Refactoring: reorg Maven modules for reusability #84

* refactoring extension loading

Author: andrus

jjava-distro/src/main/java/org/dflib/jjava/distro/NotebookInitializer.java

@@ -0,0 +1,34 @@
+package org.dflib.jjava.distro;
+
+import org.dflib.jjava.jupyter.Extension;
+import org.dflib.jjava.jupyter.kernel.BaseKernel;
+import org.dflib.jjava.jupyter.kernel.BaseNotebookStatics;
+import org.dflib.jjava.kernel.JavaNotebookStatics;
+
+/**
+ * An automatically-loaded extension that adds common imports to the notebook. This includes static method imports
+ * from {@link BaseNotebookStatics} and {@link JavaNotebookStatics}.
+ */
+public class NotebookInitializer implements Extension {
+
+    private static final String BASE_STATICS_CLASS = BaseNotebookStatics.class.getName();
+    private static final String JAVA_STATICS_CLASS = JavaNotebookStatics.class.getName();
+
+    private static final String STARTUP_SCRIPT = "import java.util.*;\n" +
+            "import java.io.*;\n" +
+            "import java.math.*;\n" +
+            "import java.net.*;\n" +
+            "import java.time.*;\n" +
+
+            "import java.util.concurrent.*;\n" +
+            "import java.util.prefs.*;\n" +
+            "import java.util.regex.*;\n" +
+
+            "import static " + BASE_STATICS_CLASS + ".*;\n" +
+            "import static " + JAVA_STATICS_CLASS + ".*;";
+
+    @Override
+    public void install(BaseKernel kernel) {
+        kernel.eval(STARTUP_SCRIPT);
+    }
+}

jjava-distro/src/main/resources/META-INF/services/org.dflib.jjava.jupyter.Extension

@@ -0,0 +1 @@
+org.dflib.jjava.distro.NotebookInitializer

…java/jupyter/kernel/NotebookStatics.java …/jupyter/kernel/BaseNotebookStatics.javajjava-jupyter/src/main/java/org/dflib/jjava/jupyter/kernel/NotebookStatics.java renamed to jjava-jupyter/src/main/java/org/dflib/jjava/jupyter/kernel/BaseNotebookStatics.java jjava-jupyter/src/main/java/org/dflib/jjava/jupyter/kernel/NotebookStatics.java renamed to jjava-jupyter/src/main/java/org/dflib/jjava/jupyter/kernel/BaseNotebookStatics.java

@@ -9,39 +9,26 @@
 import java.util.UUID;
 
 /**
- * A collection of methods exposed in every notebook via static imports. For the methods to work, an instance of
- * NotebookStatics must be loaded as a kernel extension, as this is when the kernel becomes known to the class.
+ * An automatically-loaded extension that exposes a collection of static methods for notebook code to interact with the
+ * kernel.
  */
-public class NotebookStatics implements Extension {
-
-    private static final String STARTUP_SCRIPT = "import java.util.*;\n" +
-            "import java.io.*;\n" +
-            "import java.math.*;\n" +
-            "import java.net.*;\n" +
-            "import java.time.*;\n" +
-
-            "import java.util.concurrent.*;\n" +
-            "import java.util.prefs.*;\n" +
-            "import java.util.regex.*;\n" +
-
-            "import static org.dflib.jjava.jupyter.kernel.NotebookStatics.*;";
+public class BaseNotebookStatics implements Extension {
 
     private static BaseKernel kernel;
 
     @Override
     public void install(BaseKernel kernel) {
 
-        if (NotebookStatics.kernel != null) {
-            throw new IllegalStateException("Already initialized with another kernel: " + NotebookStatics.kernel.getBanner());
+        if (BaseNotebookStatics.kernel != null) {
+            throw new IllegalStateException("Already initialized with another kernel: " + BaseNotebookStatics.kernel.getBanner());
         }
 
-        kernel.eval(STARTUP_SCRIPT);
-        NotebookStatics.kernel = kernel;
+        BaseNotebookStatics.kernel = kernel;
     }
 
     private static BaseKernel nonNullKernel() {
         return Objects.requireNonNull(
-                NotebookStatics.kernel,
+                BaseNotebookStatics.kernel,
                 "No kernel running. Likely called outside of the notebook lifecycle");
     }
 

jjava-jupyter/src/main/java/org/dflib/jjava/jupyter/kernel/magic/MagicTranspiler.java

@@ -1,5 +1,7 @@
 package org.dflib.jjava.jupyter.kernel.magic;
 
+import org.dflib.jjava.jupyter.kernel.BaseNotebookStatics;
+
 import java.util.Base64;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -12,9 +14,13 @@ public class MagicTranspiler {
 
     private static final Pattern UNESCAPED_QUOTE = Pattern.compile("(?<!\\\\)\"");
 
+    // generated code templates
+    private static final String CELL_CALL_TEMPLATE = BaseNotebookStatics.class.getName() + ".cellMagic(%s,java.util.List.of(%s),%s);{};";
+    private static final String LINE_CALL_TEMPLATE = BaseNotebookStatics.class.getName() + ".lineMagic(%s,java.util.List.of(%s));{};";
+    private static final String DECODE_TEMPLATE = "new String(java.util.Base64.getDecoder().decode(\"%s\"))";
+
     public String transpileCell(ParsedCellMagic magic) {
-        return String.format(
-                "org.dflib.jjava.jupyter.kernel.NotebookStatics.cellMagic(%s,java.util.List.of(%s),%s);{};",
+        return String.format(CELL_CALL_TEMPLATE,
                 argWithEscapingToJava(magic.magicCall.name),
                 magic.magicCall.args.stream()
                         .map(this::argWithEscapingToJava)
@@ -35,8 +41,7 @@ public String transpileLine(ParsedLineMagic magic) {
             return magic.raw;
         }
 
-        return String.format(
-                "org.dflib.jjava.jupyter.kernel.NotebookStatics.lineMagic(%s,java.util.List.of(%s));{};",
+        return String.format(LINE_CALL_TEMPLATE,
                 argWithEscapingToJava(magic.magicCall.name),
                 magic.magicCall.args.stream()
                         .map(this::argWithEscapingToJava)
@@ -47,6 +52,6 @@ public String transpileLine(ParsedLineMagic magic) {
     // Poor man's string escape
     private String argWithEscapingToJava(String arg) {
         String encoded = Base64.getEncoder().encodeToString(arg.getBytes());
-        return String.format("new String(java.util.Base64.getDecoder().decode(\"%s\"))", encoded);
+        return String.format(DECODE_TEMPLATE, encoded);
     }
 }

jjava-jupyter/src/main/resources/META-INF/services/org.dflib.jjava.jupyter.Extension

@@ -1 +1 @@
-org.dflib.jjava.jupyter.kernel.NotebookStatics
+org.dflib.jjava.jupyter.kernel.BaseNotebookStatics

jjava-kernel/src/main/java/org/dflib/jjava/kernel/JavaNotebookStatics.java

@@ -6,13 +6,11 @@
 import java.util.Objects;
 
 /**
- * A collection of methods exposed in every notebook via static imports. For the methods to work, an instance of
- * JavaNotebookStatics must be loaded as a kernel extension, as this is when the kernel becomes known to the class.
+ * An automatically-loaded extension that exposes a collection of static methods for notebook code to interact with the
+ * kernel.
  */
 public class JavaNotebookStatics implements Extension {
 
-    private static final String STARTUP_SCRIPT = "import static org.dflib.jjava.kernel.JavaNotebookStatics.*;";
-
     private static JavaKernel kernel;
 
     @Override
@@ -23,7 +21,6 @@ public void install(BaseKernel kernel) {
         }
 
         if (kernel instanceof JavaKernel) {
-            kernel.eval(STARTUP_SCRIPT);
             JavaNotebookStatics.kernel = (JavaKernel) kernel;
         } else {
             // TODO: should we have some kind of abstract logger?