jep511: add the star-import clash demo, java.base export count and a java.time jshell check

TwoStarImports.java, the java.base export count in output/04, the extra LocalDate line in src/imports.jsh and regenerated transcripts. Additive commit.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01TF9JWFvJSNm6HVzswzZU5a

jep511/broken/TwoStarImports.java

@@ -0,0 +1,9 @@
+import java.util.*;
+import java.sql.*;
+
+public class TwoStarImports {
+    public static void main(String[] args) {
+        Date d = new Date(0L);      // the same clash, with the old on-demand imports
+        System.out.println(d);
+    }
+}

jep511/output/02-ambiguity.txt

@@ -34,6 +34,28 @@ broken/AmbiguousList.java:6: error: reference to List is ambiguous
   both class java.awt.List in java.awt and interface java.util.List in java.util match
 1 error
 
+$ javac broken/TwoStarImports.java     (25.0.4.1+1-LTS)
+broken/TwoStarImports.java:6: error: reference to Date is ambiguous
+        Date d = new Date(0L);      // the same clash, with the old on-demand imports
+        ^
+  both class java.sql.Date in java.sql and class java.util.Date in java.util match
+broken/TwoStarImports.java:6: error: reference to Date is ambiguous
+        Date d = new Date(0L);      // the same clash, with the old on-demand imports
+                     ^
+  both class java.sql.Date in java.sql and class java.util.Date in java.util match
+2 errors
+
+$ javac broken/TwoStarImports.java     (27+35)
+broken/TwoStarImports.java:6: error: reference to Date is ambiguous
+        Date d = new Date(0L);      // the same clash, with the old on-demand imports
+        ^
+  both class java.sql.Date in java.sql and class java.util.Date in java.util match
+broken/TwoStarImports.java:6: error: reference to Date is ambiguous
+        Date d = new Date(0L);      // the same clash, with the old on-demand imports
+                     ^
+  both class java.sql.Date in java.sql and class java.util.Date in java.util match
+2 errors
+
 $ javac src/FixedDate.java && java FixedDate     (25.0.4.1+1-LTS)
 java.util.Date
 java.sql.Date

jep511/output/04-what-a-module-import-brings-in.txt

@@ -1,11 +1,14 @@
+$ java --describe-module java.base | grep -c '^exports'     (25.0.4.1+1-LTS)
+58
+
 $ java --describe-module java.sql     (25.0.4.1+1-LTS)
 [email protected]
 exports java.sql
 exports javax.sql
-requires java.xml transitive
-requires java.logging transitive
 requires java.transaction.xa transitive
 requires java.base mandated
+requires java.xml transitive
+requires java.logging transitive
 uses java.sql.Driver
 
 $ java --describe-module java.se | grep -c 'requires'     (25.0.4.1+1-LTS)

jep511/output/09-jshell.txt

@@ -10,12 +10,19 @@ $ jshell --feedback concise src/imports.jsh     (21.0.10+7-Ubuntu-124.04)
   import java.util.regex.*
   import java.util.stream.*
 [2, 4]
+Error:
+cannot find symbol
+  symbol:   variable LocalDate
+System.out.println(LocalDate.of(2026, 9, 15))
+                   ^-------^
 
 $ jshell --feedback concise src/imports.jsh     (25.0.4.1+1-LTS)
   import java.base
 [2, 4]
+2026-09-15
 
 $ jshell --feedback concise src/imports.jsh     (27+35)
   import java.base
 [2, 4]
+2026-09-15
 

jep511/run.sh

@@ -23,7 +23,7 @@ both() { local fn="$1"; shift; "$fn" "$JDK25" "$@"; echo; "$fn" "$JDK27" "$@"; }
 { both cr src/OldWay.java OldWay; echo; both cr src/NewWay.java NewWay; } > "$OUT/01-old-vs-new.txt"
 
 # 02 - ambiguity: two modules export a class with the same simple name
-{ both co broken/AmbiguousDate.java; echo; both co broken/AmbiguousList.java; echo; both cr src/FixedDate.java FixedDate; } > "$OUT/02-ambiguity.txt"
+{ both co broken/AmbiguousDate.java; echo; both co broken/AmbiguousList.java; echo; both co broken/TwoStarImports.java; echo; both cr src/FixedDate.java FixedDate; } > "$OUT/02-ambiguity.txt"
 
 # 03 - precedence: who wins when several imports offer the same simple name
 { both cr src/StarImportWins.java StarImportWins; echo; both cr src/StarImportWinsSql.java StarImportWinsSql; echo
@@ -31,7 +31,8 @@ both() { local fn="$1"; shift; "$fn" "$JDK25" "$@"; echo; "$fn" "$JDK27" "$@"; }
   both cr src/DuplicateImports.java DuplicateImports; } > "$OUT/03-precedence.txt"
 
 # 04 - what one module import actually brings in
-{ echo "\$ java --describe-module java.sql     ($(t "$JDK25"))"; "$JDK25/bin/java" --describe-module java.sql; echo
+{ echo "\$ java --describe-module java.base | grep -c '^exports'     ($(t "$JDK25"))"; "$JDK25/bin/java" --describe-module java.base | grep -c '^exports'; echo
+  echo "\$ java --describe-module java.sql     ($(t "$JDK25"))"; "$JDK25/bin/java" --describe-module java.sql; echo
   echo "\$ java --describe-module java.se | grep -c 'requires'     ($(t "$JDK25"))"; "$JDK25/bin/java" --describe-module java.se | grep -c requires; echo
   echo "\$ java --describe-module java.se | grep -c exports     ($(t "$JDK25"))"; "$JDK25/bin/java" --describe-module java.se | grep -c exports; echo
   both cr src/Transitive.java Transitive; echo; both co broken/SqlDoesNotGiveBase.java; echo

jep511/src/imports.jsh

@@ -1,3 +1,4 @@
 /imports
 System.out.println(List.of(1, 2).stream().map(x -> x * 2).collect(Collectors.toList()))
+System.out.println(LocalDate.of(2026, 9, 15))
 /exit