org.springframework.core.env

Class PropertySource<T>

  • java.lang.Object
    • org.springframework.core.env.PropertySource<T>
  • Type Parameters:
    T - the source type
    Direct Known Subclasses:
    EnumerablePropertySource, JndiPropertySource, PropertySource.StubPropertySource


    public abstract class PropertySource<T>
    extends java.lang.Object
    Abstract base class representing a source of name/value property pairs. The underlying source object may be of any type T that encapsulates properties. Examples include Properties objects, Map objects, ServletContext and ServletConfig objects (for access to init parameters). Explore the PropertySource type hierarchy to see provided implementations.

    PropertySource objects are not typically used in isolation, but rather through a PropertySources object, which aggregates property sources and in conjunction with a PropertyResolver implementation that can perform precedence-based searches across the set of PropertySources.

    PropertySource identity is determined not based on the content of encapsulated properties, but rather based on the name of the PropertySource alone. This is useful for manipulating PropertySource objects when in collection contexts. See operations in MutablePropertySources as well as the named(String) and toString() methods for details.

    Note that when working with @Configuration classes that the @PropertySource annotation provides a convenient and declarative way of adding property sources to the enclosing Environment.

    Since:
    3.1
    Author:
    Chris Beams
    See Also:
    PropertySources, PropertyResolver, PropertySourcesPropertyResolver, MutablePropertySources, PropertySource
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class and Description
      static class  PropertySource.StubPropertySource
      PropertySource to be used as a placeholder in cases where an actual property source cannot be eagerly initialized at application context creation time.
    • Field Summary

      Fields 
      Modifier and Type Field and Description
      protected Log logger 
      protected java.lang.String name 
      protected T source 
    • Constructor Summary

      Constructors 
      Constructor and Description
      PropertySource(java.lang.String name)
      Create a new PropertySource with the given name and with a new Object instance as the underlying source.
      PropertySource(java.lang.String name, T source)
      Create a new PropertySource with the given name and source object.
    • Method Summary

      All Methods Static Methods Instance Methods Abstract Methods Concrete Methods 
      Modifier and Type Method and Description
      boolean containsProperty(java.lang.String name)
      Return whether this PropertySource contains the given name.
      boolean equals(java.lang.Object other)
      This PropertySource object is equal to the given object if: they are the same instance the name properties for both objects are equal
      java.lang.String getName()
      Return the name of this PropertySource.
      abstract java.lang.Object getProperty(java.lang.String name)
      Return the value associated with the given name, or null if not found.
      T getSource()
      Return the underlying source object for this PropertySource.
      int hashCode()
      Return a hash code derived from the name property of this PropertySource object.
      static PropertySource<?> named(java.lang.String name)
      Return a PropertySource implementation intended for collection comparison purposes only.
      java.lang.String toString()
      Produce concise output (type and name) if the current log level does not include debug.
      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait
    • Field Detail

      • logger

        protected final Log logger
      • name

        protected final java.lang.String name
      • source

        protected final T source
    • Constructor Detail

      • PropertySource

        public PropertySource(java.lang.String name,
                              T source)
        Create a new PropertySource with the given name and source object.
      • PropertySource

        public PropertySource(java.lang.String name)
        Create a new PropertySource with the given name and with a new Object instance as the underlying source.

        Often useful in testing scenarios when creating anonymous implementations that never query an actual source but rather return hard-coded values.

    • Method Detail

      • getName

        public java.lang.String getName()
        Return the name of this PropertySource.
      • getSource

        public T getSource()
        Return the underlying source object for this PropertySource.
      • containsProperty

        public boolean containsProperty(java.lang.String name)
        Return whether this PropertySource contains the given name.

        This implementation simply checks for a null return value from getProperty(String). Subclasses may wish to implement a more efficient algorithm if possible.

        Parameters:
        name - the property name to find
      • equals

        public boolean equals(java.lang.Object other)
        This PropertySource object is equal to the given object if:
        • they are the same instance
        • the name properties for both objects are equal

        No properties other than name are evaluated.

        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Return a hash code derived from the name property of this PropertySource object.
        Overrides:
        hashCode in class java.lang.Object
      • toString

        public java.lang.String toString()
        Produce concise output (type and name) if the current log level does not include debug. If debug is enabled, produce verbose output including the hash code of the PropertySource instance and every name/value property pair.

        This variable verbosity is useful as a property source such as system properties or environment variables may contain an arbitrary number of property pairs, potentially leading to difficult to read exception and log messages.

        Overrides:
        toString in class java.lang.Object
        See Also:
        Log.isDebugEnabled()
      • named

        public static PropertySource<?> named(java.lang.String name)
        Return a PropertySource implementation intended for collection comparison purposes only.

        Primarily for internal use, but given a collection of PropertySource objects, may be used as follows:

         List<PropertySource<?>> sources = new ArrayList<PropertySource<?>>();
         sources.add(new MapPropertySource("sourceA", mapA));
         sources.add(new MapPropertySource("sourceB", mapB));
         assert sources.contains(PropertySource.named("sourceA"));
         assert sources.contains(PropertySource.named("sourceB"));
         assert !sources.contains(PropertySource.named("sourceC"));
         
        The returned PropertySource will throw UnsupportedOperationException if any methods other than equals(Object), hashCode(), and toString() are called.
        Parameters:
        name - the name of the comparison PropertySource to be created and returned.