EventSubject (cayenne-doc: Cayenne Documentation 4.2 API)

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

Constructors
Modifier Constructor Description

protected EventSubject(String fullSubjectName)
Protected constructor for new subjects.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`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()