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 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:

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    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
    Description
    protected final org.apache.commons.logging.Log
    logger
     
    protected final String
    name
     
    protected final T
    source
     

  • Constructor Summary

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

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    containsProperty(String name)
    Return whether this PropertySource contains the given name.
    boolean
    equals(@Nullable 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
    String
    getName()
    Return the name of this PropertySource.
    abstract @Nullable Object
    getProperty(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(String name)
    Return a PropertySource implementation intended for collection comparison purposes only.
    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 Details

    • logger

      protected final org.apache.commons.logging.Log logger

    • name

      protected final String name

    • source

      protected final T source

  • Constructor Details

    • PropertySource

      public PropertySource(String name, T source)
      Create a new PropertySource with the given name and source object.
      Parameters:
      name - the associated name
      source - the source object

    • PropertySource

      public PropertySource(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 Details

    • getName

      public String getName()
      Return the name of this PropertySource.

      See the class-level Javadoc for details on property source identity and names.

    • getSource

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

    • containsProperty

      public boolean containsProperty(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

    • getProperty

      public abstract @Nullable Object getProperty(String name)
      Return the value associated with the given name, or null if not found.
      Parameters:
      name - the property to find
      See Also:

    • equals

      public boolean equals(@Nullable 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 Object

    • hashCode

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

    • toString

      public 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 difficulties to read exception and log messages.

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

    • named

      public static PropertySource<?> named(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<>();
 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