public interface IConstants {
  String MON = "Mon";
  String TUE = "Tue";
  String WED = "Wed";
  String THU = "Thu";
  String FRI = "Fri";
  String SAT = "Sat";
  String SUN = "Sun";
}

package com.hmw.test;
/**
 * 枚举测试类
 * @author <a href="mailto:hemingwang0902@126.com" rel="external nofollow" rel="external nofollow" >何明旺</a>
 */
public enum EnumTest {
  MON, TUE, WED, THU, FRI, SAT, SUN;
}

new Enum<EnumTest>("MON",0);
new Enum<EnumTest>("TUE",1);
new Enum<EnumTest>("WED",2);
  ... ...

public class Test {
  public static void main(String[] args) {
    for (EnumTest e : EnumTest.values()) {
      System.out.println(e.toString());
    }

    System.out.println("----------------我是分隔线------------------");

    EnumTest test = EnumTest.TUE;
    switch (test) {
    case MON:
      System.out.println("今天是星期一");
      break;
    case TUE:
      System.out.println("今天是星期二");
      break;
    // ... ...
    default:
      System.out.println(test);
      break;
    }
  }
}

MON
TUE
WED
THU
FRI
SAT
SUN
----------------我是分隔线------------------
今天是星期二

/**
 * Java学习交流QQ群：589809992 我们一起学Java！
 */
public class Test {
  public static void main(String[] args) {
    EnumTest test = EnumTest.TUE;

    //compareTo(E o)
    switch (test.compareTo(EnumTest.MON)) {
    case -1:
      System.out.println("TUE 在 MON 之前");
      break;
    case 1:
      System.out.println("TUE 在 MON 之后");
      break;
    default:
      System.out.println("TUE 与 MON 在同一位置");
      break;
    }

    //getDeclaringClass()
    System.out.println("getDeclaringClass(): " + test.getDeclaringClass().getName());

    //name() 和 toString()
    System.out.println("name(): " + test.name());
    System.out.println("toString(): " + test.toString());

    //ordinal()， 返回值是从 0 开始
    System.out.println("ordinal(): " + test.ordinal());
  }
}

TUE 在 MON 之后
getDeclaringClass(): com.hmw.test.EnumTest
name(): TUE
toString(): TUE
ordinal(): 1

package com.hmw.test;

/**
 * 枚举测试类
 * 
 * @author <a href="mailto:hemingwang0902@126.com" rel="external nofollow" rel="external nofollow" >何明旺</a>
 */
public enum EnumTest {
  MON(1), TUE(2), WED(3), THU(4), FRI(5), SAT(6) {
    @Override
    public boolean isRest() {
      return true;
    }
  },
  SUN(0) {
    @Override
    public boolean isRest() {
      return true;
    }
  };

  private int value;

  private EnumTest(int value) {
    this.value = value;
  }

  public int getValue() {
    return value;
  }

  public boolean isRest() {
    return false;
  }
}
public class Test {
  public static void main(String[] args) {
    System.out.println("EnumTest.FRI 的 value = " + EnumTest.FRI.getValue());
  }
}

EnumTest.FRI 的 value = 5

/**
 * Java学习交流QQ群：589809992 我们一起学Java！
 */
public class Test {
  public static void main(String[] args) {
    // EnumSet的使用
    EnumSet<EnumTest> weekSet = EnumSet.allOf(EnumTest.class);
    for (EnumTest day : weekSet) {
      System.out.println(day);
    }

    // EnumMap的使用
    EnumMap<EnumTest, String> weekMap = new EnumMap(EnumTest.class);
    weekMap.put(EnumTest.MON, "星期一");
    weekMap.put(EnumTest.TUE, "星期二");
    // ... ...
    for (Iterator<Entry<EnumTest, String>> iter = weekMap.entrySet().iterator(); iter.hasNext();) {
      Entry<EnumTest, String> entry = iter.next();
      System.out.println(entry.getKey().name() + ":" + entry.getValue());
    }
  }
}

public class com.hmw.test.EnumTest extends java.lang.Enum{
  public static final com.hmw.test.EnumTest MON;
  public static final com.hmw.test.EnumTest TUE;
  public static final com.hmw.test.EnumTest WED;
  public static final com.hmw.test.EnumTest THU;
  public static final com.hmw.test.EnumTest FRI;
  public static final com.hmw.test.EnumTest SAT;
  public static final com.hmw.test.EnumTest SUN;
  static {};
  public int getValue();
  public boolean isRest();
  public static com.hmw.test.EnumTest[] values();
  public static com.hmw.test.EnumTest valueOf(java.lang.String);
  com.hmw.test.EnumTest(java.lang.String, int, int, com.hmw.test.EnumTest);
}