Add ability to suppress messages from stacktrace (#1104)

* Add ability to suppress messages from stacktrace
Update README.md

* Rename ShortenedThrowableConverter.SANITIZE to OMIT_THROWABLE_MESSAGE

add unit test

* Use a BasicMarkerFactory to construct OMIT_THROWABLE_MESSAGE marker

---------

Co-authored-by: Patrick Barry <[email protected]>

Author: philsttr

README.md

@@ -66,8 +66,9 @@ The structure of the output, and the data it contains, is fully configurable.
     * [Omit Common Frames](#omit-common-frames)
     * [Truncate after Regex](#truncate-after-regex)
     * [Exclude Frames per Regex](#exclude-frames-per-regex)
+    * [Omit Throwable Messages](#omit-throwable-messages)
     * [Maximum Depth per Throwable](#maximum-depth-per-throwable)
-    * [Maximum Trace Size (bytes)](#maximum-trace-size)
+    * [Maximum Trace Size (bytes)](#maximum-trace-size-bytes)
     * [Classname Shortening](#classname-shortening)
     * [Custom Line Separator](#custom-line-separator)
     * [Root Cause First](#root-cause-first)
@@ -2124,6 +2125,47 @@ Alternatively, multiple exclusion patterns can be specified at once using the `<
 Using the `<exclusions>` configuration option can be useful when using an environment variable to specify the actual patterns at deployment time.
 
 
+### Omit Throwable Messages
+
+To omit throwable messages from stacktraces, add the `ShortenedThrowableConverter.OMIT_THROWABLE_MESSAGE` marker
+to log statements.
+
+Consider the following stacktrace (without omitting messages):
+
+```
+Exception in thread "main" com.myproject.module.MyProjectFooBarException: Customer ssn of 12345678 was not registered
+    at com.myproject.module.MyProject.anotherMethod(MyProject.java:19)
+    at com.myproject.module.MyProject.someMethod(MyProject.java:12)
+    at com.myproject.module.MyProject.main(MyProject.java:8)
+Caused by: java.lang.ArithmeticException: Could not generate userId for Customer with phone number 111-111-1111
+    at org.apache.commons.lang3.math.Fraction.getFraction(Fraction.java:143)
+    at com.myproject.module.MyProject.anotherMethod(MyProject.java:17)
+    ... 2 more
+```
+
+If the `ShortenedThrowableConverter.OMIT_THROWABLE_MESSAGE` marker is used when logging the above throwable,
+then the `ShortenedThrowableConverter` will omit all messages in the stacktrace.
+
+For example, the following code:
+
+```java
+    logger.error(OMIT_THROWABLE_MESSAGE, "An exception was thrown but I want to make sure no customer data is shown in stacktrace", e);
+```
+
+will produce:
+
+```
+Exception in thread "main" com.myproject.module.MyProjectFooBarException:
+    at com.myproject.module.MyProject.anotherMethod(MyProject.java:19)
+    at com.myproject.module.MyProject.someMethod(MyProject.java:12)
+    at com.myproject.module.MyProject.main(MyProject.java:8)
+Caused by: java.lang.ArithmeticException: 
+    at org.apache.commons.lang3.math.Fraction.getFraction(Fraction.java:143)
+    at com.myproject.module.MyProject.anotherMethod(MyProject.java:17)
+    ... 2 more
+```
+
+This enables devs to still see the type of exception thrown and where it occurred, **without** exposing sensitive data.
 
 ### Maximum Depth per Throwable
 
@@ -2843,7 +2885,7 @@ The provider name is the xml element name to use when configuring. Each provider
 
 
 
-### Providers for AccessEvents  
+### Providers for AccessEvents
 
 The [common providers mentioned above](#providers-common-to-loggingevents-and-accessevents), and the providers listed in the table below, are available for _AccessEvents_.
 The provider name is the xml element name to use when configuring. Each provider's configuration properties are shown, with default configuration values in parenthesis.