HBASE-19031 Align exist method in Table and AsyncTable interfaces

Deprecate Table::existsAll method and add Table::exists.
RemoteHTable already had a deprecated exists method, remove that
and implement the new exists from Table interface.

Signed-off-by: Chia-Ping Tsai <chia7712@gmail.com>

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HTable.java

@@ -945,11 +945,8 @@ public class HTable implements Table {
     return r.getExists();
   }
 
-  /**
-   * {@inheritDoc}
-   */
   @Override
-  public boolean[] existsAll(final List<Get> gets) throws IOException {
+  public boolean[] exists(List<Get> gets) throws IOException {
     if (gets.isEmpty()) return new boolean[]{};
     if (gets.size() == 1) return new boolean[]{exists(gets.get(0))};
 

hbase-client/src/main/java/org/apache/hadoop/hbase/client/Table.java

@@ -110,7 +110,25 @@ public interface Table extends Closeable {
    * @return Array of boolean.  True if the specified Get matches one or more keys, false if not.
    * @throws IOException e
    */
-  boolean[] existsAll(List<Get> gets) throws IOException;
+  boolean[] exists(List<Get> gets) throws IOException;
+
+  /**
+   * Test for the existence of columns in the table, as specified by the Gets.
+   * This will return an array of booleans. Each value will be true if the related Get matches
+   * one or more keys, false if not.
+   * This is a server-side call so it prevents any data from being transferred to
+   * the client.
+   *
+   * @param gets the Gets
+   * @return Array of boolean.  True if the specified Get matches one or more keys, false if not.
+   * @throws IOException e
+   * @deprecated since 2.0 version and will be removed in 3.0 version.
+   *             use {@link #exists(List)}
+   */
+  @Deprecated
+  default boolean[] existsAll(List<Get> gets) throws IOException {
+    return exists(gets);
+  }
 
   /**
    * Method that does a batch call on Deletes, Gets, Puts, Increments, Appends, RowMutations.

hbase-rest/src/main/java/org/apache/hadoop/hbase/rest/client/RemoteHTable.java

@@ -367,12 +367,8 @@ public class RemoteHTable implements Table {
     return (result != null && !(result.isEmpty()));
   }
 
-  /**
-   * exists(List) is really a list of get() calls. Just use get().
-   * @param gets list of Get to test for the existence
-   */
   @Override
-  public boolean[] existsAll(List<Get> gets) throws IOException {
+  public boolean[] exists(List<Get> gets) throws IOException {
     LOG.warn("exists(List<Get>) is really list of get() calls, just use get()");
     boolean[] results = new boolean[gets.size()];
     for (int i = 0; i < results.length; i++) {
@@ -381,16 +377,6 @@ public class RemoteHTable implements Table {
     return results;
   }
 
-  @Deprecated
-  public Boolean[] exists(List<Get> gets) throws IOException {
-    boolean[] results = existsAll(gets);
-    Boolean[] objectResults = new Boolean[results.length];
-    for (int i = 0; i < results.length; ++i) {
-      objectResults[i] = results[i];
-    }
-    return objectResults;
-  }
-
   @Override
   public void put(Put put) throws IOException {
     CellSetModel model = buildModelFromPut(put);

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/RegionAsTable.java

@@ -100,7 +100,7 @@ public class RegionAsTable implements Table {
   }
 
   @Override
-  public boolean[] existsAll(List<Get> gets) throws IOException {
+  public boolean[] exists(List<Get> gets) throws IOException {
     boolean [] results = new boolean[gets.size()];
     int index = 0;
     for (Get get: gets) {