2 warnings

2 warnings

Compiled OK

Compiled OK

~/bin/jdk-11/bin/java R

/jdk-11/bin/java R

R[name=Hello World!]

R[name=Hello World!]

</source>

</source>

=== Can I use [[Frgaal]] via {{JDK|javax/tools|ToolProvider}} [[API]]? ===

=== Can I use [[Frgaal]] via {{JDK|javax/tools|ToolProvider}} [[API]]? ===

Let's imagine we have a following code (that invokes the {{JDK|javax/tool|JavaCompiler}} via {{JDK|javax/tool|ToolProvider}} for a custom ''CODE'' snippet defining {{JDK|java/lang|Record}} with main method:

Let's imagine we have a following code invoking the {{JDK|javax/tool|JavaCompiler}} via {{JDK|javax/tool|ToolProvider}} for a custom ''CODE'' snippet defining {{JDK|java/lang|Record}} with main method:

<source lang="java">

<source lang="java">

Can we fix that? Sure...

Can we fix that? Sure...

The idea would be to replace the standard "compiler tool" with the one coming from the [[frgaal]] project. Let's try to disable the regular compiler first. There is an option '''--limit-modules''' in [[JDK]]-11+ and the idea is to use it to use it to disable standard [[JavaC]]:

The idea would be to replace the standard "compiler tool" with the one coming from the [[frgaal]] project. Let's try to disable the regular compiler first. There is an option '''--limit-modules''' in [[JDK]]-11+ and the idea is to use it to disable standard [[JavaC]]:

<source lang="bash">

<source lang="bash">

^

^

</source>

</source>

The idea would be to replace the standard "compiler tool" with the one coming from the [[frgaal]] project. Let's try to disable the regular compiler first. There is an option '''--limit-modules''' in [[JDK]]-11+ and the idea is to use it to use it to disable standard [[JavaC]]:

The idea would be to replace the standard "compiler tool" with the one coming from the [[frgaal]] project. Let's try to disable the regular compiler first. There is an option '''--limit-modules''' in [[JDK]]-11+ and the idea is to use it to use it to disable standard [[JavaC]]:

class ModernJavaCompiler {

class ModernJavaCompiler {

private static final String CODE =

private static final String CODE = ""

"record R (String name) {\n"

+ "record R (String name) {\n"

+ " public static void main(String... args) {\n"

+ " public static void main(String... args) {\n"

+ " System.out.println(new R(\"Hello World!\"));\n"

+ " System.out.println(new R(\"Hello World!\"));\n"

class ModernJavaCompiler {

class ModernJavaCompiler {

private static final String CODE = "record R (String name) {\n"

private static final String CODE =

"record R (String name) {\n"

+ " public static void main(String... args) {\n"

+ " public static void main(String... args) {\n"

+ " System.out.println(new R(\"Hello World!\"));\n"

+ " System.out.println(new R(\"Hello World!\"));\n"

=== Can I use [[Frgaal]] via {{JDK|javax/tools|ToolProvider}} [[API]]? ===

=== Can I use [[Frgaal]] via {{JDK|javax/tools|ToolProvider}} [[API]]? ===

Let's imagine we have a following code (that invokes the {{JDK|javax/tool|JavaCompiler}} via {{JDK|javax/tool|ToolProvider}} for a custom ''CODE'' snippet that uses [[JDK]]17 {{JDK|java/lang|Record}}:

Let's imagine we have a following code (that invokes the {{JDK|javax/tool|JavaCompiler}} via {{JDK|javax/tool|ToolProvider}} for a custom ''CODE'' snippet defining {{JDK|java/lang|Record}} with main method:

<source lang="java">

<source lang="java">

I love [http://frgaal.org Frgaal] and you'll love it too: Wouldn't it be great to have '''record'''s and other latest [[Java]] language features available on your old JDK? As old as JDK8? [[Frgaal]] allows you to do it. There is a [[Maven]] plugin, integration with [[Gradle]], a way to use it from command line... read more at http://frgaal.org

I love [http://frgaal.org Frgaal] and you'll love it too: Wouldn't it be great to have '''record'''s and other latest [[Java]] language features available on your old [[JDK]]s? As old as [[JDK]]8? [[Frgaal]] allows you to do it. There is a [[Maven]] plugin, integration with [[Gradle]], a way to use it from command line... read more at http://frgaal.org

I love [http://frgaal.org Frgaal] and you'll love it too: Wouldn't it be great to have the latest [[Java]] language features available on your old JDK? As old as JDK8? [[Frgaal]] allows you to do it. There is a [[Maven]] plugin, integration with [[Gradle]], a way to use it from command line... read more at http://frgaal.org

I love [http://frgaal.org Frgaal] and you'll love it too: Wouldn't it be great to have '''record'''s and other latest [[Java]] language features available on your old JDK? As old as JDK8? [[Frgaal]] allows you to do it. There is a [[Maven]] plugin, integration with [[Gradle]], a way to use it from command line... read more at http://frgaal.org

=== Can I use [[Frgaal]] via {{JDK|javax/tools|ToolProvider}} [[API]]? ===

=== Can I use [[Frgaal]] via {{JDK|javax/tools|ToolProvider}} [[API]]? ===

Given following code (that invokes the {{JDK|javax/tool|JavaCompiler}} via {{JDK|javax/tool|ToolProvider}} for a custom ''CODE'' snippet that uses [[JDK]]17 {{JDK|java/lang|Record}}:

Let's imagine we have a following code (that invokes the {{JDK|javax/tool|JavaCompiler}} via {{JDK|javax/tool|ToolProvider}} for a custom ''CODE'' snippet that uses [[JDK]]17 {{JDK|java/lang|Record}}:

<source lang="java">

<source lang="java">

class ModernJavaCompiler {

class ModernJavaCompiler {

private static final String CODE = "record R (String name) {}";

private static final String CODE = "record R (String name) {\n"

+ " }\n"

+ "}\n";

public static void main(String... args) throws Exception {

public static void main(String... args) throws Exception {

JavaCompiler compiler = javax.tools.ToolProvider.getSystemJavaCompiler();

JavaCompiler compiler = javax.tools.ToolProvider.getSystemJavaCompiler();

List<String> itrbl = Arrays.asList("-source", "17", "-target", "8");

List<String> arguments = Arrays.asList(args);

List<String> itrbl1 = null;

List<JavaFileObject> sources = Collections.singletonList(new Src(CODE));

List<JavaFileObject> itrbl2 = Collections.singletonList(new Src(CODE));

JavaCompiler.CompilationTask task = compiler.getTask(null, null, null, arguments, null, sources);

JavaCompiler.CompilationTask task = compiler.getTask(null, null, null, itrbl, itrbl1, itrbl2);

Boolean res = task.call();

Boolean res = task.call();

if (!Boolean.TRUE.equals(res)) {

if (!Boolean.TRUE.equals(res)) {

</source>

</source>

This is a Java class that can be compiled using

This is a regular Java source file that can be compiled using standard [[Javac]] compiler:

<source lang="bash">

<source lang="bash">

javac -source 8 -target 8 ModernJavaCompiler.java

$ javac -source 8 -target 8 ModernJavaCompiler.java

</source>

</source>

Then it can be executed on [[JDK]]-17 as

It can be executed [[JDK]]-17 as

<source lang="bash">

<source lang="bash">

$ /jdk-17/bin/java ModernJavaCompiler

$ /jdk-17/bin/java ModernJavaCompiler

Compiled OK

Compiled OK

</source>

</source>

However executing the same code on [[JDK]]-11 is going to fail (as the [[Javac]] from [[JDK]]-11 doesn't support -source 17):

However executing the same steps with [[JDK]]-11 is going to fail as the [[Javac]] from [[JDK]]-11 doesn't support '''record''' keyword:

<source lang="bash">

<source lang="bash">

$ /jdk11/bin/java ModernJavaCompiler

$ /jdk11/bin/java ModernJavaCompiler

Exception in thread "main" java.lang.IllegalArgumentException: error: invalid source release: 17

Code.java:1: error: class, interface, or enum expected

at jdk.compiler/com.sun.tools.javac.main.Arguments.error(Arguments.java:907)

record R (String name) {

at jdk.compiler/com.sun.tools.javac.main.Arguments.doProcessArgs(Arguments.java:383)

</source>

</source>

The idea would be to replace the standard "compiler tool" with one coming from the [[frgaal]]. Let's try to disable the regular compiler first. There is an option '''--limit-modules''' in [[JDK]]-11+ and the idea is to use it to use it to disable standard [[JavaC]]:

The idea would be to replace the standard "compiler tool" with the one coming from the [[frgaal]] project. Let's try to disable the regular compiler first. There is an option '''--limit-modules''' in [[JDK]]-11+ and the idea is to use it to use it to disable standard [[JavaC]]:

<source lang="bash">

<source lang="bash">

</source>

</source>

Great! The disabling works. The "compiler tool" is completely missing. Now there is a time to inject [[Frgaal]] instead. Following script shows how to get it all working:

Great! Disabling works. The "compiler tool" is completely missing. Now there is a time to inject [[Frgaal]] instead. Following script shows how to get it all working:

<source lang="bash">

<source lang="bash">

2 warnings

2 warnings

Compiled OK

Compiled OK

</source>

</source>

E.g. it is necessary to provide extra {{JDK|java/util|ServiceLoader}} registration in ''META-INF/services'' path on the class path, but then it seems to run. Embed [[Frgaal]] into your own programs and use the latest [[Java]] features on any [[JDK]]!

 

Having '''record''' (and other [[JDK]]-18 language features) available on old JDKs is great, isn't it? All that is necessary is to provide extra {{JDK|java/util|ServiceLoader}} registration in ''META-INF/services'' path on the class path. Then the [[Frgaal]] compiler gets picked up and is used for compilation even on older [[JDK]]s.

 

 

Embed [[Frgaal]] into your own programs and use the latest [[Java]] features on any [[JDK]]!