refactor: use package name following Java guidelines

src/main/java/dev/dnpm/services/DefaultFormService.java

@@ -0,0 +1,37 @@
+package dev.dnpm.services;
+
+import dev.dnpm.exceptions.FormException;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+import javax.sql.DataSource;
+import java.util.List;
+
+/**
+ * Standardimplementierung zum Ermitteln von Unter- und Hauptformularen
+ *
+ * @since 0.0.2
+ */
+public class DefaultFormService implements FormService {
+
+    private final JdbcTemplate jdbcTemplate;
+
+    public DefaultFormService(final DataSource dataSource) {
+        this.jdbcTemplate = new JdbcTemplate(dataSource);
+    }
+
+    @Override
+    public int getMainFormProcedureId(int procedureId) throws FormException {
+        var sql = "SELECT hauptprozedur_id FROM prozedur WHERE id = ?";
+        try {
+            return jdbcTemplate.queryForObject(sql, (resultSet, i) -> resultSet.getInt("hauptprozedur_id"), procedureId);
+        } catch (Exception e) {
+            throw new FormException(String.format("No main form found for subform with ID '%d'", procedureId));
+        }
+    }
+
+    @Override
+    public List<Integer> getSubFormProcedureIds(int procedureId) {
+        var sql = "SELECT id FROM prozedur WHERE hauptprozedur_id = ?";
+        return jdbcTemplate.queryForList(sql, Integer.class, procedureId);
+    }
+}