RFR: 8298266: "java.home property not set" error in Graal when sun.awt.fontconfig java property is set on Windows [v2]

[Alexander Scherbatiy]

On Thu, 22 Dec 2022 10:57:15 GMT, Alexander Scherbatiy <alexsch at openjdk.org> wrote:

>> **Environment**: 
>> GraalVM 22.3.0 with  jdk 19, Windows OS.
>> 
>> **Description**:
>> Create a native image of Swing application using GraalVM and run it with ` -Dsun.awt.fontconfig=fontconfig.properties.src` java property.
>> `java.lang.Error: java.home property not set` error is thrown.
>> 
>> For more details see https://github.com/oracle/graal/issues/4875.
>> 
>> **Solution**:
>> The error is thrown by the code from [FontConfiguration.findFontConfigFile()](https://github.com/openjdk/jdk19u/blob/c9d485792b99233f381dcdfd69838e7b973909bd/src/java.desktop/share/classes/sun/awt/FontConfiguration.java#L175) method.
>> GraalVM does not set `java.home`  property, that is why the `java.lang.Error: java.home property not set` is thrown.
>> `FontConfiguration.findFontConfigFile()` method compares `java.home` property to null before checking user provided `sun.awt.fontconfig` java property.
>> 
>> The proposed fix swaps the order of `java.home` and `sun.awt.fontconfig` properties checking to avoid using `java.home` property in case `sun.awt.fontconfig` is set.
>> 
>> 
>> **Steps to reproduce**:
>> - Download graal 22.3.0 jdk 19 for Windows from [GraalVM Community Edition 22.3.0](https://github.com/graalvm/graalvm-ce-builds/releases/tag/vm-22.3.0) page.
>> - Install native-image
>> 
>> graalvm-ce-java19-22.3.0\bin\gu.cmd install native-image
>> 
>> - Create and compile `SwingSample.java` sample
>> 
>> import java.awt.*;
>> import javax.swing.*;
>> 
>> public class SwingSample {
>>     public static void main(String[] args) throws Exception {
>>         SwingUtilities.invokeAndWait(() -> {
>> 
>>             JFrame frame = new JFrame("Hello World");
>> 
>>             JButton button = new JButton("Hello");
>>             button.addActionListener(e -> {
>>                 System.out.printf("Hello, World!%n");
>>             });
>> 
>>             JPanel panel = new JPanel(new FlowLayout());
>>             panel.add(button);
>> 
>>             frame.add(panel);
>>             frame.setSize(400, 300);
>>             frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
>>             frame.setVisible(true);
>>         });
>>     }
>> }
>> 
>> - Run native-image-agent to generate configuration files
>> 
>> graalvm-ce-java19-22.3.0\bin\java.cmd -agentlib:native-image-agent=config-output-dir=conf-dir SwingSample
>> 
>> - Copy `graalvm-ce-java19-22.3.0\lib\fontconfig.properties.src` file to the sample dir
>> - Generate native image with configuration files and `-Djava.awt.headless=false `, `-Dsun.awt.fontconfig=fontconfig.properties.src` java properties
>> 
>> call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64"
>> graalvm-ce-java19-22.3.0\bin\native-image.cmd --no-fallback -Djava.awt.headless=false -Dsun.awt.fontconfig=fontconfig.properties.src -H:ResourceConfigurationFiles=conf-dir/resource-config.json -H:SerializationConfigurationFiles=conf-dir/serialization-config.json -H:ReflectionConfigurationFiles=conf-dir/reflect-config.json -H:JNIConfigurationFiles=conf-dir/jni-config.json SwingSample
>> 
>> - Run the native image with `-Dsun.awt.fontconfig=fontconfig.properties.src` java property.
>> 
>> swingsample.exe  -Dsun.awt.fontconfig=fontconfig.properties.src
>> 
>> Exception in thread "main" java.lang.reflect.InvocationTargetException
>>         at java.desktop at 19.0.1/java.awt.EventQueue.invokeAndWait(EventQueue.java:1371)
>>         at java.desktop at 19.0.1/java.awt.EventQueue.invokeAndWait(EventQueue.java:1346)
>>         at java.desktop at 19.0.1/javax.swing.SwingUtilities.invokeAndWait(SwingUtilities.java:1480)
>>         at SwingSample.main(SwingSample.java:7)
>> Caused by: java.lang.Error: java.home property not set
>>         at java.desktop at 19.0.1/sun.awt.FontConfiguration.findFontConfigFile(FontConfiguration.java:180)
>>         at java.desktop at 19.0.1/sun.awt.FontConfiguration.<init>(FontConfiguration.java:97)
>>         at java.desktop at 19.0.1/sun.awt.windows.WFontConfiguration.<init>(WFontConfiguration.java:41)
>
> Alexander Scherbatiy has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Initialize javaLib when a user fontconfig file is set

There is the `Java system properties are inconsistent between traditional JDK and native image` issue in Graal: https://github.com/oracle/graal/issues/2835

With comment: https://github.com/oracle/graal/issues/2835#issuecomment-1333300103
> We are still not setting the `java.home` system property at image run time by default, and do not plan to change that. Because there is just no "JDK home directory" around at image run time, so setting `java.home` to, for example, the directory where the native image is located in is misleading - files that might be expected to be in that directory are not there.

-------------

PR: https://git.openjdk.org/jdk/pull/11559