Bean References

如果评估上下文已使用 Bean 解析器进行配置，则可以使用 @ 符号从表达式中查找 Bean。以下示例展示了如何执行此操作：

If the evaluation context has been configured with a bean resolver, you can look up beans from an expression by using the @ symbol. The following example shows how to do so:

  • Java

  • Kotlin

ExpressionParser parser = new SpelExpressionParser();
StandardEvaluationContext context = new StandardEvaluationContext();
context.setBeanResolver(new MyBeanResolver());

// This will end up calling resolve(context,"something") on MyBeanResolver during evaluation
Object bean = parser.parseExpression("@something").getValue(context);
val parser = SpelExpressionParser()
val context = StandardEvaluationContext()
context.setBeanResolver(MyBeanResolver())

// This will end up calling resolve(context,"something") on MyBeanResolver during evaluation
val bean = parser.parseExpression("@something").getValue(context)

要访问工厂 Bean 本身，应在 Bean 名称前加上 & 符号。以下示例展示了如何执行此操作：

To access a factory bean itself, you should instead prefix the bean name with an & symbol. The following example shows how to do so:

  • Java

  • Kotlin

ExpressionParser parser = new SpelExpressionParser();
StandardEvaluationContext context = new StandardEvaluationContext();
context.setBeanResolver(new MyBeanResolver());

// This will end up calling resolve(context,"&foo") on MyBeanResolver during evaluation
Object bean = parser.parseExpression("&foo").getValue(context);
val parser = SpelExpressionParser()
val context = StandardEvaluationContext()
context.setBeanResolver(MyBeanResolver())

// This will end up calling resolve(context,"&foo") on MyBeanResolver during evaluation
val bean = parser.parseExpression("&foo").getValue(context)