Given the following java enum:
public enum AgeRange {
A18TO23 {
public String toString() {
return "18 - 23";
}
},
A24TO29 {
public String toString() {
return "24 - 29";
}
},
A30TO35 {
public String toString() {
return "30 - 35";
}
},
}
Is there any way to convert a string value of "18 - 23" to the...
An Enum in Java implements the Comparable interface. It would have been nice to override Comparable's compareTo method, but here it's marked as final. The default natural order on Enum's compareTo is the listed order. Does anyone know why a Java Enum has this restriction?
Today I was browsing through some question on this site and I found mention of enum being used in singleton pattern and that there are some thread safety benefits to such solution.
I never used enums and I have been programing in java for more than couple a years now. And apparently they changed a lot and now they even do full blown support of OOP within them selfs.
Now why and what for shoul...
Perhap this is a simple basic question
Having an enum
public enum TK{
ID,GROUP,DATA,FAIL;
}
Can I get the order number for example ID=0, GROUP=2, DATA=3, FAIL=4 ?
This is a way to to that, but a weird and long one! =S
public enum TK{
ID(0),GROUP(1),DATA(2),FAIL(3);
int num;
TK(int n)
{
this.num=n;
}
public int g...
Is there a way to check if an enum value is 'greater/equal' to another value?
I want to check if an error level is 'error or above'.
Given the followin enum :
public enum Car
{
NANO ("Very Cheap", "India"),
MERCEDES ("Expensive", "Germany"),
FERRARI ("Very Expensive", "Italy");
public final String cost;
public final String madeIn;
Car(String cost, String madeIn)
{
this.cost= cost;
this.madeIn= madeIn;
}
}
Does someone know a...
While using Java's switch case, it excepts only char and int, but I want to provide string cases. How to make this possible?
When working with variables/parameters that can only take a finite number of values, I try to always use Java's enum, as in
public enum BonusType {
MONTHLY, YEARLY, ONE_OFF
}
As long as I stay inside my code, that works fine. However, I often need to interface with other code that uses plain int (or String) values for the same purpose, or I need to read/write from/to a database where the ...
If a Java class implements the Serializable interface but does not have a public clone() method, it is usually possible to create a deep copy like this:
class CloneHelper {
@SuppressWarnings("unchecked")
public static <T extends Serializable> T clone(T obj) {
try {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = n...
I have a problem in Java using Enums.
I have read the documentation about assigning value parameters to Enums.
But, my question is what about multiple values, is it possible?
This what I would like to achieve:
I have an Enum for languages. Each language is represented by its name and some shorter aliases (not always, and not always the same number of aliases)
Here is an example:
public enum ...
Consider this code:
public interface Foo extends Comparable<Foo> { ... }
public enum FooImpl implements Foo { ... }
Due to the restrictions of type erasure, I receive the following error:
java.lang.Comparable cannot be inherited with different arguments: <Foo> and <FooImpl>
I have the following requirements:
FooImpl needs to be an enum, because I need to use it as a d...
In Java, I'd like to be able to define marker interfaces, that forced implementations to provide static methods. For example, for simple text-serialization/deserialization I'd like to be able to define an interface that looked something like this:
public interface TextTransformable<T>{
public static T fromText(String text);
public String toText();
Since interfaces in Java can't c...
While reading Effective Java I came across the suggestion to "use enums instead of int constants". In a current project I am doing something similar to that below:
int COL_NAME = 0;
int COL_SURNAME = 1;
table[COL_NAME] = "JONES"
How would I use enums instead to acheive this? Due to the interface I'm forced to use, I must use an int for my index. The example above is just an example. I'm ac...
I seem to have faced this problem many times and I wanted to ask the community whether I am just barking up the wrong tree. Basically my question can be distilled down to this: if I have an enum (in Java) for which the values are important, should I be using an enum at all or is there a better way, and if I do use an enum then what is the best way to reverse the lookup?
Here's an example. Supp...
I've noticed that the following snippet...
@Override
public boolean equals(Object otherObject) {
...
}
...is not allowed for an Enum, since the method equals(Object x) is defined as final in Enum. Why is this so?
I cannot think of any use case which would require overriding equals(Object) for Enum. I'm just curious to know the reasoning behind this behavior.
If I have a string like:
String myColor = "Color.RED";
How do I get that to work in:
graphics.setColor(myColor);
I guess I'm asking how do I pass a variable object name to a function. I've tried a bunch of stuff and can not get it working.
Every Java enumeration has a static values() method can be used like this
for (MyEnum enum : MyEnum.values()) {
// Do something with enum
}
However, I cannot figure out where this method is defined. There's no mention of it in the Javadoc and it doesn't appear anywhere in the source file.
I'd like to create a generic enum-based mapper for IBatis. I'm doing this with the below code. This does have compile time errors, which I don't know how to fix. Maybe my solution is just plain wrong (keep in mind the use of IBatis), in such case please suggest something better.
Any help appreciated.
What I want to achieve is to define subsequent mappers as:
public class XEnumTypeHandler ext...
I'm currently creating integer constants in the following manner.
public class Constants {
public static int SIGN_CREATE=0;
public static int SIGN_CREATE=1;
public static int HOME_SCREEN=2;
public static int REGISTER_SCREEN=3;
}
When i try to do this in enum manner
public enum PAGE{SIGN_CREATE,SIGN_CREATE,HOME_SCREEN,REGISTER_SCREEN}
and When i used PAGE.SIGN_CREATE it should return 1;
The ordinal() method can get the ordinal of a enum instance. How can I set the ordinal for a enum ?
I have the following enum:
public enum Status implements StringEnum{
ONLINE("on"),OFFLINE("off");
private String status = null;
private Status(String status) {
this.status = status;
}
public String toString() {
return this.status;
}
public static Status find(String value) {
for(Status status : Status.values()) {
if(status.toString().equals(value)) {
return status;
...
