diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index 736e664665..5d67ba6229 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -1,4 +1,4 @@
-*syntax.txt*	For Vim version 9.1.  Last change: 2024 Aug 22
+*syntax.txt*	For Vim version 9.1.  Last change: 2024 Aug 26
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2164,6 +2164,22 @@ This will make the syntax synchronization start 50 lines before the first
 displayed line.  The default value is 10.  The disadvantage of using a larger
 number is that redrawing can become slow.
 
+Significant changes to the Java platform are gradually introduced in the form
+of JDK Enhancement Proposals (JEPs) that can be implemented for a release and
+offered as its preview features.  It may take several JEPs and a few release
+cycles for such a feature to become either integrated into the platform or
+withdrawn from this effort.  To cater for early adopters, there is optional
+support in Vim for syntax related preview features that are implemented.  You
+can request it by specifying a list of preview feature numbers as follows: >
+	:let g:java_syntax_previews = [430]
+
+The supported JEP numbers are to be drawn from this table:
+	`430`: String Templates [JDK 21]
+
+Note that as soon as the particular preview feature will have been integrated
+into the Java platform, its entry will be removed from the table and related
+optionality will be discontinued.
+
 
 JSON			*json.vim* *ft-json-syntax* *g:vim_json_conceal*
 					       *g:vim_json_warnings*
diff --git a/runtime/syntax/java.vim b/runtime/syntax/java.vim
index 51ef8395b9..8aa053d522 100644
--- a/runtime/syntax/java.vim
+++ b/runtime/syntax/java.vim
@@ -3,7 +3,7 @@
 " Maintainer:		Aliaksei Budavei <0x000c70 AT gmail DOT com>
 " Former Maintainer:	Claudio Fleiner <claudio@fleiner.com>
 " Repository:		https://github.com/zzzyxwvut/java-vim.git
-" Last Change:		2024 Aug 22
+" Last Change:		2024 Aug 26
 
 " Please check :help java.vim for comments on some of the options available.
 
@@ -30,6 +30,10 @@ function! s:ff.RightConstant(x, y) abort
   return a:y
 endfunction
 
+function! s:ff.IsRequestedPreviewFeature(n) abort
+  return exists("g:java_syntax_previews") && index(g:java_syntax_previews, a:n) + 1
+endfunction
+
 if !exists("*s:ReportOnce")
   function s:ReportOnce(message) abort
     echomsg 'syntax/java.vim: ' . a:message
@@ -367,9 +371,14 @@ syn match   javaSpecialChar	contained "\\\%(u\x\x\x\x\|[0-3]\o\o\|\o\o\=\|[bstnf
 syn region  javaString		start=+"+ end=+"+ end=+$+ contains=javaSpecialChar,javaSpecialError,@Spell
 syn region  javaString		start=+"""[ \t\x0c\r]*$+hs=e+1 end=+"""+he=s-1 contains=javaSpecialChar,javaSpecialError,javaTextBlockError,@Spell
 syn match   javaTextBlockError	+"""\s*"""+
-syn region  javaStrTemplEmbExp	contained matchgroup=javaStrTempl start="\\{" end="}" contains=TOP
-exec 'syn region javaStrTempl start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="+ end=+"+ contains=javaStrTemplEmbExp,javaSpecialChar,javaSpecialError,@Spell'
-exec 'syn region javaStrTempl start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="""[ \t\x0c\r]*$+hs=e+1 end=+"""+he=s-1 contains=javaStrTemplEmbExp,javaSpecialChar,javaSpecialError,javaTextBlockError,@Spell'
+
+if s:ff.IsRequestedPreviewFeature(430)
+  syn region javaStrTemplEmbExp	contained matchgroup=javaStrTempl start="\\{" end="}" contains=TOP
+  exec 'syn region javaStrTempl start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="+ end=+"+ contains=javaStrTemplEmbExp,javaSpecialChar,javaSpecialError,@Spell'
+  exec 'syn region javaStrTempl start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="""[ \t\x0c\r]*$+hs=e+1 end=+"""+he=s-1 contains=javaStrTemplEmbExp,javaSpecialChar,javaSpecialError,javaTextBlockError,@Spell'
+  hi def link javaStrTempl	Macro
+endif
+
 syn match   javaCharacter	"'[^']*'" contains=javaSpecialChar,javaSpecialCharError
 syn match   javaCharacter	"'\\''" contains=javaSpecialChar
 syn match   javaCharacter	"'[^\\]'"
@@ -441,11 +450,16 @@ if exists("g:java_highlight_debug")
   syn match   javaDebugSpecial		contained "\\\%(u\x\x\x\x\|[0-3]\o\o\|\o\o\=\|[bstnfr"'\\]\)"
   syn region  javaDebugString		contained start=+"+ end=+"+ contains=javaDebugSpecial
   syn region  javaDebugString		contained start=+"""[ \t\x0c\r]*$+hs=e+1 end=+"""+he=s-1 contains=javaDebugSpecial,javaDebugTextBlockError
-  " The highlight groups of java{StrTempl,Debug{,Paren,StrTempl}}\,
-  " share one colour by default. Do not conflate unrelated parens.
-  syn region  javaDebugStrTemplEmbExp	contained matchgroup=javaDebugStrTempl start="\\{" end="}" contains=javaComment,javaLineComment,javaDebug\%(Paren\)\@!.*
-  exec 'syn region javaDebugStrTempl contained start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="+ end=+"+ contains=javaDebugStrTemplEmbExp,javaDebugSpecial'
-  exec 'syn region javaDebugStrTempl contained start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="""[ \t\x0c\r]*$+hs=e+1 end=+"""+he=s-1 contains=javaDebugStrTemplEmbExp,javaDebugSpecial,javaDebugTextBlockError'
+
+  if s:ff.IsRequestedPreviewFeature(430)
+    " The highlight groups of java{StrTempl,Debug{,Paren,StrTempl}}\,
+    " share one colour by default. Do not conflate unrelated parens.
+    syn region javaDebugStrTemplEmbExp	contained matchgroup=javaDebugStrTempl start="\\{" end="}" contains=javaComment,javaLineComment,javaDebug\%(Paren\)\@!.*
+    exec 'syn region javaDebugStrTempl contained start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="+ end=+"+ contains=javaDebugStrTemplEmbExp,javaDebugSpecial'
+    exec 'syn region javaDebugStrTempl contained start=+\%(\.[[:space:]\n]*\)\@' . s:ff.Peek('80', '') . '<="""[ \t\x0c\r]*$+hs=e+1 end=+"""+he=s-1 contains=javaDebugStrTemplEmbExp,javaDebugSpecial,javaDebugTextBlockError'
+    hi def link javaDebugStrTempl	Macro
+  endif
+
   syn match   javaDebugTextBlockError	contained +"""\s*"""+
   syn match   javaDebugCharacter	contained "'[^\\]'"
   syn match   javaDebugSpecialCharacter contained "'\\.'"
@@ -471,7 +485,6 @@ if exists("g:java_highlight_debug")
 
   hi def link javaDebug			Debug
   hi def link javaDebugString		DebugString
-  hi def link javaDebugStrTempl		Macro
   hi def link javaDebugTextBlockError	Error
   hi def link javaDebugType		DebugType
   hi def link javaDebugBoolean		DebugBoolean
@@ -580,7 +593,6 @@ hi def link javaSpecial			Special
 hi def link javaSpecialError		Error
 hi def link javaSpecialCharError	Error
 hi def link javaString			String
-hi def link javaStrTempl		Macro
 hi def link javaCharacter		Character
 hi def link javaSpecialChar		SpecialChar
 hi def link javaNumber			Number
diff --git a/runtime/syntax/testdir/dumps/java_previews_430_00.dump b/runtime/syntax/testdir/dumps/java_previews_430_00.dump
new file mode 100644
index 0000000000..199bac05ca
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/java_previews_430_00.dump
@@ -0,0 +1,20 @@
+>/+0#0000e05#ffffff0@1| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|j|a|v|a|_|s|y|n|t|a|x|_|p|r|e|v|i|e|w|s| |=| |[|4|3|0|]| +0#0000000&@22
+@75
+@75
+@75
+|c+0#00e0003&|l|a|s@1| +0#0000000&|S|t|r|i|n|g|T|e|m|p|l|a|t|e|T|e|s|t|s| @2|/+0#0000e05&@1| |J|D|K| |2|1|+| |(|-@1|e|n|a|b|l|e|-|p|r|e|v|i|e|w| |-@1|r|e|l|e|a|s|e| |2|1|)|.| +0#0000000&@3
+|{| @73
+@4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|{| @62
+@8|S|y|s|t|e|m|.|o|u|t|.|p|r|i|n|t|l|n|(|S|T|R|.|"@2| @40
+| +0#e000e06&@7|"| +0#0000000&@65
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&| +0#0000000&@57
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@40
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&|"| +0#0000000&@39
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|\|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@26
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@29
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"@1| +0#0000000&@43
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"@1|\|"|"+0#0000000&@2|)|;| @36
+@75
+@8|S|t|r|i|n|g| |w|o@1|f| |=| |"+0#e000002&|W|o@1|f|"|,+0#0000000&| |d|o|g| |=| |"+0#e000002&|d|o|g|"|,+0#0000000&| |f|o|x| |=| |"+0#e000002&|f|o|x|"|;+0#0000000&| @19
+@75
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/java_string_03.dump b/runtime/syntax/testdir/dumps/java_previews_430_01.dump
similarity index 83%
rename from runtime/syntax/testdir/dumps/java_string_03.dump
rename to runtime/syntax/testdir/dumps/java_previews_430_01.dump
index 9e88372b28..edc9697101 100644
--- a/runtime/syntax/testdir/dumps/java_string_03.dump
+++ b/runtime/syntax/testdir/dumps/java_previews_430_01.dump
@@ -1,14 +1,14 @@
 | +0#e000e06#ffffff0@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@29
 | +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"@1| +0#0000000&@43
-| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"@1|\|"|"+0#0000000&@2|)|;| @5|/+0#0000e05&@1| |J|D|K| |2|1|+|.| +0#0000000&@19
+| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"@1|\|"|"+0#0000000&@2|)|;| @36
 @75
 @8|S|t|r|i|n|g| |w|o@1|f| |=| |"+0#e000002&|W|o@1|f|"|,+0#0000000&| |d|o|g| |=| |"+0#e000002&|d|o|g|"|,+0#0000000&| |f|o|x| |=| |"+0#e000002&|f|o|x|"|;+0#0000000&| @19
 > @74
-@8|S|t|r|i|n|g| |s|6| |=| |S|T|R| @51
+@8|S|t|r|i|n|g| |s|1| |=| |S|T|R| @51
 @12|.|"+0#e000e06&|A| |q|u|i|c|k| |b|r|o|w|n| |\|{|f+0#0000000&|o|x|}+0#e000e06&| |j|u|m|p|s| |o|v|e|r| |t|h|e| |l|a|z|y| |\|{|d+0#0000000&|o|g|}+0#e000e06&|"|;+0#0000000&| @11
-@8|S|t|r|i|n|g| |s|7| |=| |S|T|R|.|p|r|o|c|e|s@1|(|S|t|r|i|n|g|T|e|m|p|l|a|t|e|.|R|A|W| @24
+@8|S|t|r|i|n|g| |s|2| |=| |S|T|R|.|p|r|o|c|e|s@1|(|S|t|r|i|n|g|T|e|m|p|l|a|t|e|.|R|A|W| @24
 @12|.|"+0#e000e06&|\|"|\|{|w+0#0000000&|o@1|f|}+0#e000e06&|\|s|!|\|"@1|)+0#0000000&|;| @43
-@8|S|t|r|i|n|g| |s|8| |=| |S|T|R|.|"@2| @47
+@8|S|t|r|i|n|g| |s|3| |=| |S|T|R|.|"@2| @47
 | +0#e000e06&@11|A|\|s|\| +0#0000000&@58
 | +0#e000e06&@11|q|u|i|c|k| |\| +0#0000000&@55
 | +0#e000e06&@11|b|r|o|w|n|\|s|\| +0#0000000&@54
@@ -17,4 +17,4 @@
 | +0#e000e06&@11|o|v|e|r| |\| +0#0000000&@56
 | +0#e000e06&@11|t|h|e|\|s|\| +0#0000000&@56
 | +0#e000e06&@11|l|a|z|y| |\| +0#0000000&@56
-@57|5@1|,|0|-|1| @7|5|7|%| 
+@57|1|9|,|0|-|1| @7|2|6|%| 
diff --git a/runtime/syntax/testdir/dumps/java_string_04.dump b/runtime/syntax/testdir/dumps/java_previews_430_02.dump
similarity index 80%
rename from runtime/syntax/testdir/dumps/java_string_04.dump
rename to runtime/syntax/testdir/dumps/java_previews_430_02.dump
index 4336a92b2d..fe1e951455 100644
--- a/runtime/syntax/testdir/dumps/java_string_04.dump
+++ b/runtime/syntax/testdir/dumps/java_previews_430_02.dump
@@ -1,20 +1,20 @@
 | +0#e000e06#ffffff0@11|l|a|z|y| |\| +0#0000000&@56
 | +0#e000e06&@11|\|{|d+0#0000000&|o|g|}+0#e000e06&|"+0#0000000&@2|;| @52
-@8|S|t|r|i|n|g| |s|9| |=| |S|T|R|.|p|r|o|c|e|s@1|(|S|t|r|i|n|g|T|e|m|p|l|a|t|e|.|R|A|W| @24
+@8|S|t|r|i|n|g| |s|4| |=| |S|T|R|.|p|r|o|c|e|s@1|(|S|t|r|i|n|g|T|e|m|p|l|a|t|e|.|R|A|W| @24
 @12|.| @61
 @12|"@2| @59
 | +0#e000e06&@11>"|\|{|w+0#0000000&|o@1|f|}+0#e000e06&|\|s|!|\|"|"+0#0000000&@2|)|;| @44
-@8|S|t|r|i|n|g| |s|1|0| |=| |j|a|v|a|.|u|t|i|l|.|F|o|r|m|a|t|P|r|o|c|e|s@1|o|r|.|F|M|T| @24
+@8|S|t|r|i|n|g| |s|5| |=| |j|a|v|a|.|u|t|i|l|.|F|o|r|m|a|t|P|r|o|c|e|s@1|o|r|.|F|M|T| @25
 @12|.| |"+0#e000e06&|%|-|1|4|s|\|{|"+0#e000002&|A|\+0#e000e06&|s|"+0#e000002&| +0#0000000&|+| |S|T|R| |.| |"+0#e000e06&|q|u|i|c|k|"| +0#0000000&|+| |"+0#e000002&|b|r|o|w|n|"|}+0#e000e06&|%|s|\|{|f+0#0000000&|o|x|}+0#e000e06&| |"| +0#0000000&@10
 @12|+| |j|a|v|a|.|u|t|i|l|.|F|o|r|m|a|t|P|r|o|c|e|s@1|o|r|.|F|M|T| @31
 @12|.| |"+0#e000e06&|%|-|2|0|s|\|{|"+0#e000002&|j|u|m|p|s|\+0#e000e06&|s|o+0#e000002&|v|e|r| |t|h|e|\+0#e000e06&|s|"+0#e000002&| +0#0000000&@33
 @20|+| |S|T|R| |.| |"+0#e000e06&|l|a|z|y|"|}|%|s|\|{|d+0#0000000&|o|g|}+0#e000e06&|"|;+0#0000000&| @29
-@8|S|t|r|i|n|g| |s|1@1| |=| |S|T|R|.|"@2| @46
+@8|S|t|r|i|n|g| |s|6| |=| |S|T|R|.|"@2| @47
 | +0#e000e06&@11|\|"|\|{| +0#0000000&@11|/+0#0000e05&@1| |A| |n|e|s|t|e|d| |c|o|m@1|e|n|t|.| +0#0000000&@26
 @8|(|n+0#af5f00255&|e|w| +0#0000000&|j|a|v|a|.|u|t|i|l|.|f|u|n|c|t|i|o|n|.|F|u|n|c|t|i|o|n|<|S|t|r|i|n|g|,| |S|t|r|i|n|g|>|(|)| |{| @14
 @12|p+0#00e0003&|u|b|l|i|c| +0#0000000&|S|t|r|i|n|g| |a|p@1|l|y|(|S|t|r|i|n|g| |b|a|y|)| |{| |r+0#af5f00255&|e|t|u|r|n| +0#0000000&|b|a|y|;| |}|;| @14
 @8|}|)|.|a|p@1|l|y|(|w|o@1|f|)| @52
 @12|}+0#e000e06&|\|s|!|\|"|"+0#0000000&@2|;| @52
-@8|S|t|r|i|n|g| |s|1|2| |=| |j|a|v|a|.|u|t|i|l|.|F|o|r|m|a|t|P|r|o|c|e|s@1|o|r|.|F|M|T| @24
+@8|S|t|r|i|n|g| |s|7| |=| |j|a|v|a|.|u|t|i|l|.|F|o|r|m|a|t|P|r|o|c|e|s@1|o|r|.|F|M|T| @25
 @12|.|"@2| @58
-@57|7|3|,|4|-|1|3| @6|7|8|%| 
+@57|3|7|,|4|-|1|3| @6|6|3|%| 
diff --git a/runtime/syntax/testdir/dumps/java_string_05.dump b/runtime/syntax/testdir/dumps/java_previews_430_03.dump
similarity index 94%
rename from runtime/syntax/testdir/dumps/java_string_05.dump
rename to runtime/syntax/testdir/dumps/java_previews_430_03.dump
index 47804a9393..df2afa2181 100644
--- a/runtime/syntax/testdir/dumps/java_string_05.dump
+++ b/runtime/syntax/testdir/dumps/java_previews_430_03.dump
@@ -10,11 +10,11 @@
 | +0#e000e06&@15|t|h|e|\|s|\| +0#0000000&@52
 | +0#e000e06&@15|\|{| +0#0000000&|"+0#e000002&|l|a|z|y|"| +0#0000000&|}+0#e000e06&| |"+0#0000000&@2|}+0#e000e06&|\| +0#0000000&@41
 | +0#e000e06&@11|%|s|\|{| +0#0000000&|d|o|g| |}+0#e000e06&|"+0#0000000&@2|;| @48
-@8|S|t|r|i|n|g| |s|1|3| |=| |S|T|R| @50
+@8|S|t|r|i|n|g| |s|8| |=| |S|T|R| @51
 @12|.|"+0#e000e06&|\|"|\|{| +0#0000000&@9|/+0#0000e05&|*| |A| |n|e|s|t|e|d| |c|o|m@1|e|n|t|.| |*|/| +0#0000000&@23
 @8|(@1|j|a|v|a|.|u|t|i|l|.|f|u|n|c|t|i|o|n|.|F|u|n|c|t|i|o|n|<|S|t|r|i|n|g|,| |S|t|r|i|n|g|>|)| |b|a|y| |-|>| |b|a|y|)| @8
 @28|.|a|p@1|l|y|(|w|o@1|f|)| @34
 @12|}+0#e000e06&|\|s|!|\|"@1|;+0#0000000&| @54
 @4|}| @69
 |}| @73
-@57|9|1|,|4|-|1|3| @6|B|o|t| 
+@57|5@1|,|4|-|1|3| @6|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/java_string_00.dump b/runtime/syntax/testdir/dumps/java_string_00.dump
index 0d2f148f2d..b973226f13 100644
--- a/runtime/syntax/testdir/dumps/java_string_00.dump
+++ b/runtime/syntax/testdir/dumps/java_string_00.dump
@@ -1,4 +1,4 @@
->c+0#00e0003#ffffff0|l|a|s@1| +0#0000000&|S|t|r|i|n|g|T|e|s|t|s| @2|/+0#0000e05&@1| |J|D|K| |2|1|+| |(|-@1|e|n|a|b|l|e|-|p|r|e|v|i|e|w| |-@1|r|e|l|e|a|s|e| |2|1|)|.| +0#0000000&@11
+>c+0#00e0003#ffffff0|l|a|s@1| +0#0000000&|S|t|r|i|n|g|T|e|s|t|s| @57
 |{| @73
 @4|s+0#00e0003&|t|a|t|i|c| +0#0000000&|{| @62
 @8|S|t|r|i|n|g| |s|1| |=| |"+0#e000002&|A| |q|u|i|c|k| |b|r|o|w|n| |f|o|x| |j|u|m|p|s| |o|v|e|r| |t|h|e| |l|a|z|y| |d|o|g|"|;+0#0000000&| @10
diff --git a/runtime/syntax/testdir/dumps/java_string_01.dump b/runtime/syntax/testdir/dumps/java_string_01.dump
index 84b6494589..d7035611a7 100644
--- a/runtime/syntax/testdir/dumps/java_string_01.dump
+++ b/runtime/syntax/testdir/dumps/java_string_01.dump
@@ -17,4 +17,4 @@
 @8|/+0#0000e05&@1| |T|h|e|r|e| |a|r|e| |S|P|A|C|E|,| |F@1|,| |H|T|,| |C|R|,| |a|n|d| |L|F| |a|f|t|e|r| |"@2|.| +0#0000000&@17
 @8|S|t|r|i|n|g| |e|m|p|t|y| |=| |"@2| |^+0#0000e05&|L| +0#0000000&@2|^+0#0000e05&|M| +0#0000000&@40
 | +0#e000002&@11|"+0#0000000&@2|;| @58
-@57|1|9|,|3|-|9| @7|1|5|%| 
+@57|1|9|,|3|-|9| @7|5|2|%| 
diff --git a/runtime/syntax/testdir/dumps/java_string_02.dump b/runtime/syntax/testdir/dumps/java_string_02.dump
index ef6549f55a..e0b0ae08e3 100644
--- a/runtime/syntax/testdir/dumps/java_string_02.dump
+++ b/runtime/syntax/testdir/dumps/java_string_02.dump
@@ -9,12 +9,12 @@
 | +0#e000002&@7|"@1|\+0#e000e06&|"|"+0#e000002&@1|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1| +0#0000000&@48
 | +0#e000002&@7|"@1|\+0#e000e06&|"|"+0#e000002&@1|\+0#e000e06&|"|"+0#e000002&| +0#0000000&@57
 | +0#e000002&@7|"@1|\+0#e000e06&|"|"+0#e000002&@1|\+0#e000e06&|"|"+0#e000002&|\+0#e000e06&|"|"+0#0000000&@2|)|;| @50
-@75
-@8|S|y|s|t|e|m|.|o|u|t|.|p|r|i|n|t|l|n|(|S|T|R|.|"@2| @40
-| +0#e000e06&@7|"| +0#0000000&@65
-| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&| +0#0000000&@57
-| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@40
-| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&|"| +0#0000000&@39
-| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|\|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@26
-| +0#e000e06&@7|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|"|\|{|"+0#e000002&|\+0#e000e06&|"|\|"|"+0#e000002&|}+0#e000e06&|\|{|"+0#e000002&|\+0#e000e06&|u|0@1|5|c|\|u|0@1|2@1|"+0#e000002&|}+0#e000e06&| +0#0000000&@29
-@57|3|7|,|3|-|9| @7|3|6|%| 
+@4|}| @69
+|}| @73
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|3|7|,|3|-|9| @7|B|o|t| 
diff --git a/runtime/syntax/testdir/input/java_previews_430.java b/runtime/syntax/testdir/input/java_previews_430.java
new file mode 100644
index 0000000000..15d8ba2cea
--- /dev/null
+++ b/runtime/syntax/testdir/input/java_previews_430.java
@@ -0,0 +1,68 @@
+// VIM_TEST_SETUP let g:java_syntax_previews = [430]
+
+
+
+class StringTemplateTests	// JDK 21+ (--enable-preview --release 21).
+{
+	static {
+		System.out.println(STR."""
+		"
+		\{"\"\""}
+		\{"\"\""}\{"\u005c\u0022"}
+		\{"\"\""}\{"\u005c\u0022"}"
+		\{"\"\""}\"\{"\u005c\u0022\u005c\u0022"}
+		\{"\"\""}\"\{"\"\""}\{"\u005c\u0022"}
+		\{"\"\""}\"\{"\"\""}\""
+		\{"\"\""}\"\{"\"\""}\""\"""");
+
+		String woof = "Woof", dog = "dog", fox = "fox";
+
+		String s1 = STR
+			."A quick brown \{fox} jumps over the lazy \{dog}";
+		String s2 = STR.process(StringTemplate.RAW
+			."\"\{woof}\s!\"");
+		String s3 = STR."""
+			A\s\
+			quick \
+			brown\s\
+			\{fox} \
+			jumps\s\
+			over \
+			the\s\
+			lazy \
+			\{dog}""";
+		String s4 = STR.process(StringTemplate.RAW
+			.
+			"""
+			"\{woof}\s!\"""");
+		String s5 = java.util.FormatProcessor.FMT
+			. "%-14s\{"A\s" + STR . "quick" + "brown"}%s\{fox} "
+			+ java.util.FormatProcessor.FMT
+			. "%-20s\{"jumps\sover the\s"
+					+ STR . "lazy"}%s\{dog}";
+		String s6 = STR."""
+			\"\{			// A nested comment.
+		(new java.util.function.Function<String, String>() {
+			public String apply(String bay) { return bay; };
+		}).apply(woof)
+			}\s!\"""";
+		String s7 = java.util.FormatProcessor.FMT
+			."""
+			%-14s\{STR."""
+				A\s\
+				\{ "quick" } \
+				brown"""}\
+			%s\{ fox } \
+			%-20s\{STR."""
+				jumps\s\
+				over \
+				the\s\
+				\{ "lazy" } """}\
+			%s\{ dog }""";
+		String s8 = STR
+			."\"\{			/* A nested comment. */
+		((java.util.function.Function<String, String>) bay -> bay)
+							.apply(woof)
+			}\s!\"";
+	}
+}
diff --git a/runtime/syntax/testdir/input/java_string.java b/runtime/syntax/testdir/input/java_string.java
index 43a7a050ca..51c30b9da8 100644
--- a/runtime/syntax/testdir/input/java_string.java
+++ b/runtime/syntax/testdir/input/java_string.java
@@ -1,4 +1,4 @@
-class StringTests	// JDK 21+ (--enable-preview --release 21).
+class StringTests
 {
 	static {
 		String s1 = "A quick brown fox jumps over the lazy dog";
@@ -40,65 +40,5 @@ class StringTests	// JDK 21+ (--enable-preview --release 21).
 		""\"""\u005c\u0022
 		""\"""\""
 		""\"""\""\"""");
-
-		System.out.println(STR."""
-		"
-		\{"\"\""}
-		\{"\"\""}\{"\u005c\u0022"}
-		\{"\"\""}\{"\u005c\u0022"}"
-		\{"\"\""}\"\{"\u005c\u0022\u005c\u0022"}
-		\{"\"\""}\"\{"\"\""}\{"\u005c\u0022"}
-		\{"\"\""}\"\{"\"\""}\""
-		\{"\"\""}\"\{"\"\""}\""\"""");		// JDK 21+.
-
-		String woof = "Woof", dog = "dog", fox = "fox";
-
-		String s6 = STR
-			."A quick brown \{fox} jumps over the lazy \{dog}";
-		String s7 = STR.process(StringTemplate.RAW
-			."\"\{woof}\s!\"");
-		String s8 = STR."""
-			A\s\
-			quick \
-			brown\s\
-			\{fox} \
-			jumps\s\
-			over \
-			the\s\
-			lazy \
-			\{dog}""";
-		String s9 = STR.process(StringTemplate.RAW
-			.
-			"""
-			"\{woof}\s!\"""");
-		String s10 = java.util.FormatProcessor.FMT
-			. "%-14s\{"A\s" + STR . "quick" + "brown"}%s\{fox} "
-			+ java.util.FormatProcessor.FMT
-			. "%-20s\{"jumps\sover the\s"
-					+ STR . "lazy"}%s\{dog}";
-		String s11 = STR."""
-			\"\{			// A nested comment.
-		(new java.util.function.Function<String, String>() {
-			public String apply(String bay) { return bay; };
-		}).apply(woof)
-			}\s!\"""";
-		String s12 = java.util.FormatProcessor.FMT
-			."""
-			%-14s\{STR."""
-				A\s\
-				\{ "quick" } \
-				brown"""}\
-			%s\{ fox } \
-			%-20s\{STR."""
-				jumps\s\
-				over \
-				the\s\
-				\{ "lazy" } """}\
-			%s\{ dog }""";
-		String s13 = STR
-			."\"\{			/* A nested comment. */
-		((java.util.function.Function<String, String>) bay -> bay)
-							.apply(woof)
-			}\s!\"";
 	}
 }