VSCode implicitly import java.lang.StringTemplate.STR which conflict with org.yaml.snakeyaml.nodes.Tag.STR

[renanfranca]

VSCode implicitly import java.lang.StringTemplate.STR which conflict with org.yaml.snakeyaml.nodes.Tag.STR

Environment

• Operating System: Windows 10
• JDK version: 21
• Visual Studio Code version: 1.86.2
• Java extension version: v1.28.1

Steps To Reproduce

1. Clone the open source project https://github.com/jhipster/jhipster-lite
2. Import the java project
3. Go to file tech.jhipster.lite.module.infrastructure.secondary.YamlFileSpringPropertiesHandler.java
4. See the compilation error (Type mismatch: cannot convert from StringTemplate.Processor<String,RuntimeException> to Tag)

[Screenshot]

Current Result

I have to change the code only to run the project:
FROM:

  private Node buildScalarNode(Object value) {
    Tag tag = STR;
    if (value instanceof Integer || value instanceof Long) {
      tag = INT;
    } else if (value instanceof Double || value instanceof Float) {
      tag = FLOAT;
    } else if (value instanceof Boolean) {
      tag = BOOL;
    }

    return new ScalarNode(tag, value.toString(), null, null, DumperOptions.ScalarStyle.PLAIN);
  }

TO:

  private Node buildScalarNode(Object value) {
    Tag tag = Tag.STR;
    if (value instanceof Integer || value instanceof Long) {
      tag = INT;
    } else if (value instanceof Double || value instanceof Float) {
      tag = FLOAT;
    } else if (value instanceof Boolean) {
      tag = BOOL;
    }

    return new ScalarNode(tag, value.toString(), null, null, DumperOptions.ScalarStyle.PLAIN);
  }

Expected Result

Is there a configuration to solve this problem without need to explicitly use Tag.STR?

Additional Informations

[rgrunber]

Reproducible in Eclipse & javac !

Eclipse

Tag.java

package org.example;
public class Tag {
	public static final String STR = "test";
}

Main.java

package org.sample;
import static org.example.Tag.STR;
public class Main {
	public static void main(String[] args) {
		String value = STR;
		System.out.println(value);
	}
}

/usr/lib/jvm/java-21-openjdk/bin/javac --enable-preview --release 21 org/sample/Main.java 
org/sample/Main.java:5: error: reference to STR is ambiguous
		String value = STR;
		               ^
  both variable STR in StringTemplate and variable STR in Tag match
1 error

I think this comes down to how String Templates are defined in (JEP 430). It says :

STR is a public static final field that is automatically imported into every Java source file.

So STR becomes a kind of "restricted keyword". I think it always needs to be fully qualified now.

[fbricon]

@rgrunber javac doesn't fail without the "--enable-preview" flag. Neither does IJ IDEA. So the bug here is to expose STR when preview features are disabled. Definitely an upstream JDT issue.

[rgrunber]

String Templates are a preview feature in Java 21 though. If --enable-preview is not included, it's reasonable to assume the STR field doesn't get automatically injected, hence no ambiguity.

Update: Ok, after thinking a bit ( 😜 ) I see your point. So users could use Java 21 (and eventually Java 22, it'll be preview there also) and if we disabled --enable-preview, it would continue to work. But what happens when the feature becomes finalized (ie. Java 23?). Then we can't protect them from the name clash.

[fbricon]

But what happens when the feature becomes finalized (ie. Java 23?). Then we can't protect them from the name clash.

Yes, but that's a Java 23 problem.

[rgrunber]

You're right. I forgot that managed projects (like Maven, Gradle) don't have preview features enabled by default. If preview features are disabled, and this is occuring then it's a bug in JDT Core.

[fbricon]

JEP 430 is dead. STR is no longer implicitly injected by ECJ into the compilation. We're good for now.