Will calling an enum with an object reference as a value create an object every time it's called?
This became my concern mainly because of this:
public enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
The Host class is Spring @ConfigurationProperties annotated to be injected with values from an application.properties file at runtime. If I write that as a value of an enum, will it create a new object instance of Host every time I use Method.POST?
java enums
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
add a comment |
This became my concern mainly because of this:
public enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
The Host class is Spring @ConfigurationProperties annotated to be injected with values from an application.properties file at runtime. If I write that as a value of an enum, will it create a new object instance of Host every time I use Method.POST?
java enums
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
1
Shouldn't, theoretically.POSTshould be a singleton. And that should be easy to test (just add a line of logging to the constructor)
– ernest_k
Nov 22 '18 at 7:10
add a comment |
This became my concern mainly because of this:
public enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
The Host class is Spring @ConfigurationProperties annotated to be injected with values from an application.properties file at runtime. If I write that as a value of an enum, will it create a new object instance of Host every time I use Method.POST?
java enums
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
This became my concern mainly because of this:
public enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
The Host class is Spring @ConfigurationProperties annotated to be injected with values from an application.properties file at runtime. If I write that as a value of an enum, will it create a new object instance of Host every time I use Method.POST?
java enums
java enums
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
asked Nov 22 '18 at 7:02
Rigo SarmientoRigo Sarmiento
14510
14510
1
Shouldn't, theoretically.POSTshould be a singleton. And that should be easy to test (just add a line of logging to the constructor)
– ernest_k
Nov 22 '18 at 7:10
add a comment |
1
Shouldn't, theoretically.POSTshould be a singleton. And that should be easy to test (just add a line of logging to the constructor)
– ernest_k
Nov 22 '18 at 7:10
1
1
Shouldn't, theoretically.
POST should be a singleton. And that should be easy to test (just add a line of logging to the constructor)– ernest_k
Nov 22 '18 at 7:10
Shouldn't, theoretically.
POST should be a singleton. And that should be easy to test (just add a line of logging to the constructor)– ernest_k
Nov 22 '18 at 7:10
add a comment |
2 Answers
2
active
oldest
votes
No, It will create instance only once. This can be checked with a print statement like below. Here getAssets() and constructor has been called only once:
public class Host {
public static void main(String args) {
System.out.println("Hello World!");
System.out.println(Method.POST);
System.out.println(Method.POST);
System.out.println(Method.POST);
}
Host()
{
System.out.println("--------------");
}
String getAssets()
{
System.out.println("ssssssssssss");
return "eeee";
}
}
enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
O/P:
Hello World!
--------------
ssssssssssss
POST
POST
POST
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
add a comment |
All values of an Enumerator are singletons, which means, they are initialized once and reused every time you access it. So you can see the "definition" of an Enumerator Value as 'Constructor'.
This also means: if you provide a setter for the property "method" and change its value at runtime, the next access will return the new value! singleton does not mean its value is final.
public enum Method {
POST(new Host().getAssets()), // definition
GET("GET"),// definition
DELETE("DELETE"),// definition
PUT("PUT");// definition
private String method;
// Constructor
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
answered Nov 22 '18 at 7:24
lumolumo
343313
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
No, It will create instance only once. This can be checked with a print statement like below. Here getAssets() and constructor has been called only once:
public class Host {
public static void main(String args) {
System.out.println("Hello World!");
System.out.println(Method.POST);
System.out.println(Method.POST);
System.out.println(Method.POST);
}
Host()
{
System.out.println("--------------");
}
String getAssets()
{
System.out.println("ssssssssssss");
return "eeee";
}
}
enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
O/P:
Hello World!
--------------
ssssssssssss
POST
POST
POST
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
add a comment |
No, It will create instance only once. This can be checked with a print statement like below. Here getAssets() and constructor has been called only once:
public class Host {
public static void main(String args) {
System.out.println("Hello World!");
System.out.println(Method.POST);
System.out.println(Method.POST);
System.out.println(Method.POST);
}
Host()
{
System.out.println("--------------");
}
String getAssets()
{
System.out.println("ssssssssssss");
return "eeee";
}
}
enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
O/P:
Hello World!
--------------
ssssssssssss
POST
POST
POST
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
add a comment |
No, It will create instance only once. This can be checked with a print statement like below. Here getAssets() and constructor has been called only once:
public class Host {
public static void main(String args) {
System.out.println("Hello World!");
System.out.println(Method.POST);
System.out.println(Method.POST);
System.out.println(Method.POST);
}
Host()
{
System.out.println("--------------");
}
String getAssets()
{
System.out.println("ssssssssssss");
return "eeee";
}
}
enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
O/P:
Hello World!
--------------
ssssssssssss
POST
POST
POST
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
No, It will create instance only once. This can be checked with a print statement like below. Here getAssets() and constructor has been called only once:
public class Host {
public static void main(String args) {
System.out.println("Hello World!");
System.out.println(Method.POST);
System.out.println(Method.POST);
System.out.println(Method.POST);
}
Host()
{
System.out.println("--------------");
}
String getAssets()
{
System.out.println("ssssssssssss");
return "eeee";
}
}
enum Method {
POST(new Host().getAssets()),
GET("GET"),
DELETE("DELETE"),
PUT("PUT");
private String method;
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
O/P:
Hello World!
--------------
ssssssssssss
POST
POST
POST
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
answered Nov 22 '18 at 7:16
Shubhendu PramanikShubhendu Pramanik
2,4402719
2,4402719
add a comment |
add a comment |
All values of an Enumerator are singletons, which means, they are initialized once and reused every time you access it. So you can see the "definition" of an Enumerator Value as 'Constructor'.
This also means: if you provide a setter for the property "method" and change its value at runtime, the next access will return the new value! singleton does not mean its value is final.
public enum Method {
POST(new Host().getAssets()), // definition
GET("GET"),// definition
DELETE("DELETE"),// definition
PUT("PUT");// definition
private String method;
// Constructor
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
answered Nov 22 '18 at 7:24
lumolumo
343313
add a comment |
All values of an Enumerator are singletons, which means, they are initialized once and reused every time you access it. So you can see the "definition" of an Enumerator Value as 'Constructor'.
This also means: if you provide a setter for the property "method" and change its value at runtime, the next access will return the new value! singleton does not mean its value is final.
public enum Method {
POST(new Host().getAssets()), // definition
GET("GET"),// definition
DELETE("DELETE"),// definition
PUT("PUT");// definition
private String method;
// Constructor
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
answered Nov 22 '18 at 7:24
lumolumo
343313
add a comment |
All values of an Enumerator are singletons, which means, they are initialized once and reused every time you access it. So you can see the "definition" of an Enumerator Value as 'Constructor'.
This also means: if you provide a setter for the property "method" and change its value at runtime, the next access will return the new value! singleton does not mean its value is final.
public enum Method {
POST(new Host().getAssets()), // definition
GET("GET"),// definition
DELETE("DELETE"),// definition
PUT("PUT");// definition
private String method;
// Constructor
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
answered Nov 22 '18 at 7:24
lumolumo
343313
All values of an Enumerator are singletons, which means, they are initialized once and reused every time you access it. So you can see the "definition" of an Enumerator Value as 'Constructor'.
This also means: if you provide a setter for the property "method" and change its value at runtime, the next access will return the new value! singleton does not mean its value is final.
public enum Method {
POST(new Host().getAssets()), // definition
GET("GET"),// definition
DELETE("DELETE"),// definition
PUT("PUT");// definition
private String method;
// Constructor
Method(String s) {
method = s;
}
private String getMethod() {
return method;
}
}
answered Nov 22 '18 at 7:24
lumolumo
343313
answered Nov 22 '18 at 7:24
lumolumo
343313
answered Nov 22 '18 at 7:24
lumolumo
343313
answered Nov 22 '18 at 7:24
lumolumo
343313
343313
add a comment |
add a comment |
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1
Shouldn't, theoretically.
POSTshould be a singleton. And that should be easy to test (just add a line of logging to the constructor)– ernest_k
Nov 22 '18 at 7:10