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## org.apache.cayenne.event
Class EventSubject

    java.lang.Object
      org.apache.cayenne.event.EventSubject

All Implemented Interfaces:
  Serializable

    public class EventSubject

extends Object
implements Serializable

This class encapsulates the String that is used to identify the subject that a listener is interested in. Using plain Strings causes several severe problems:

- it's easy to misspell a subject, leading to undesired behaviour at runtime that is hard to debug.
- in systems with many different subjects there is no safeguard for defining the same subject twice for different purposes. This is especially true in a distributed setting.

See Also:
  Serialized Form

Constructor Summary
`protected` | `EventSubject(String fullSubjectName)` Protected constructor for new subjects.

Method Summary
`boolean` | `equals(Object obj)`
`static EventSubject` | `getSubject(Class<?> subjectOwner, String subjectName)` Returns an event subject identified by the given owner and subject name.
`String` | `getSubjectName()`
`int` | `hashCode()`
`String` | `toString()`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Constructor Detail

### EventSubject

    protected EventSubject(String fullSubjectName)

  Protected constructor for new subjects.

  Parameters:
    `fullSubjectName` - the name of the new subject to be created

Method Detail

### getSubject

    public static EventSubject getSubject(Class<?> subjectOwner,
                                          String subjectName)

  Returns an event subject identified by the given owner and subject name.

  Parameters:
    `subjectOwner` - the Class used for uniquely identifying this subject
    `subjectName` - a String used as name, e.g. "MyEventTopic"
  Throws:
    `IllegalArgumentException` - if subjectOwner/subjectName are `null` or subjectName is empty.

### equals

    public boolean equals(Object obj)

  Overrides:
    `equals` in class `Object`

### hashCode

    public int hashCode()

  Overrides:
    `hashCode` in class `Object`

### getSubjectName

    public String getSubjectName()

### toString

    public String toString()

  Overrides:
    `toString` in class `Object`
  Returns:
    a String in the form `<ClassName 0x123456> SomeName`
  See Also:
    `Object.toString()`

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