Change Function interface to BiFunction

Author: sakthivelmanii

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

@@ -24,6 +24,7 @@
 import java.math.BigDecimal;
 import java.util.List;
 import java.util.UUID;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 
 /**
@@ -179,58 +180,55 @@ default float getFloat(String columnName) {
   /**
    * @param columnIndex index of the column
    * @return the value of a column with type T or null if the column contains a null value
-   * <p>Example
-   *
-   * <pre>{@code
+   *     <p>Example
+   *     <pre>{@code
    * Struct row = ...
-   * String name = row.getOrNull(1, row::getString)
+   * String name = row.getOrNull(1, StructReader::getString)
    * }</pre>
    */
-  default <T> T getOrNull(int columnIndex, Function<Integer, T> function) {
-    return isNull(columnIndex) ? null : function.apply(columnIndex);
+  default <T> T getOrNull(int columnIndex, BiFunction<StructReader, Integer, T> function) {
+    return isNull(columnIndex) ? null : function.apply(this, columnIndex);
   }
 
   /**
    * @param columnName index of the column
    * @return the value of a column with type T or null if the column contains a null value
-   * <p>Example
-   *
-   * <pre>{@code
+   *     <p>Example
+   *     <pre>{@code
    * Struct row = ...
-   * String name = row.getOrNull("name", row::getString)
+   * String name = row.getOrNull("name", StructReader::getString)
    * }</pre>
    */
-  default <T> T getOrNull(String columnName, Function<String, T> function) {
-    return isNull(columnName) ? null : function.apply(columnName);
+  default <T> T getOrNull(String columnName, BiFunction<StructReader, String, T> function) {
+    return isNull(columnName) ? null : function.apply(this, columnName);
   }
 
   /**
    * @param columnIndex index of the column
    * @return the value of a column with type T, or the given default if the column value is null
-   * <p>Example
-   *
-   * <pre>{@code
+   *     <p>Example
+   *     <pre>{@code
    * Struct row = ...
-   * String name = row.getOrDefault(1, row::getString, "")
+   * String name = row.getOrDefault(1, StructReader::getString, "")
    * }</pre>
    */
-  default <T> T getOrDefault(int columnIndex, Function<Integer, T> function, T defaultValue) {
-    return isNull(columnIndex) ? defaultValue : function.apply(columnIndex);
+  default <T> T getOrDefault(
+      int columnIndex, BiFunction<StructReader, Integer, T> function, T defaultValue) {
+    return isNull(columnIndex) ? defaultValue : function.apply(this, columnIndex);
   }
 
   /**
    * @param columnName name of the column
    * @return the value of a column with type T, or the given default if the column value is null
-   *
-   * <p>Example
-   *
-   * <pre>{@code
+   *     <p>Example
+   *     <pre>{@code
    * Struct row = ...
-   * String name = row.getOrDefault("name", row::getString, "")
+   * String name = row.getOrDefault("name", StructReader::getString, "")
    * }</pre>
    */
-  default <T> T getOrDefault(String columnName, Function<String, T> function, T defaultValue) {
-    return isNull(columnName) ? defaultValue : function.apply(columnName);
+  default <T> T getOrDefault(
+      String columnName, BiFunction<StructReader, String, T> function, T defaultValue) {
+    return isNull(columnName) ? defaultValue : function.apply(this, columnName);
   }
 
   /**

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

@@ -68,13 +68,13 @@ public void getOrNullTests() {
             .set("f3")
             .to(Value.bool(null))
             .build();
-    String column1 = struct.getOrNull(0, struct::getString);
+    String column1 = struct.getOrNull(0, StructReader::getString);
     assertThat(column1).isEqualTo("x");
 
-    Long column2 = struct.getOrNull(1, struct::getLong);
+    Long column2 = struct.getOrNull(1, StructReader::getLong);
     assertThat(column2).isEqualTo(2);
 
-    String column3 = struct.getOrNull("f3", struct::getString);
+    String column3 = struct.getOrNull("f3", StructReader::getString);
     assertThat(column3).isNull();
   }
 
@@ -89,13 +89,13 @@ public void getOrDefaultTests() {
             .set("f3")
             .to(Value.bool(null))
             .build();
-    String column1 = struct.getOrDefault(0, struct::getString, "");
+    String column1 = struct.getOrDefault(0, StructReader::getString, "");
     assertThat(column1).isEqualTo("x");
 
-    Long column2 = struct.getOrDefault("f2", struct::getLong, -1L);
+    Long column2 = struct.getOrDefault("f2", StructReader::getLong, -1L);
     assertThat(column2).isEqualTo(2);
 
-    String column3 = struct.getOrDefault(2, struct::getString, "");
+    String column3 = struct.getOrDefault(2, StructReader::getString, "");
     assertThat(column3).isEqualTo("");
   }