bean运行时值注入

1、Environment

@Configurable
@PropertySource("classpath:/userinfo.properties") //这个属性文件会加载到Spring的Environment中
public class UserInfoConfig {
    @Autowired
    private Environment env;

    @Bean
    public UserInfo userInfo() {
        return new UserInfo(env.getProperty("user.name1"), Integer.parseInt(env.getProperty("user.age")), env.getProperty("user.sex"));
    }
}

2、占位符

@Configurable
public class UserInfoConfig {
    @Value("${user.name1}")
    private String name;
    @Value("${user.age}")
    private Integer age;
    @Value("${user.sex}")
    private String sex;

    @Bean
    public UserInfo userInfo() {
        return new UserInfo(name, age, sex);
    }

/*    @Bean
    public UserInfo userInfo(@Value("${user.name1}") String name, @Value("${user.age}") Integer age, @Value("${user.sex}") String sex) {
        return new UserInfo(name, age, sex);
    }*/

    @Bean
    public static PropertySourcesPlaceholderConfigurer placeholder() {
        PropertySourcesPlaceholderConfigurer placeHolder = new PropertySourcesPlaceholderConfigurer();
        placeHolder.setLocation(new FileSystemResource("D:\05-javadev\test20200609_2\src\main\resources\userinfo.properties"));
        //placeHolder.setLocation(new ClassPathResource("classpath:/userinfo.properties"));
        return placeHolder;
    }
}

3、spel

public class Student {
    @Value("#{userInfo.name}")
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

    @Bean
    public Student student() {
        Student student = new Student();
        return student;
    }