Add Conditional Helpers to DruidException / InvalidInput (#16470)

Adds versions of 

DruidException.defensive(String, Object...)
InvalidInput.exception(String, Object...)
InvalidInput.exception(Throwable, String, Object...)

the versions add a boolean as the first arg and only create and throw
an exception if it's false. It can be used similar to
Preconditions.checkState/checkArgument

processing/src/main/java/org/apache/druid/error/DruidException.java

@@ -47,7 +47,7 @@ import java.util.Map;
  * no change should occur.
  * <p>
  * <h3>Notes about exception messages:</h3>
- *
+ * <p>
  * Firstly, exception messages should always be written with the notions from the style conventions covered in
  * {@code dev/style-conventions.md}.  Whenever possible, we should also try to provide an action to take to resolve
  * the issue.
@@ -176,6 +176,22 @@ public class DruidException extends RuntimeException
     return defensive().build(format, args);
   }
 
+  /**
+   * Build a "defensive" exception, this is an exception that should never actually be triggered. Throw to
+   * allow messages to be seen by developers
+   *
+   * @param condition - boolean condition to validate
+   * @param msg - passed through to InvalidInput.exception()
+   * @param args - passed through to InvalidInput.exception()
+   */
+  @SuppressWarnings("unused")
+  public static void conditionalDefensive(boolean condition, String msg, Object... args)
+  {
+    if (!condition) {
+      throw defensive(msg, args);
+    }
+  }
+
   private final Persona targetPersona;
   private final Category category;
   private final String errorCode;

processing/src/main/java/org/apache/druid/error/InvalidInput.java

@@ -35,6 +35,37 @@ public class InvalidInput extends BaseFailure
     return DruidException.fromFailure(new InvalidInput(t, msg, args));
   }
 
+  /**
+   * evalues a condition. If it's false, it throws the appropriate DruidException
+   *
+   * @param condition - boolean condition to validate
+   * @param msg - passed through to DruidException.exception()
+   * @param args - passed through to DruidException.exception()
+   */
+  public static void conditionalException(boolean condition, String msg, Object... args)
+  {
+    if (!condition) {
+      throw exception(msg, args);
+    }
+  }
+
+  /**
+   * evalues a condition. If it's false, it throws the appropriate DruidException with a given cause
+   *
+   * @param condition - boolean condition to validate
+   * @param t - throwable to pass to InvalidInput.exception()
+   * @param msg - passed through to InvalidInput.exception()
+   * @param args - passed through to InvalidInput.exception()
+   */
+
+  public static void conditionalException(boolean condition, Throwable t, String msg, Object... args)
+  {
+    if (!condition) {
+      throw exception(t, msg, args);
+    }
+  }
+
+
   public InvalidInput(
       Throwable t,
       String msg,

processing/src/test/java/org/apache/druid/error/InvalidInputTest.java

@@ -0,0 +1,50 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.druid.error;
+
+
+import org.junit.Test;
+
+public class InvalidInputTest
+{
+  @Test
+  public void testConditionalNoThrow()
+  {
+    InvalidInput.conditionalException(true, "This should not throw");
+  }
+
+  @Test(expected = DruidException.class)
+  public void testConditionalThrow()
+  {
+    InvalidInput.conditionalException(false, "This should throw");
+  }
+
+  @Test
+  public void testConditionalNoThrowWithCause()
+  {
+    InvalidInput.conditionalException(true, new RuntimeException(), "This should not throw");
+  }
+
+  @Test(expected = DruidException.class)
+  public void testConditionalThrowWithCause()
+  {
+    InvalidInput.conditionalException(false, new RuntimeException(), "This should throw");
+  }
+}