Add a module-info file.

pgjdbc/build.gradle.kts

@@ -173,6 +173,8 @@ val generateGettextSources by tasks.registering {
 
 tasks.compileJava {
     options.release = 11
+    options.compilerArgs.add("--add-reads")
+    options.compilerArgs.add("org.postgresql.jdbc=ALL-UNNAMED")
     if (enableGettext) {
         dependsOn(generateGettextSources)
     } else {

pgjdbc/src/main/java/module-info.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023, PostgreSQL Global Development Group
+ * See the LICENSE file in the project root for more information.
+ */
+
+/**
+ * JDNC driver for PostgreSQL.
+ */
+module org.postgresql.jdbc {
+    requires transitive java.sql;
+    requires transitive java.desktop;               // Use for java.awt.Point
+    requires transitive java.naming;
+
+    requires java.management;
+    requires java.security.jgss;                    // TODO: make transitive if org.postgresql.gss is exported
+    requires org.checkerframework.checker.qual;
+
+    exports org.postgresql;
+    exports org.postgresql.ds;
+    exports org.postgresql.core;
+    exports org.postgresql.util;
+    // TODO: what else to export?
+
+    provides java.sql.Driver with org.postgresql.Driver;
+}