一段 spring context 的 threadlocal 的用法

instance-threadlocal.java

private final ThreadLocal<TestContext> testContextHolder = ThreadLocal.withInitial(
			// Implemented as an anonymous inner class instead of a lambda expression due to a bug
			// in Eclipse IDE: "The blank final field testContext may not have been initialized"
			new Supplier<TestContext>() {
				@Override
				public TestContext get() {
					return copyTestContext(TestContextManager.this.testContext);
				}
			});