Refactoring extraction methods leads to syntax errors.

[provide a description of the issue]

Environment
-Operating System: Windows11
-JDK version: 17
-Visual Studio Code version: 1.88
-Java extension version: 1.29

Steps to Reproduce:

1. select " this.value = value;"
2. click “Refacator-Extract to method”

class ExtractMethodTest {
private final int value;
public ExtractMethodTest(int value) {
// extract method
this.value = value;
}
}

refactoring result：

Reason: The final field ExtractMethodTest.value cannot be assigned

Expected behavior: Check before and after refactoring, and issue a warning if there are syntax errors

首先，使用 JDK 17、VS Code 1.88 和 Java extension 1.29，在 Java 代码片段上复现提取方法重构。跟踪提取重构的入口点及其验证流程，然后确认能够检测到无效输出并发出警告，而不是静默地产生语法错误。