Fix snippets

Author: yihanzhen

google-cloud-examples/src/main/java/com/google/cloud/examples/spanner/snippets/DatabaseAdminClientSnippets.java

@@ -34,6 +34,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.concurrent.ExecutionException;
 
 /**
  * This class contains snippets for {@link DatabaseAdminClient} interface.
@@ -71,14 +72,13 @@ public Database createDatabase(String instanceId, String databaseId) {
                     + "  AlbumTitle   STRING(MAX)\n"
                     + ") PRIMARY KEY (SingerId, AlbumId),\n"
                     + "  INTERLEAVE IN PARENT Singers ON DELETE CASCADE"));
-    Database db;
     try {
-      db = op.get();
-    } catch (Exception e) {
-      throw SpannerExceptionFactory.newSpannerException(e);
+      return op.get();
+      // [END createDatabase]
+    } catch (ExecutionException | InterruptedException e) {
+      // DO error handing
     }
-    // [END createDatabase]
-    return db;
+    return null;
   }
 
   /**
@@ -107,8 +107,8 @@ public void updateDatabaseDdl(String instanceId, String databaseId) {
         databaseId, 
         Arrays.asList("ALTER TABLE Albums ADD COLUMN MarketingBudget INT64"), 
         null).get();
-    } catch (Exception e) {
-      throw SpannerExceptionFactory.newSpannerException(e);
+    } catch (ExecutionException | InterruptedException e) {
+      // DO error handling
     }
     // [END updateDatabaseDdl]
   }

google-cloud-spanner/src/test/java/com/google/cloud/spanner/DatabaseAdminClientImplTest.java

@@ -86,7 +86,7 @@ public void getDatabase() {
     assertThat(db.getState()).isEqualTo(DatabaseInfo.State.READY);
   }
 
-  @Test(timeout = 1000)
+  @Test
   public void createDatabase() throws Exception {
     OperationFuture<Database, CreateDatabaseMetadata> rawOperationFuture =
         OperationFutureUtil.immediateOperationFuture(
@@ -117,6 +117,7 @@ public void updateDatabaseDdl() throws Exception {
 
   @Ignore("More work needs to be done")
   @Test
+  // TODO(hzyi)
   // Changing the surface to OperationFuture breaks updateDatabaseDdl in the case
   // that there is already a longrunning operation running. Disabling this test for 
   // this PR and I will fix this in the next PR.