Add getR2dbcUrl() method to JdbcDatabaseContainer (#8797)

Author: NiMv1

modules/jdbc/src/main/java/org/testcontainers/containers/JdbcDatabaseContainer.java

@@ -76,6 +76,26 @@ public JdbcDatabaseContainer(final DockerImageName dockerImageName) {
      */
     public abstract String getJdbcUrl();
 
+    /**
+     * Returns an R2DBC URL that may be used to connect to the dockerized DB using reactive drivers.
+     * <p>
+     * The default implementation converts the JDBC URL to R2DBC format by replacing
+     * the "jdbc:" prefix with "r2dbc:". Subclasses may override this method if
+     * a different conversion is required.
+     *
+     * @return an R2DBC URL for reactive database connections
+     * @see <a href="https://r2dbc.io/spec/1.0.0.RELEASE/spec/html/">R2DBC Specification</a>
+     */
+    public String getR2dbcUrl() {
+        String jdbcUrl = getJdbcUrl();
+        if (jdbcUrl != null && jdbcUrl.startsWith("jdbc:")) {
+            return "r2dbc:" + jdbcUrl.substring(5);
+        }
+        throw new UnsupportedOperationException(
+            "Cannot convert JDBC URL to R2DBC format. Override getR2dbcUrl() in subclass."
+        );
+    }
+
     /**
      * @return the database name
      */

modules/jdbc/src/test/java/org/testcontainers/containers/JdbcDatabaseContainerTest.java

@@ -7,11 +7,33 @@
 import java.sql.Connection;
 import java.sql.SQLException;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.mockito.Mockito.mock;
 
 class JdbcDatabaseContainerTest {
 
+    @Test
+    void getR2dbcUrlConvertsJdbcUrlToR2dbcFormat() {
+        JdbcDatabaseContainer<?> container = new JdbcDatabaseContainerStubWithUrl(
+            "mysql:latest",
+            "jdbc:mysql://localhost:3306/testdb"
+        );
+
+        String r2dbcUrl = container.getR2dbcUrl();
+
+        assertThat(r2dbcUrl).isEqualTo("r2dbc:mysql://localhost:3306/testdb");
+    }
+
+    @Test
+    void getR2dbcUrlThrowsExceptionWhenJdbcUrlIsNull() {
+        JdbcDatabaseContainer<?> container = new JdbcDatabaseContainerStub("mysql:latest");
+
+        assertThatExceptionOfType(UnsupportedOperationException.class)
+            .isThrownBy(container::getR2dbcUrl)
+            .withMessageContaining("Cannot convert JDBC URL to R2DBC format");
+    }
+
     @Test
     void anExceptionIsThrownIfJdbcIsNotAvailable() {
         JdbcDatabaseContainer<?> jdbcContainer = new JdbcDatabaseContainerStub("mysql:latest")
@@ -69,4 +91,19 @@ protected Logger logger() {
         @Override
         public void setDockerImageName(@NonNull String dockerImageName) {}
     }
+
+    static class JdbcDatabaseContainerStubWithUrl extends JdbcDatabaseContainerStub {
+
+        private final String jdbcUrl;
+
+        public JdbcDatabaseContainerStubWithUrl(@NonNull String dockerImageName, String jdbcUrl) {
+            super(dockerImageName);
+            this.jdbcUrl = jdbcUrl;
+        }
+
+        @Override
+        public String getJdbcUrl() {
+            return jdbcUrl;
+        }
+    }
 }