Package org.apache.tapestry5.ioc.internal.services

## Class SystemPropertiesSymbolProvider

- java.lang.Object
- - org.apache.tapestry5.ioc.internal.services.SystemPropertiesSymbolProvider

- All Implemented Interfaces:
    `SymbolProvider`

      public class SystemPropertiesSymbolProvider
      extends Object
      implements SymbolProvider

  Obtains symbol values from JVM System properties. This implementation is usually ordered first, so that explicit overrides, provided as JVM system properties, can take effect.

- - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `SystemPropertiesSymbolProvider()` |

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `String` | `valueForSymbol​(String symbolName)` | Returns the value for the symbol, or null if this provider can not provide a value.

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### SystemPropertiesSymbolProvider

          public SystemPropertiesSymbolProvider()

  - ### Method Detail

    - #### valueForSymbol

          public String valueForSymbol​(String symbolName)

      Description copied from interface: `SymbolProvider`
      Returns the value for the symbol, or null if this provider can not provide a value. The value itself may contain symbols that will be recursively expanded.
      Specified by:
        `valueForSymbol` in interface `SymbolProvider`
      Returns:
        the value or null