Question

bean定义如下：

import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.web.client.RestTemplate;

import com.ma2oo.model.domain.User;
import com.ma2oo.model.res.interfaces.IUserService;

@Configuration
@PropertySource("classpath:exam-binary.properties")
public class UserServiceImpl implements IUserService {
    private static final RestTemplate restTemplate = new RestTemplate();

    @Value("${user.post.uri}")
    private String registerUri;

    public User register(final User user) {
        System.out.println(registerUri.toString());
        return restTemplate.postForObject(registerUri, user, User.class);
    }

    @Bean(name = "userServiceImpl")
    public IUserService getUserService() {
        return new UserServiceImpl();
    }
}

导入的属性文件位于src/main/resources下。变量就像：

user.post.uri=http://localhost:9000/users/newUser

用于调用此函数的方法如下：

ApplicationContext applicationContext = new AnnotationConfigApplicationContext(UserServiceImpl.class);
IUserService userService = (UserServiceImpl) applicationContext.getBean("userServiceImpl");
User result = userService.register(register);

函数register()的标准输出是${user.post.uri}，这意味着该值不会自动装配。例外描述是：

java.lang.IllegalArgumentException: Not enough variable values available to expand 'user.post.uri'

有人可以帮忙吗？提前谢谢。

Answer 1

尝试在配置中添加propertySourcesPlaceholderConfigurer，

   @Bean
   public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
      return new PropertySourcesPlaceholderConfigurer();
   }

@PropertySource注释不会自动向Spring注册PropertySourcesPlaceholderConfigurer。相反，必须在配置中显式定义bean才能使属性解析机制正常工作。[reference]

在spring docs.

中详细了解相关信息

@Value无法从属性自动装配

1 个答案: