[hotfix][doc] fix typo in java doc.

flink-core/src/main/java/org/apache/flink/api/common/operators/MailboxExecutor.java

@@ -30,9 +30,9 @@
 import java.util.concurrent.RejectedExecutionException;
 
 /**
- * {@link java.util.concurrent.Executor} like interface for an build around a mailbox-based
- * execution model. {@code MailboxExecutor} can also execute downstream messages of a mailbox by
- * yielding control from the task thread.
+ * {@link java.util.concurrent.Executor} like interface for a build around a mailbox-based execution
+ * model. {@code MailboxExecutor} can also execute downstream messages of a mailbox by yielding
+ * control from the task thread.
  *
  * <p>All submission functions can be called from any thread and will enqueue the action for further
  * processing in a FIFO fashion.
@@ -218,7 +218,7 @@ void execute(
  }
 
  /**
- * This methods starts running the command at the head of the mailbox and is intended to be used
+ * This method starts running the command at the head of the mailbox and is intended to be used
  * by the mailbox thread to yield from a currently ongoing action to another command. The method
  * blocks until another command to run is available in the mailbox and must only be called from
  * the mailbox thread. Must only be called from the mailbox thread to not violate the
@@ -232,7 +232,7 @@ void execute(
  void yield() throws InterruptedException, FlinkRuntimeException;
 
  /**
- * This methods attempts to run the command at the head of the mailbox. This is intended to be
+ * This method attempts to run the command at the head of the mailbox. This is intended to be
  * used by the mailbox thread to yield from a currently ongoing action to another command. The
  * method returns true if a command was found and executed or false if the mailbox was empty.
  * Must only be called from the mailbox thread to not violate the single-threaded execution

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/mailbox/MailboxDefaultAction.java

@@ -42,8 +42,8 @@ interface Suspension {
  }
 
  /**
- * This context is a feedback interface for the default action to interact with the mailbox
- * execution. In particular it offers ways to signal that the execution of the default action
+ * This controller is a feedback interface for the default action to interact with the mailbox
+ * execution. In particular, it offers ways to signal that the execution of the default action
  * should be finished or temporarily suspended.
  */
  @Internal

flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/mailbox/TaskMailbox.java

@@ -56,7 +56,7 @@
  *
  * <p>A batch is created with {@link #createBatch()} and consumed with {@link #tryTakeFromBatch()}.
  * Note that there is no blocking {@code takeFromBatch} as batches can only be created and consumed
- * from the * mailbox thread.
+ * from the mailbox thread.
  *
  * <p>Also note that a batch can only be created in the {@link MailboxProcessor#runMailboxLoop()}. A
  * batch must not be extended in any of the consuming methods as we may run into task input
@@ -125,7 +125,7 @@ public interface TaskMailbox {
  /**
  * Creates a batch of mails that can be taken with {@link #tryTakeFromBatch()}. The batch does
  * not affect {@link #tryTake(int)} and {@link #take(int)}; that is, they return the same mails
- * even if no batch would have been created.
+ * even if no batch had been created.
  *
  * <p>The default batch is empty. Thus, this method must be invoked once before {@link
  * #tryTakeFromBatch()}.