Java中枚举类型Enum的一种使用方式

枚举类定义如下：

public enum Status {

    SCUUESS("1", "成功"), FAILED("2", "失败");

    private String value;
    private String desc;

    public String getValue() {
        return value;
    }

    public void setValue(String value) {
        this.value = value;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }

    private Status(String value, String desc) {
        this.value = value;
        this.desc = desc;
    }
}

使用方法：

public class StutusTest {
    public static void main(String[] args) {

        System.out.println(Status.SCUUESS.getValue());
        System.out.println(Status.SCUUESS.getDesc());
        System.out.println(Status.FAILED.getValue());
        System.out.println(Status.FAILED.getDesc());
    }
}

再比如，我们在操作数据库的时候，通常使用数字保存到数据库中，但是在界面上显示的时候，需要展示其中文意思，南无我们就可以通过下边的方式：

public enum FlightType {

    OW(1, "单程"), RT(2, "往返");

    public Integer code;
    public String desc;

    FlightType(Integer code, String desc) {
        this.code = code;
        this.desc = desc;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }

    public static FlightType getTypeByCode(Integer code) {
        FlightType defaultType = FlightType.OW;
        for (FlightType ftype : FlightType.values()) {
            if (ftype.code == code) {
                return ftype;
            }
        }
        return defaultType;
    }

    public static String getDescByCode(Integer code) {
        return getTypeByCode(code).desc;
    }
}

这样的话，我们就可以通过getDescByCode方法获得其对应的中文。

另外，参数的个数是可以进行变化的，例如下边：

public enum DatabaseType {
    unknown(null, null, null,null),
    mysql("com.mysql.jdbc.Driver", "com.mysql.jdbc.jdbc2.optional.MysqlXADataSource", "select 1",Dialect.MYSQL),
    h2("org.h2.Driver", "org.h2.jdbcx.JdbcDataSource", "select 1",Dialect.H2),
    oracle("oracle.jdbc.driver.OracleDriver", "oracle.jdbc.xa.client.OracleXADataSource", "select 1 from dual",Dialect.ORACLE);

    DatabaseType(String driverClassName, String xaDataSourceClassName, String testQuery,Dialect dialect) {
        this.driverClassName = driverClassName;
        this.testQuery = testQuery;
        this.xaDataSourceClassName = xaDataSourceClassName;
        this.dialect=dialect;
    }

    private final String testQuery;

    private final String driverClassName;

    private final String xaDataSourceClassName;
    private final Dialect dialect;
    public String getDriverClassName() {
        return driverClassName;
    }

    public String getXaDataSourceClassName() {
        return xaDataSourceClassName;
    }

    public String getTestQuery() {
        return testQuery;
    }

    public Dialect getDialect() {
        return dialect;
    }

    public static DatabaseType fromJdbcUrl(String url) {
        if (StringUtils.hasLength(url)) {
            Assert.isTrue(url.startsWith("jdbc"), "URL must start with 'jdbc'");
            String urlWithoutPrefix = url.substring("jdbc".length()).toLowerCase();

            for (DatabaseType driver : values()) {
                String prefix = ":" + driver.name().toLowerCase() + ":";
                if (driver != unknown && urlWithoutPrefix.startsWith(prefix)) {
                    return driver;
                }
            }
        }
        return unknown;
    }
}

public enum OrderFromSourceEnum implements EnumValue {
    
    // 现在（重构后）订单的来源只有 3 开单这一种
    PAY_RESERVE(1, "支付预约"),
    DIRECT_RESERVE(2, "直接预约"),
    BILL(3, "开单");

    private int value;

    private String name;


    OrderFromSourceEnum(Integer value, String name) {
        this.value = value;
        this.name = name;
    }


    /**
     * 按照Value获得枚举值
     */
    public static OrderFromSourceEnum valueOf(Integer value) {
        if (value != null) {
            for (OrderFromSourceEnum fsEnum : OrderFromSourceEnum.values()) {
                if (fsEnum.getValue() == value) {
                    return fsEnum;
                }
            }
        }
        return null;
    }


    @Override
    public int getValue() {
        return value;
    }


    @Override
    public String getName() {
        return name;
    }