Java中枚舉類型Enum的一種使用方式

枚舉類定義如下：

public enum Status {

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

    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，我們在操作數據庫的時候，通常使用數字保存到數據庫中，但是在界面上顯示的時候，需要展示其中文意思，南無我們就可以通過下邊的方式：

public enum FlightType {

    OW(1, "單程"), 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;
    }
}

這樣的話，我們就可以通過getDescByCode方法獲得其對應的中文。

另外，參數的個數是可以進行變化的，例如下邊：

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 {
    
    // 現在（重構后）訂單的來源只有 3 開單這一種
    PAY_RESERVE(1, "支付預約"),
    DIRECT_RESERVE(2, "直接預約"),
    BILL(3, "開單");

    private int value;

    private String name;


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


    /**
     * 按照Value獲得枚舉值
     */
    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;
    }