具有多个if else和for语句的重构方法

Question

My method below has code flagged by checkstyle with cyclic complexity = 13 and max allowed is 10:

if (typeOfTable.equals("STRING1")) {
    for (String type1Table : tableType1List) {
        if (fileName.contains(metricTable)) {
            tableType= "STRING1";
            return tableType;
        }
    }
} else if (typeOfTable.equals("STRING2")) {
    for (String type2Table : tableType2List) {
        if (fileName.contains(type2Table)) {
            tableType= "STRING2";
            return tableType;
        }
    }
} else if (typeOfTable.equals("STRING3")) {
    if (fileName.contains("String3")) {
        tableType= "STRING3";
        return tableType;
    }
} else if (typeOfTable.equals("STRING4")) {
    if (fileName.contains("String4")) {
        tableType= "STRING4";
        return tableType;
    }
}

Is the best way to rewrite this with switch statements or split into smaller methods, so it meets the CheckStyle requirement?

Answer 1

I think there are several options and without knowing your class hierarchy using the Strategy Pattern would be a profound way to implement such behavior.

But if you want it quick and dirty you could use an enum and a case statement, eg:

enum TableType {
    STRING1, STRING2, STRING3;

    public static TableType getType(String typeName) {
        for (TableType type : values()) {
            if (type.name().equals(typeName) {
                return type;
            }
        }

        return STRING1; // if you want a default type
    }
}

and the case statement like this:

TableType tableType = TableType.getType(typeOfTable);
switch(tableType) {
    case STRING1:
       ....
       break;
}

And like already recommended in the comments you should use more functions/methods to reduce the amount of copy-paste-code.