枚举类

/**
 *  枚举类.
 */
public class Main {
    public static void main(String[] args) {
        System.out.println(CompanyEnum.SF.getCode());
        System.out.println(CompanyEnum.SF.getCompany());
        System.out.println(CompanyEnum.getCodeByCompany("顺丰速运"));
    }
}

//被枚举的成员默认是 public static final 修饰 
 enum CompanyEnum {
    SF("顺丰速运",1001),YTO("圆通速递", 1002),STO("申通物流",1003),YD("韵达快运",1004),YZPY("中国邮政",1005);

     //利用构造函数将变量赋值，然后通过get方法获取指定值
    private CompanyEnum(String company, int code) {
        this.company = company;
        this.code = code;
    }

    private String company; // 公司名称
    private int code; // 公司编码
    public String getCompany() {
        return company;
    }
    public void setCompany(String company) {
        this.company = company;
    }
    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }

    //根据物流公司名字获取对应的编码
    public static int getCodeByCompany(String company) {
        for (CompanyEnum c : CompanyEnum.values()) { //遍历枚举类 
            if (c.getCompany().equals(company.trim())) {
                return c.code;
            }
        }
        return 0;
    }
    //根据物流公司编码获取对应的名字
    public static String getCompanyByCode(int code) {
        for (CompanyEnum c : CompanyEnum.values()) {
            if (c.getCode() == code) {
                return c.getCompany();
            }
        }
        return null;
    }
}