详解Spring Boot的GenericApplicationContext使用教程

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
      http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.zetcode</groupId>
  <artifactId>genappctx</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>genappctx</name>
  <description>Using GenericApplicationContext</description>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.0.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>11</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

spring.main.banner-mode = off 
logging.level.root = ERROR 
logging.pattern.console =％d {dd-MM-yyyy HH：mm：ss}％magenta（[％thread]）％highlight（％ - 5level） ）％logger。％M - ％msg％n

public class TimeService {

  public Instant getNow() {

    return Instant.now();
  }
}

@SpringBootApplication
public class MyApplication implements CommandLineRunner {

  @Autowired
  private GenericApplicationContext context;

  public static void main(String[] args) {

    SpringApplication.run(MyApplication.class, args);
  }

  @Override
  public void run(String... args) throws Exception {

    context.registerBean("com.zetcode.Service.TimeService",
        TimeService.class, () -> new TimeService());

    var timeService = (TimeService) context.getBean(TimeService.class);

    System.out.println(timeService.getNow());

    context.registerShutdownHook();
  }
}

@RunWith(SpringRunner.class)
@SpringBootTest
public class MyApplicationTests {

  @Autowired
  private GenericApplicationContext context;

  @Test
  public void testNow() {

    var timeService = (TimeService) context.getBean("com.zetcode.Service.TimeService");
    var now = timeService.getNow();

    assertThat(now.isBefore(Instant.now()));
  }
}