Java 5.0 基础 - Enum

最新推荐文章于 2024-07-30 08:45:00 发布

最新推荐文章于 2024-07-30 08:45:00 发布 · 190 阅读

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本文通过一个具体的Java枚举类型的例子展示了如何初始化枚举成员并使用它们。文章中定义了一个枚举Class，每个枚举成员都包含班级名称、学生数量和班主任等属性，并提供了获取这些属性的方法。此外，还演示了如何通过valueOf()方法获取枚举实例以及如何设置和获取枚举成员的特殊属性。

public class EnumeratorTest {

	enum Class{
		ClassA("Class 1", 40, "Bruce"), // Init the constructors by its parameters.
		ClassB("Class 2", 38, "Lee"),
		ClassC("Class 3", 42, "Daniel"),
		ClassD("Class 4", 20, "Anthony");
		
		// Constructor must be set as Private.
		private Class(String className, int students, String classAdvisor){
			_className = className;
			_students = students;
			_classAdvisor = classAdvisor;
		}
		
		String _className;
		int _students;
		String _classAdvisor;
		boolean _isSpecialClass = false;
		
		public String getClassName(){
			return _className;
		}
		
		public int getStudentNum(){
			return _students;
		}
		
		public String getClassAdvisor(){
			return _classAdvisor;
		}
		
		// we can set the attributes
		public void setIsSpecialClass(boolean bol){
			_isSpecialClass = bol;
		}
		
		public boolean getIsSpecialClass(){
			return _isSpecialClass;
		}
	}
	
	@Test
	public void testEnum(){
		Class classA = Class.ClassA;  // get the enum instance by access the attribute
		
		Assert.assertEquals( "Class name equals", "Class 1", classA.getClassName() );
		Assert.assertEquals( "Student num equals", 40, classA.getStudentNum() );
		Assert.assertEquals( "Class advisor name", "Bruce", classA.getClassAdvisor() );
		Assert.assertEquals( "Special class or not", false, classA.getIsSpecialClass() );
		
		Class classD = Class.valueOf("ClassD"); // fetch the enum instance by valueOf().
		classD.setIsSpecialClass( true ); // set it as the special class.
		
		Assert.assertEquals( "Class name equals", "Class 4", classD.getClassName() );
		Assert.assertEquals( "Student num equals", 20, classD.getStudentNum() );
		Assert.assertEquals( "Class advisor name", "Anthony", classD.getClassAdvisor() );
		Assert.assertEquals( "Special class or not", true, classD.getIsSpecialClass() );
		
	}
}

引用: http://www.iteye.com/topic/477731