formatException.contains("java.lang.RuntimeException: Third"));
+
+		formatException = ExceptionHelper.formatExceptionMessage(e);
+		assertEquals("Third\ncause:\nSecond\ncause:\nFirst", formatException);
+	}
+
+	private Exception nestedException() {
+		try {
+			try {
+				try {
+					throw new RuntimeException("First");
+				} catch (Exception e) {
+					throw new RuntimeException("Second", e);
+				}
+			} catch (Exception e) {
+				throw new RuntimeException("Third", e);
+			}
+		} catch (Exception e) {
+			return e;
+		}
+	}
+}