关于Glassfish 4.0与Java 9兼容及NetBeans 8.0.2配置的技术问询

Hey there, let's tackle your questions thoroughly based on real-world experience and official compatibility notes:

1. Does Glassfish 4.0 support Java 9.0? #

Short answer: No, it does not.

Glassfish 4.0 was released well before Java 9 launched, and its official compatibility only extends up to Java 8. Java 9 introduced major changes like the module system (JPMS), stricter reflection access rules, and deprecated APIs that Glassfish 4.0's codebase wasn't designed to handle. Attempting to run Glassfish 4.0 on Java 9 will lead to runtime errors, classpath conflicts, and broken functionality (e.g., deployment failures, missing container services).

If you need to use Java 9, your best bet is to upgrade to Glassfish 5.0 or later—these versions were explicitly built to support Java 9+ features.

2. Does NetBeans 8.0.2 support Java 9? How to configure it (and fix Jar loading issues)? #

NetBeans 8.x (including 8.0.2) was originally designed for Java 7 and 8, so official Java 9 support is not available. That said, you can force basic compatibility with manual tweaks, but be warned: some core features (like code completion, debugging, or plugin functionality) may be unstable. Here's how to set it up and fix Jar loading problems:

Step 1: Set NetBeans to use Java 9 as its runtime #

1. Locate your NetBeans installation directory, then navigate to the etc folder.
2. Open the netbeans.conf file in a text editor.
3. Find the line starting with netbeans_jdkhome and update it to point to your Java 9 JDK installation path:

   netbeans_jdkhome="/path/to/your/jdk-9"
   

   (Example for Windows: netbeans_jdkhome="C:\Program Files\Java\jdk-9"; for macOS: netbeans_jdkhome="/Library/Java/JavaVirtualMachines/jdk-9.jdk/Contents/Home")
4. Save the file and restart NetBeans.

Step 2: Fix Jar loading issues (Java 9 module system conflicts) #

The Jar loading failure you're seeing is almost certainly due to Java 9's module system blocking access to legacy non-modular Jars. To resolve this:

• Open your project in NetBeans, right-click it and select Properties.
• Go to the Run tab, then find the VM Options field.
• Add the following parameters (adjust based on your project's dependencies):
  • If your project uses standard Java EE APIs (like servlets, JSPs), add:

    --add-modules java.se.ee
    

  • For Jars that rely on reflection access to internal JDK APIs, add specific --add-opens flags. For example, if a Jar needs access to java.lang.reflect, use:

    --add-opens java.base/java.lang.reflect=ALL-UNNAMED
    

  • If your Jars are non-modular, ensure they're added to the Classpath (not the Modulepath) in the project's Libraries tab. NetBeans 8.0.2 may default to Modulepath for newer JDKs, which breaks legacy Jars.

Critical Note #

Even with these tweaks, you'll likely encounter occasional bugs or missing features. For full, stable Java 9 support, upgrade to NetBeans 9.0 or later—these versions were built to handle JPMS and Java 9's changes natively.

内容的提问来源于stack exchange，提问作者Sudhakar Chavali