Addressed comments

Author: sakthivelmanii

google-cloud-spanner/clirr-ignored-differences.xml

@@ -1008,4 +1008,24 @@
     <className>com/google/cloud/spanner/TransactionManager</className>
     <method>com.google.cloud.spanner.TransactionContext begin(com.google.cloud.spanner.AbortedException)</method>
   </difference>
+  <difference>
+    <differenceType>7012</differenceType>
+    <className>com/google/cloud/spanner/StructReader</className>
+    <method>java.lang.Object getOrNull(int, java.util.function.Function)</method>
+  </difference>
+  <difference>
+    <differenceType>7012</differenceType>
+    <className>com/google/cloud/spanner/StructReader</className>
+    <method>java.lang.Object getOrNull(java.lang.String, java.util.function.Function)</method>
+  </difference>
+  <difference>
+    <differenceType>7012</differenceType>
+    <className>com/google/cloud/spanner/StructReader</className>
+    <method>java.lang.Object getOrDefault(int, java.util.function.Function, java.lang.Object)</method>
+  </difference>
+  <difference>
+    <differenceType>7012</differenceType>
+    <className>com/google/cloud/spanner/StructReader</className>
+    <method>java.lang.Object getOrDefault(java.lang.String, java.util.function.Function, java.lang.Object)</method>
+  </difference>
 </differences>

google-cloud-spanner/src/main/java/com/google/cloud/spanner/StructReader.java

@@ -178,31 +178,56 @@ default float getFloat(String columnName) {
 
   /**
    * @param columnIndex index of the column
-   * @return the value of a column with type T. return value(T) can be null.
+   * @return the value of a column with type T or null if the column contains a null value
+   * <p>Example
+   *
+   * <pre>{@code
+   * Struct row = ...
+   * String name = row.getOrNull(1, row::getString)
+   * }</pre>
    */
   default <T> T getOrNull(int columnIndex, Function<Integer, T> function) {
     return isNull(columnIndex) ? null : function.apply(columnIndex);
   }
 
   /**
    * @param columnName index of the column
-   * @return the value of a column with type T. return value(T) can be null.
+   * @return the value of a column with type T or null if the column contains a null value
+   * <p>Example
+   *
+   * <pre>{@code
+   * Struct row = ...
+   * String name = row.getOrNull("name", row::getString)
+   * }</pre>
    */
   default <T> T getOrNull(String columnName, Function<String, T> function) {
     return isNull(columnName) ? null : function.apply(columnName);
   }
 
   /**
    * @param columnIndex index of the column
-   * @return the value of a column with type T. if column value is null, returns default value.
+   * @return the value of a column with type T, or the given default if the column value is null
+   * <p>Example
+   *
+   * <pre>{@code
+   * Struct row = ...
+   * String name = row.getOrDefault(1, row::getString, "")
+   * }</pre>
    */
   default <T> T getOrDefault(int columnIndex, Function<Integer, T> function, T defaultValue) {
     return isNull(columnIndex) ? defaultValue : function.apply(columnIndex);
   }
 
   /**
    * @param columnName name of the column
-   * @return the value of a column with type T. if column value is null, returns default value.
+   * @return the value of a column with type T, or the given default if the column value is null
+   *
+   * <p>Example
+   *
+   * <pre>{@code
+   * Struct row = ...
+   * String name = row.getOrDefault("name", row::getString, "")
+   * }</pre>
    */
   default <T> T getOrDefault(String columnName, Function<String, T> function, T defaultValue) {
     return isNull(columnName) ? defaultValue : function.apply(columnName);