简介:初次知道枚举 还是刚学java的时候 那时候讲四类八种,还有一种特殊的类型 叫做枚举,开始工作以后发现都是用的常量类Constant 直到现在需要处理数据库的一些东西,那么多类型 长度,如果代码中判断 要写多少if else switch的话要弄多少处理分支。然后同事提示我可以试试枚举。一试,wo CaO,真香
mysql的字段长度枚举类:
public enum MysqlColumnTypeLengthEnum {
BIGINT("bigint", 255), //bigint
BINARY("binary", 255), //binary
BIT("bit", 64), //bit
BLOB("blob", 0), //blob
CHAR("char", 255), //char
DATE("date", 0), //date
DATETIME("datetime", 6), //datetime
DECIMAL("decimal", 65), //decimal
DOUBLE("double", 255), //double
ENUM("enum", 64), //enum
FLOAT("float", 255), //float
GEOMETRY("geometry", 0), //geometry
GEOMETRYCOLLECTION("geometrycollection", 0),//geometrycollection
INT("int", 255), //int
INTEGER("integer", 255), //integer
JSON("json", 0), //json
LINESTRING("linestring", 0), //linestring
LONGBLOB("longblob", 0), //longblob
LONGTEXT("longtext", 0), //longtext
MEDIUMBLOB("mediumblob", 0), //mediumblob
MEDIUMINT("mediumint", 255), //mediumint
MEDIUMTEXT("mediumtext", 0), //mediumtext
MULTILINESTRING("multilinestring", 0), //multilinestring
MULTIPOINT("multipoint", 0), //multipoint
MULTIPOLYGON("multipolygon", 0), //multipolygon
NUMERIC("numeric", 65), //numeric
POINT("point", 0), //point
POLYGON("polygon", 0), //polygon
REAL("real", 255), //real
SET("set", 64), //64
SMALLINT("smallint", 255), //smallint
TEXT("text", 0), //text
TIME("time", 6), //time
TIMESTAMP("timestamp", 6), //timestamp
TINYBLOB("tinyblob", 0), //tinyblob
TINYINT("tinyint", 255), //tinyint
TINYTEXT("tinytext", 0), //tinytext
VARBINARY("varbinary", 65522), //varbinary
VARCHAR("varchar",21840), //varchar
YEAR("year", 4), //year
UNDEFINED_COLUMN("",null); //未定义
public String name;
public Integer len;
MysqlColumnTypeLengthEnum(String name, Integer len){
this.name = name;
this.len = len;
}
public static MysqlColumnTypeLengthEnum getColumnInfo(String name){
for(MysqlColumnTypeLengthEnum item: values()){
if(name.equals(item.name)){
return item;
}
}
return UNDEFINED_COLUMN;
}
}
调用的时候:
List<Map<String, Object>> mysqlTypeList = new ArrayList<>(); for (MysqlColumnTypeLengthEnum item : MysqlColumnTypeLengthEnum.values()) { Map<String, Object> m = new HashMap<>(); m.put("name", item.name); m.put("len", item.len); mysqlTypeList.add(m); }
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