Fix typos

I think that this change is too trivial to need a JIRA issue. If a JIRA issue is needed, i can create it.

Author: Jingguo Yao <yaojingguo@gmail.com>

Reviewers: fangmin@apache.org, andor@apache.org

Closes #777 from yaojingguo/fix-typos

zookeeper-docs/src/main/resources/markdown/recipes.md

@@ -227,7 +227,7 @@ Clients wishing to obtain a lock do the following:
 1. The client calls **exists( )** with
   the watch flag set on the path in the lock directory with the next
   lowest sequence number.
-1. if **exists( )** returns false, go
+1. if **exists( )** returns null, go
   to step **2**. Otherwise, wait for a
   notification for the pathname from the previous step before going to
   step **2**.

zookeeper-server/src/main/java/org/apache/zookeeper/ZooKeeper.java

@@ -2428,7 +2428,7 @@ public class ZooKeeper implements AutoCloseable {
      * Return the list of the children of the node of the given path.
      * <p>
      * If the watch is non-null and the call is successful (no exception is thrown),
-     * a watch will be left on the node with the given path. The watch willbe
+     * a watch will be left on the node with the given path. The watch will be
      * triggered by a successful operation that deletes the node of the given
      * path or creates/delete a child under the node.
      * <p>
@@ -2477,7 +2477,7 @@ public class ZooKeeper implements AutoCloseable {
      * Return the list of the children of the node of the given path.
      * <p>
      * If the watch is true and the call is successful (no exception is thrown),
-     * a watch will be left on the node with the given path. The watch willbe
+     * a watch will be left on the node with the given path. The watch will be
      * triggered by a successful operation that deletes the node of the given
      * path or creates/delete a child under the node.
      * <p>
@@ -2542,7 +2542,7 @@ public class ZooKeeper implements AutoCloseable {
      * For the given znode path return the stat and children list.
      * <p>
      * If the watch is non-null and the call is successful (no exception is thrown),
-     * a watch will be left on the node with the given path. The watch willbe
+     * a watch will be left on the node with the given path. The watch will be
      * triggered by a successful operation that deletes the node of the given
      * path or creates/delete a child under the node.
      * <p>
@@ -2598,7 +2598,7 @@ public class ZooKeeper implements AutoCloseable {
      * For the given znode path return the stat and children list.
      * <p>
      * If the watch is true and the call is successful (no exception is thrown),
-     * a watch will be left on the node with the given path. The watch willbe
+     * a watch will be left on the node with the given path. The watch will be
      * triggered by a successful operation that deletes the node of the given
      * path or creates/delete a child under the node.
      * <p>