switch for type string for java 1.6 [duplicate]

Question

I have the following code and I'm wondering if there is a way to use a switch block instead of a bunch of if/else statements. I know that Java supports strings in switch blocks as of Java 1.7 but I'm still working with Java 1.6:

} else if (typeName.equals("Boolean")) {

            return new SwitchInputType<Boolean>(new Boolean((String) memberValue));

        } else if (typeName.equals("Double")) {

            return new SwitchInputType<Double>(new Double((String) memberValue));

        } else if (typeName.equals("Int32"))

Answer 1

You could even make the enum do it for you:

public static void main(String[] args) throws InterruptedException {
    String typeName = "Boolean";
    String memberValue = "memberValue";
    SwitchInputType type = Type.valueOf(typeName).makeType(memberValue);
}

enum Type {
    Boolean {
        SwitchInputType makeType(String memberValue) {
            return new SwitchInputType<Boolean>(new Boolean(memberValue));
        }
    },
    Double {
        SwitchInputType makeType(String memberValue) {
            return new SwitchInputType<Double>(new Double(memberValue));
        }
    }, 
    Int32 {
        SwitchInputType makeType(String memberValue) {
            return new SwitchInputType<Integer>(new Integer(memberValue));
        }
    };

    // All must do this.
    abstract SwitchInputType makeType(String memberValue);
}

static class SwitchInputType<T> {
    public SwitchInputType(Object o) {
    }
}

Answer 2

As your strings are all valid identifiers, you could create an enumeration with those strings as the item labels, use Enum.valueOf(Class, String) (or the similar valueOf(String) method that will be created in your enumeration class) to convert to a member of the enumeration type, and then switch based on that...

Example:

enum TypeName { Boolean, Double, Int32 }

switch (TypeName.valueOf(typeName)) {
   case Boolean: // ...
   case Double: // ...
   case Int32: // ...
}

Answer 3

Ankur has already suggested one way. The other way is define these as constants. Ex - private static final String BOOLEAN = "1";

switch(Integer.parseInt(BOOLEAN)) case 1:...

case 2: ...

and so on.

Answer 4

Map your String to enum, as enums can be used in switch cases. Every Enum has a valueOf(String) method which converts String type to enum type. Then you can match this enum to various cases inside switch. Only thing you need to be careful of is that String should be a valid identifier to be converted to an enum. If the string is not a valid identifier (i.e. cannot be cast to the enum type then you may end up getting IllegalArgumentException.