Spring一些小Tips

Bean的申明方式

• 在A中实现FactoryBean接口来完成B的初始化，达到Bean的声明效果

  public class TestA implements InitializingBean, FactoryBean<TestB> {
      @Getter
      @Setter
      private int a;
      private TestB testB;
  
      @Override
      public void afterPropertiesSet() throws Exception {
          this.testB = new TestB();
      }
  
      @Override
      public TestB getObject() throws Exception {
          return this.testB;
      }
  
      @Override
      public Class<?> getObjectType() {
          return (this.testB != null ? this.testB.getClass() : TestB.class);
      }
  
      @Override
      public boolean isSingleton() {
          return true;
      }
  }
  
  @Data
  public class TestB {
      private int b;
  }
  
  @Configuration
  public class BeanConfig {
      @Bean
      public TestA testA() {
          return new TestA();//此时B已经声明好了
      }
  }

• 如何使用@Value初始化类静态属性

  @Component
  public class TestC {
      public static String s;
  
      @Value("${test.s}")
      public void setS(String sVal) {//使用set方法注入，方法需要是非静态的
          s = sVal;
      }
  
      public static String getS() {
          return s;
      }
  }

• properties乱码解决