Fix regression in BeanPropertyRowMapper.underscoreName(String)

Commit 6316a35 introduced a regression for property names starting with
multiple uppercase letters (such as setEMail(...)).

This commit fixes that regression and includes an additional test to
cover this case.

See gh-27929
Closes gh-27941

spring-jdbc/src/main/java/org/springframework/jdbc/core/BeanPropertyRowMapper.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -273,7 +273,8 @@ public class BeanPropertyRowMapper<T> implements RowMapper<T> {
 		}
 
 		StringBuilder result = new StringBuilder();
-		for (int i = 0; i < name.length(); i++) {
+		result.append(Character.toLowerCase(name.charAt(0)));
+		for (int i = 1; i < name.length(); i++) {
 			char c = name.charAt(i);
 			if (Character.isUpperCase(c)) {
 				result.append('_').append(Character.toLowerCase(c));

spring-jdbc/src/test/java/org/springframework/jdbc/core/AbstractRowMapperTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,6 +30,7 @@ import org.springframework.beans.PropertyAccessorFactory;
 import org.springframework.jdbc.core.test.ConcretePerson;
 import org.springframework.jdbc.core.test.ConstructorPerson;
 import org.springframework.jdbc.core.test.DatePerson;
+import org.springframework.jdbc.core.test.EmailPerson;
 import org.springframework.jdbc.core.test.Person;
 import org.springframework.jdbc.core.test.SpacePerson;
 import org.springframework.jdbc.datasource.SingleConnectionDataSource;
@@ -97,6 +98,14 @@ public abstract class AbstractRowMapperTests {
 		assertThat(bw.getPropertyValue("balance")).isEqualTo(new BigDecimal("1234.56"));
 	}
 
+	protected void verifyPerson(EmailPerson person) {
+		assertThat(person.getName()).isEqualTo("Bubba");
+		assertThat(person.getAge()).isEqualTo(22L);
+		assertThat(person.getBirth_date()).usingComparator(Date::compareTo).isEqualTo(new java.util.Date(1221222L));
+		assertThat(person.getBalance()).isEqualTo(new BigDecimal("1234.56"));
+		assertThat(person.getEMail()).isEqualTo("hello@world.info");
+	}
+
 
 	protected enum MockType {ONE, TWO, THREE};
 
@@ -136,19 +145,22 @@ public abstract class AbstractRowMapperTests {
 			given(resultSet.getDate(3)).willReturn(new java.sql.Date(1221222L));
 			given(resultSet.getBigDecimal(4)).willReturn(new BigDecimal("1234.56"));
 			given(resultSet.getObject(4)).willReturn(new BigDecimal("1234.56"));
+			given(resultSet.getString(5)).willReturn("hello@world.info");
 			given(resultSet.wasNull()).willReturn(type == MockType.TWO);
 
-			given(resultSetMetaData.getColumnCount()).willReturn(4);
+			given(resultSetMetaData.getColumnCount()).willReturn(5);
 			given(resultSetMetaData.getColumnLabel(1)).willReturn(
 					type == MockType.THREE ? "Last Name" : "name");
 			given(resultSetMetaData.getColumnLabel(2)).willReturn("age");
 			given(resultSetMetaData.getColumnLabel(3)).willReturn("birth_date");
 			given(resultSetMetaData.getColumnLabel(4)).willReturn("balance");
+			given(resultSetMetaData.getColumnLabel(5)).willReturn("e_mail");
 
 			given(resultSet.findColumn("name")).willReturn(1);
 			given(resultSet.findColumn("age")).willReturn(2);
 			given(resultSet.findColumn("birth_date")).willReturn(3);
 			given(resultSet.findColumn("balance")).willReturn(4);
+			given(resultSet.findColumn("e_mail")).willReturn(5);
 
 			jdbcTemplate = new JdbcTemplate();
 			jdbcTemplate.setDataSource(new SingleConnectionDataSource(connection, false));

spring-jdbc/src/test/java/org/springframework/jdbc/core/BeanPropertyRowMapperTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import org.springframework.beans.TypeMismatchException;
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.jdbc.core.test.ConcretePerson;
 import org.springframework.jdbc.core.test.DatePerson;
+import org.springframework.jdbc.core.test.EmailPerson;
 import org.springframework.jdbc.core.test.ExtendedPerson;
 import org.springframework.jdbc.core.test.Person;
 import org.springframework.jdbc.core.test.SpacePerson;
@@ -134,4 +135,15 @@ public class BeanPropertyRowMapperTests extends AbstractRowMapperTests {
 		mock.verifyClosed();
 	}
 
+	@Test
+	public void testQueryWithUnderscoreAndPersonWithMultipleAdjacentUppercaseLettersInPropertyName() throws Exception {
+		Mock mock = new Mock();
+		List<EmailPerson> result = mock.getJdbcTemplate().query(
+				"select name, age, birth_date, balance, e_mail from people",
+				new BeanPropertyRowMapper<>(EmailPerson.class));
+		assertThat(result.size()).isEqualTo(1);
+		verifyPerson(result.get(0));
+		mock.verifyClosed();
+	}
+
 }

spring-jdbc/src/test/java/org/springframework/jdbc/core/test/EmailPerson.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2002-2022 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.jdbc.core.test;
+
+import java.math.BigDecimal;
+import java.util.Date;
+
+/**
+ * @author Thomas Risberg
+ * @author Marten Deinum
+ */
+public class EmailPerson {
+
+	private String name;
+
+	private long age;
+
+	private Date birth_date;
+
+	private BigDecimal balance;
+
+	private String eMail;
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public long getAge() {
+		return age;
+	}
+
+	public void setAge(long age) {
+		this.age = age;
+	}
+
+	public Date getBirth_date() {
+		return birth_date;
+	}
+
+	public void setBirth_date(Date birth_date) {
+		this.birth_date = birth_date;
+	}
+
+	public BigDecimal getBalance() {
+		return balance;
+	}
+
+	public void setBalance(BigDecimal balance) {
+		this.balance = balance;
+	}
+
+	public void setEMail(String email) {
+		this.eMail=email;
+	}
+
+	public String getEMail() {
+		return this.eMail;
+	}
+
+}