GH-3282: Fix JdbcMetadataStore for DuplicateKeyEx (#3285)

* GH-3282: Fix JdbcMetadataStore for DuplicateKeyEx

Fixes: https://github.com/spring-projects/spring-integration/issues/3282

The `INSERT INTO ... SELECT ... FROM ... HAVING` may fail with
`DuplicateKeyException` in between transactions.
* Catch `DuplicateKeyException` from in the `tryToPutIfAbsent()`
and return `0` as a fact of not inserted to let other logic to work
as expected.

There is no test coverage for this since it is almost impossible to
reproduce such a race condition on DB

**Cherry-pick to 5.3.x & 5.2.x**

* * Remove misleading message in the comment sentence

spring-integration-jdbc/src/test/java/org/springframework/integration/jdbc/metadata/JdbcMetadataStoreTests.java

@@ -20,14 +20,12 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 import javax.sql.DataSource;
 
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.annotation.DirtiesContext;
-import org.springframework.test.context.ContextConfiguration;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 import org.springframework.transaction.annotation.Transactional;
 
 /**
@@ -36,8 +34,7 @@ import org.springframework.transaction.annotation.Transactional;
  *
  * @since 5.0
  */
-@ContextConfiguration
-@RunWith(SpringJUnit4ClassRunner.class)
+@SpringJUnitConfig
 @DirtiesContext // close at the end after class
 @Transactional
 public class JdbcMetadataStoreTests {
@@ -48,7 +45,7 @@ public class JdbcMetadataStoreTests {
 
 	private JdbcMetadataStore metadataStore;
 
-	@Before
+	@BeforeEach
 	public void init() {
 		metadataStore = new JdbcMetadataStore(dataSource);
 		metadataStore.afterPropertiesSet();