feat(core): add getR2dbcUrl() method for R2DBC support in PostgreSQLContainer

Author: Ruwais-zaid

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

@@ -67,7 +67,7 @@ public JdbcDatabaseContainer(final DockerImageName dockerImageName) {
     }
 
     /**
-     * @return the name of the actual JDBC driver to use
+     * @return R2DBC driver name (e.g., "postgresql", "mysql", etc.)
      */
     public abstract String getDriverClassName();
 
@@ -77,8 +77,20 @@ public JdbcDatabaseContainer(final DockerImageName dockerImageName) {
     public abstract String getJdbcUrl();
 
     /**
-     * @return the database name
+     * @return an R2DBC-compliant connection URL.
+     * Example: r2dbc:postgresql://user:password@localhost:5432/dbname
      */
+    public String getR2dbcUrl(){
+        String driver = getR2dbcDriverName();
+        String user = getUsername();
+        String pw = getPassword();
+        String host = getHost();
+        Integer port = getFirstMappedPort(getExposedPorts().get(0));
+        String db = getDatabaseName();
+
+        
+    return String.format("r2dbc:%s://%s:%s@%s:%d/%s", driver, user, pw, host, port, db);
+    }
     public String getDatabaseName() {
         throw new UnsupportedOperationException();
     }

modules/postgresql/src/main/java/org/testcontainers/containers/PostgreSQLContainerProvider.java

@@ -31,4 +31,8 @@ public JdbcDatabaseContainer newInstance(String tag) {
     public JdbcDatabaseContainer newInstance(ConnectionUrl connectionUrl) {
         return newInstanceFromConnectionUrl(connectionUrl, USER_PARAM, PASSWORD_PARAM);
     }
+    @Override
+    public String getR2dbcDriverName() {
+        return "postgresql";
+    }
 }

modules/postgresql/src/test/java/org/testcontainers/containers/PostgreSQLR2DBCDatabaseContainerTest.java

@@ -20,7 +20,8 @@ protected ConnectionFactoryOptions getOptions(PostgreSQLContainer<?> container)
         );
         // }
         // spotless:on
-
+        System.out.println("Generated R2DBC URL: " + container.getR2dbcUrl());
+        assertTrue(container.getR2dbcUrl().startsWith("r2dbc:postgresql://"));
         return options;
     }