程序包 org.springframework.boot.autoconfigure.condition

批注接口 ConditionalOnProperty

@Retention(RUNTIME) @Target({TYPE,METHOD}) @Documented @Conditional(org.springframework.boot.autoconfigure.condition.OnPropertyCondition.class) public @interface ConditionalOnProperty
@Conditional that checks if the specified properties have a specific value. By default the properties must be present in the Environment and not equal to false. The havingValue() and matchIfMissing() attributes allow further customizations.

The havingValue() attribute can be used to specify the value that the property should have. The table below shows when a condition matches according to the property value and the havingValue() attribute:

Having values
Property Value havingValue="" havingValue="true" havingValue="false" havingValue="foo"
"true" yes yes no no
"false" no no yes no
"foo" yes no no yes

If the property is not contained in the Environment at all, the matchIfMissing() attribute is consulted. By default missing attributes do not match.

This condition cannot be reliably used for matching collection properties. For example, in the following configuration, the condition matches if spring.example.values is present in the Environment but does not match if spring.example.values[0] is present. 

 @ConditionalOnProperty(prefix = "spring", name = "example.values")
 class ExampleAutoConfiguration {
 }
It is better to use a custom condition for such cases.
从以下版本开始:
1.1.0
作者:
Maciej Walkowiak, Stephane Nicoll, Phillip Webb

  • 可选元素概要

    可选元素
    修饰符和类型
    可选元素
    说明
    String
    havingValue
    The string representation of the expected value for the properties.
    boolean
    matchIfMissing
    Specify if the condition should match if the property is not set.
    String[]
    name
    The name of the properties to test.
    String
    prefix
    A prefix that should be applied to each property.
    String[]
    value
    Alias for name().

  • 元素详细资料

    • value

      String[] value
      Alias for name().
      返回:
      the names
      默认值:
      {}

    • prefix

      String prefix
      A prefix that should be applied to each property. The prefix automatically ends with a dot if not specified. A valid prefix is defined by one or more words separated with dots (e.g. "acme.system.feature").
      返回:
      the prefix
      默认值:
      ""

    • name

      String[] name
      The name of the properties to test. If a prefix has been defined, it is applied to compute the full key of each property. For instance if the prefix is app.config and one value is my-value, the full key would be app.config.my-value

      Use the dashed notation to specify each property, that is all lower case with a "-" to separate words (e.g. my-long-property).

      If multiple names are specified, all of the properties have to pass the test for the condition to match.

      返回:
      the names
      默认值:
      {}

    • havingValue

      String havingValue
      The string representation of the expected value for the properties. If not specified, the property must not be equal to false.
      返回:
      the expected value
      默认值:
      ""

    • matchIfMissing

      boolean matchIfMissing
      Specify if the condition should match if the property is not set. Defaults to false.
      返回:
      if the condition should match if the property is missing
      默认值:
      false