Polish "Fix deriving DataSources from custom type"

See gh-27453

Author: wilkinsona

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/jdbc/DataSourceBuilder.java

@@ -281,22 +281,17 @@ public String toString() {
 		}
 
 		Method findSetter(Class<?> type) {
-			return extracted("set", type, true);
+			return extracted("set", type, String.class);
 		}
 
 		Method findGetter(Class<?> type) {
-			return extracted("get", type, false);
+			return extracted("get", type);
 		}
 
-		private Method extracted(String prefix, Class<?> type, boolean hasParameter) {
+		private Method extracted(String prefix, Class<?> type, Class<?>... paramTypes) {
 			for (String candidate : this.names) {
-				Method method;
-				if (hasParameter) {
-					method = ReflectionUtils.findMethod(type, prefix + StringUtils.capitalize(candidate), String.class);
-				}
-				else {
-					method = ReflectionUtils.findMethod(type, prefix + StringUtils.capitalize(candidate));
-				}
+				Method method = ReflectionUtils.findMethod(type, prefix + StringUtils.capitalize(candidate),
+						paramTypes);
 				if (method != null) {
 					return method;
 				}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/jdbc/DataSourceBuilderTests.java

@@ -331,8 +331,23 @@ void buildWhenDerivedFromExistingDatabaseWithTypeChange() {
 		assertThat(built.getUrl()).isEqualTo("jdbc:postgresql://localhost:5432/postgres");
 	}
 
-	@Test // gh -27295
-	void buildWhenDerivedFromCustomTypeSpecifiedReturnsDataSource() {
+	@Test // gh-27295
+	void buildWhenDerivedFromCustomType() {
+		CustomDataSource dataSource = new CustomDataSource();
+		dataSource.setUsername("test");
+		dataSource.setPassword("secret");
+		dataSource.setUrl("jdbc:postgresql://localhost:5432/postgres");
+		DataSourceBuilder<?> builder = DataSourceBuilder.derivedFrom(dataSource).username("alice")
+				.password("confidential");
+		CustomDataSource testSource = (CustomDataSource) builder.build();
+		assertThat(testSource).isNotSameAs(dataSource);
+		assertThat(testSource.getUsername()).isEqualTo("alice");
+		assertThat(testSource.getUrl()).isEqualTo("jdbc:postgresql://localhost:5432/postgres");
+		assertThat(testSource.getPassword()).isEqualTo("confidential");
+	}
+
+	@Test // gh-27295
+	void buildWhenDerivedFromCustomTypeWithTypeChange() {
 		CustomDataSource dataSource = new CustomDataSource();
 		dataSource.setUsername("test");
 		dataSource.setPassword("secret");