spring中構造方法、@PostConstruct、@Autowired、@Value的加載順序

 探究Spring中 構造方法、@PostConstruct、@Autowired、@Value 的加載順序

@Service
public class TestService {

    public String get () {
        return "hello world";
    }
}

@RestController
public class TestController {

    public TestController () {
        System.err.println("---------------------------------");
        System.err.println("這是構造方法");
        System.err.println("testService = " + testService);
        System.err.println("testUrl = " + testUrl);
        System.err.println("---------------------------------");
    }

    private String testUrl;

    @Value("${emop.config.url}")
    public void setTestUrl (String testUrl) {
        this.testUrl = testUrl;
        System.err.println("---------------------------------");
        System.err.println("這是@Value");
        System.err.println("testService = " + testService);
        System.err.println("testUrl = " + testUrl);
        System.err.println("---------------------------------");
    }

    TestService testService;

    @Autowired
    public void setTestService (TestService testService) {
        this.testService = testService;
        System.err.println("---------------------------------");
        System.err.println("這是@Autowired");
        System.err.println("testService = " + testService);
        System.err.println("testUrl = " + testUrl);
        System.err.println("---------------------------------");
    }

    @PostConstruct
    public void testPostConstructor () {
        System.err.println("---------------------------------");
        System.err.println("這是@PostConstruct方法");
        System.err.println("testService = " + testService);
        System.err.println("testUrl = " + testUrl);
        System.err.println("---------------------------------");
    }

    @GetMapping("/get")
    public String get () {
        return testService.get();
    }
}

從項目啓動的2次輸出結果可以看出，依次打印了：構造方法 》@Autowired/@value 》@PostConstruct，@Autowired和@value的加載應該不分先後