Remove SecurityManager - #248
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An example warning is |
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Currently, there's only one open source example of this feature being used: https://github.com/search?q=%3CallowSystemExits%3Efalse%3C%2FallowSystemExits%3E+language%3A%22Maven+POM%22&type=code&l=Maven+POM |
| /** | ||
| * Whether to allow System.exit() to be used. Should not be set to <code>false</code> when using parallel | ||
| * execution, as it isn't thread-safe. | ||
| * | ||
| * @since 1.2 | ||
| */ | ||
| @Parameter(defaultValue = "true") | ||
| protected boolean allowSystemExits; | ||
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As this would be a breaking change, keep it for a while and just print a warning for now. This way, users can fix their scripts.
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Yea, that's why I hadn't merged this -- Java isn't forcing me to yet.
Another option here might be to wrap the usage in if (Version.parseFromString(System.getProperty("java.version")).compareTo(new Version(24)) >=1) and print a warning if using a newer Java version that won't support it and ignore the option in that case. And in the meantime, print a warning and deprecate the parameter.
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I'm not sure when they're planning on removing this (I used 24 as an example). I don't think they've decided when that will be (or at least I can't find any documentation about it).
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Yes, it gets removed. The warning is there since 17 or 18.
Docs: https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/SecurityManager.html
@Deprecated(since="17",
forRemoval=true)
public class SecurityManager
extends Object
Deprecated, for removal: This API element is subject to removal in a future version.
The Security Manager is deprecated and subject to removal in a future release. There is no replacement for the Security Manager. See JEP 411 for discussion and alternatives.
There's more
https://openjdk.org/jeps/411
Description
In Java 17, we will:
Deprecate, for removal, most Security Manager related classes and methods.
Issue a warning message at startup if the Security Manager is enabled on the command line.
Issue a warning message at run time if a Java application or library installs a Security Manager dynamically.
In Java 18, we will prevent a Java application or library from dynamically installing a Security Manager unless the end user has explicitly opted to allow it.
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Another option here might be to wrap the usage in if (Version.parseFromString(System.getProperty("java.version")).compareTo(new Version(24)) >=1)
But that would still print a ClassNotFoundException on 24 or so. Unless:
- You use reflection. A lot.
- Create a multi release jar
- Drop it all together and print a warning
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I was thinking of using reflection
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I'd rather put that code into its own class.
Then, for Java 21+, create a Multi Release Jar which implements this as a no-op.
Easier to maintain, faster than reflection.
But still, why not start with a warning? 🤷🏻♂️ Ship early, ship often.
| if (!allowSystemExits) { | ||
| System.setSecurityManager(new NoExitSecurityManager()); | ||
| } |
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Print a warning in case this is false.
| if (!allowSystemExits) { | ||
| System.setSecurityManager(new NoExitSecurityManager()); | ||
| } |
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Same, keep var and print warning (to be removed in…)
| if (!allowSystemExits) { | ||
| System.setSecurityManager(new NoExitSecurityManager()); | ||
| } |
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Kind of fixes #286 but let me make another suggestion |
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Created #289 for printing a warning about the SystemManager deprecation |
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JEP 411 deprecated SecurityManager in Java 17, for future removal. It is unclear what it will be replaced with for the use case of preventing
System.exitusages. JDK-8199704 is one possibility, but it's unclear how likely that is to be implemented.We should prepare for it's removal by removing our dependency on it. This is a breaking change.