Java – Convert String To Enum Object

Review below Java enum example, how to convert a String like ‘arin’ to WhoisRIR.ARIN Enum object?

1. Problem

WhoisRIR rir = //convert 'arin' to enum WhoisRIR.ARIN ?

WhoisRIR.java

package com.mkyong.whois.utils; public enum WhoisRIR { ARIN("whois.arin.net"), RIPE("whois.ripe.net"), APNIC("whois.apnic.net"), AFRINIC("whois.afrinic.net"), LACNIC("whois.lacnic.net"),JPNIC("whois.nic.ad.jp"),KRNIC("whois.nic.or.kr"),CNNIC("ipwhois.cnnic.cn"), //should query apnicUNKNOWN(""); private String url; private WhoisRIR(String url) {this.url = url;} public String getUrl() {return url;} }

2. Solution

To solve it, use enum valueOf() and convert the String to uppercase and set a default locale.

TestEnum.java

package com.mkyong.whois.utils; import java.util.Locale; public class TestEnum { public static void main(String[] args) { //Solution : Uses valueOf()System.out.println(WhoisRIR.valueOf("arin".toUpperCase())); //Recommended Solution : add localeWhoisRIR rir = WhoisRIR.valueOf("ripe".toUpperCase(Locale.ENGLISH));System.out.println(rir);System.out.println(rir.getUrl()); } }

Output

ARINRIPEwhois.ripe.net

Test it again, without convert to uppercase :

TestEnum.java

package com.mkyong.whois.utils; import java.util.Locale; public class TestEnum { public static void main(String[] args) { //error, need convert the String to uppercaseSystem.out.println(WhoisRIR.valueOf("arin")); } }

Output

Exception in thread "main" java.lang.IllegalArgumentException:                     No enum constant com.mkyong.whois.utils.WhoisRIR.arin at java.lang.Enum.valueOf(Unknown Source)at com.mkyong.whois.utils.WhoisRIR.valueOf(WhoisRIR.java:1)at com.mkyong.whois.utils.TestEnum.main(TestEnum.java:17)

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