动态配置

动态配置简单说明

替代本地项目application.properties或者application.yml

• 定义开关

/**
 * 
 * @author hejian
 *
 */
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Import(TestPropertyPlaceholderConfigurer.class)
public @interface EnableDisConfig {

}

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2.PropertySourcesPlaceholderConfigurer
提供配置解析功能,模拟远程拉取配置

/**
 * 
 * @author hejian
 *
 */
public class TestPropertyPlaceholderConfigurer extends PropertySourcesPlaceholderConfigurer implements Ordered  {
    
    @Override
    protected void loadProperties(Properties props) throws IOException {
        // 远程配置中心拉取当前应用的所有配置项，构建成Properties对象，委托spring进行解析占位符${""}
        props.put("name", "test");
        System.out.println("in success");
        super.setLocalOverride(true);
        super.loadProperties(props);
    }
    
    @Override
    public int getOrder() {
        return -1;
    }
}

• 热更新
  动态通知应用变更k-v,获取spring容器对象，处理@value注解，重新赋值

        /**
         * 动态通知应用变更k-v,获取spring容器对象，处理@value注解，重新赋值
         */
        String[] beans = applicationContext.getBeanDefinitionNames();
        Assert.noNullElements(beans,"无实例化bean对象");
        for (String beanName : beans) {
            Class<?> bean = applicationContext.getType(beanName);
            
            ReflectionUtils.doWithFields(bean, new FieldCallback() {

                @Override
                public void doWith(Field field) throws IllegalArgumentException, IllegalAccessException {
                    System.out.println("BeanName:" + beanName);
                    System.out.println("Bean的类型：" + bean);
                    System.out.println("Bean所在的包：" + bean.getPackage());
                    System.out.println(">>>>>>>" + field.getName());
                    ReflectionUtils.makeAccessible(field);
                    ReflectionUtils.setField(field, applicationContext.getBean(beanName), value);
                }
            }, new FieldFilter() {
                @Override
                public boolean matches(Field field) {
                    return field.isAnnotationPresent(Value.class) && key.equals(StringResolver.getValue(field.getAnnotation(Value.class).value()));
                }
            });
        }
    }

• 测试结果
  OK

/**
 * 
 * @author hejian
 *
 */
@Component
public class TestManage {
    
   @Autowired
    private Environment env;
    
    @Value("${name}")
    private String name; 
    
    
    @PostConstruct
    public String getName() {
        System.out.println(env.getProperty("test.msg"));
        System.out.println(env.getProperty("server.port"));
        return name;
    }
}

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