测试性能：package com.sandbox.test;import lombok.Getter;import org.springframework.beans.factory.annotation.Value;import org.springframework.context.annotation.PropertySource;import org.springframework.stereotype.Component;@Component@PropertySource("classpath:new-test.properties")public class TestProperties {    @Getter    @Value("${homepage.url}")    private String homePageUrl;}配置：package com.sandbox.test;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;@Configuration@ComponentScan(basePackages = {"com.sandbox"})public class SpringContext {}new-test.properties位于 /src/test/resources 中的文件内容：homepage.url=https://tst.mysite.com课堂上进行了两次测试MyTest，第一个 - 不起作用，第二个 - 工作正常：package com.sandbox.test;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.context.annotation.AnnotationConfigApplicationContext;import org.springframework.test.context.ContextConfiguration;import org.testng.Assert;import org.testng.annotations.Test;@ContextConfiguration(classes = {SpringContext.class})public class MyTest {    @Autowired    private TestProperties testProperties;    @Test    public void thisDoesntWork() {        Assert.assertNotNull(testProperties);        System.out.println(testProperties.getHomePageUrl());    }    @Test    public void thisWorks() {        AnnotationConfigApplicationContext appContext = new AnnotationConfigApplicationContext(SpringContext.class);        TestProperties testProps = appContext.getBean(TestProperties.class);        Assert.assertNotNull(testProps);        System.out.println(testProps.getHomePageUrl());    }}目标是在不使用 xml 的情况下自动装配类testProperties中的字段。但目前是. 注释已经到位，但我缺少什么？...MyTestnull@Component@ComponentScan