8373097: Save command should create missing parent directories

Reviewed-by: jlahoda

Author: sormuras

src/jdk.jshell/share/classes/jdk/internal/jshell/tool/JShellTool.java

@@ -3362,7 +3362,19 @@ private boolean cmdSave(String rawargs) {
             // error occurred, already reported
             return false;
         }
-        try (BufferedWriter writer = Files.newBufferedWriter(toPathResolvingUserHome(filename),
+        // Create missing parent directories before writing to target file
+        Path target;
+        try {
+            target = toPathResolvingUserHome(filename);
+            Path parent = target.getParent();
+            if (parent != null) {
+                Files.createDirectories(parent);
+            }
+        } catch (Exception e) {
+            errormsg("jshell.err.file.exception", "/save", filename, e);
+            return false;
+        }
+        try (BufferedWriter writer = Files.newBufferedWriter(target,
                 Charset.defaultCharset(),
                 CREATE, TRUNCATE_EXISTING, WRITE)) {
             if (at.hasOption("-history")) {

test/langtools/jdk/jshell/ToolBasicTest.java

@@ -585,6 +585,7 @@ public void testSave() throws IOException {
         Compiler compiler = new Compiler();
         Path path = compiler.getPath("testSave.repl");
         {
+            Path pathWithDirectories = compiler.getPath("what/ever/testSave.repl");
             List<String> list = Arrays.asList(
                     "int a;",
                     "class A { public String toString() { return \"A\"; } }"
@@ -593,9 +594,11 @@ public void testSave() throws IOException {
                     (a) -> assertVariable(a, "int", "a"),
                     (a) -> assertCommand(a, "()", null, null, null, "", ""),
                     (a) -> assertClass(a, "class A { public String toString() { return \"A\"; } }", "class", "A"),
-                    (a) -> assertCommand(a, "/save " + path.toString(), "")
+                    (a) -> assertCommand(a, "/save " + path.toString(), ""),
+                    (a) -> assertCommand(a, "/save " + pathWithDirectories.toString(), "")
             );
             assertEquals(list, Files.readAllLines(path));
+            assertEquals(list, Files.readAllLines(pathWithDirectories));
         }
         {
             List<String> output = new ArrayList<>();