Java 27 and 26: runnable demos and captured output for every JEP, plus version lanes

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01B38FGKKam5SCGgwgduVAh3

jep-tour/src/broken/Pem26Style.java

@@ -0,0 +1,26 @@
+import java.security.DEREncodable;
+import java.security.PEM;
+import java.security.PEMDecoder;
+import java.security.Provider;
+import java.security.Security;
+
+/**
+ * JDK 26 code for the PEM preview API. It compiles on 26 and fails on 27.
+ * Three things moved between the second and third preview (JEP 524 -> JEP 538):
+ *   1. DEREncodable was renamed BinaryEncodable
+ *   2. PEMDecoder.withFactory(Provider) became withFactoriesOf(Provider)
+ *   3. PEM was a record whose content() returned a String; it is now a class whose content() returns byte[]
+ * Driven by scripts/broken-on-27.sh, which commits the compiler's own messages.
+ */
+public class Pem26Style {
+    public static void main(String[] args) {
+        String text = "-----BEGIN ANKURM DEMO-----\naGVsbG8=\n-----END ANKURM DEMO-----\n";
+        DEREncodable decoded = PEMDecoder.of().decode(text);                    // 1
+        Provider provider = Security.getProviders()[0];
+        PEMDecoder viaProvider = PEMDecoder.of().withFactory(provider);         // 2
+        if (decoded instanceof PEM pem) {
+            String base64Text = pem.content();                                  // 3
+            System.out.println(pem.type() + " / " + base64Text);
+        }
+    }
+}