Switch 语句在 Java 7 之前只支持 int和 enum类型。
Java 7 发布后，Switch 语句也支持 String 类。

示例：

public class StringSupportedInSwitch 
{
	public static void main(String[] args)
	{
		System.out.println(getExpendedMessage("one"));
		System.out.println(getExpendedMessage("three"));
		System.out.println(getExpendedMessage("five"));
	}
	static String getExpendedMessage(final String token) 
    {
        String value = null;

        switch (token) 
        {
            case ("one"):
                value = "1";
                break;

            case ("two"):
                value = "2";
                break;

            case ("three"):
                value = "3";
                break;

            default:
                value = "default";
       }

        return value;
    }
}