The enum declaration defines a class (called an enum type). The enum class body can include methods and other fields. The compiler automatically adds some special methods when it creates an enum. For example, they have a static values method that returns an array containing all of the values...
importjava.lang.reflect.Method;enumColor{RED,GREEN,BLUE;}publicclassEnumValuesDynamic{publicstaticvoidmain(String[]args)throwsException{// 步骤一:获取指定枚举类型的Class对象Class<?>enumClass=Color.class;// 步骤二:利用反射获取枚举类型的values方法Methodmethod=enumClass.getMethod("values");// 步骤三:...
publicclassEnumMethodDemo{enumColor{RED,GREEN,BLUE;}enumSize{BIG,MIDDLE,SMALL;}publicstaticvoidmain(String args[]){System.out.println("=== Print all Color ===");for(Color c:Color.values()){System.out.println(c+" ordinal: "+c.ordinal());}System.out.println("=== Print all Size ===...
Interfaces:Base:java.lang.Enum<EnumJavaClass$EnumClass> Methods: [compareTo, equals, getClass, getDeclaringClass, getDescription, hashCode, name, notify, notifyAll, ordinal, toString, valueOf, values, wait] ---Analyzing class java.lang.Enum--- Interfaces:java.lang.Comparable<E>interface java.io....
对此问题的其他引用包括“ Enums.values()方法 ”(Guava线程)和“ Java的Enum.values()隐藏分配 ”(显示缓存Enum.values()返回的数组)。 上面还写了一个JDK错误: JDK-8073381 (“需要API来获取枚举值而不创建新数组”)。 下一篇代码清单中说明了本文中讨论的一些当前可用的变通方法,这是一个简单的Fruit枚举,演...
每个枚举类型都继承自java.lang.Enum,并自动添加了values和valueOf方法。 而每个枚举常量是一个静态常量字段,使用内部类实现,该内部类继承了枚举类。所有枚举常量都通过静态代码块来进行初始化,即在类加载期间就初始化。 另外通过把clone、readObject、writeObject这三个方法定义为final的,同时实现是抛出相应的异常。这样...
publicclassEnumMethodDemo{enumColor{RED,GREEN,BLUE;}enumSize{BIG,MIDDLE,SMALL;}publicstaticvoidmain(String args[]){System.out.println("=== Print all Color ===");for(Color c:Color.values()){System.out.println(c+" ordinal: "+c.ordinal());}System.out.println("=== Print all Size ===...
classT, the implicitly declaredpublic static T valueOf(String)method on that enum may be used instead of this method to map from a name to the corresponding enum constant. All the constants of an enum class can be obtained by calling the implicitpublic static T[] values()method of that ...
()和 valueOf(),稍后会分析它们的用法,到此我们也就明白了,使用关键字enum定义的枚举类型,在编译期后,也将转换成为一个实实在在的类,而在该类中,会存在每个在枚举类型中定义好变量的对应实例对象,如上述的MONDAY枚举类型对应public static final Day MONDAY;,同时编译器会为该类创建两个方法,分别是values()和...
All the constants of an enum class can be obtained by calling the implicit public static T[] values() method of that class. Added in 1.5. Java documentation for java.lang.Enum.valueOf(java.lang.Class<T>, java.lang.String). Portions of this page are modifications based on work created ...