How to convert string value into Enum in Java?

Question

In my Java Program have Enum class like..

public enum DemoType{ DAILY, WEEKLY, MONTHLY;  } 

And in my jsp i'm taking values from user like select box and this Jsp called like DemoJspBean ..

<form:select path="repeatWeektype">     <form:option value="DAILY" />     <form:option value="WEEKLY" />     <form:option value="MONTHLY" /> </form:select> 

My HibernateVO class is ..

public class DemoVO{   @Column(name = "REPEAT_TYPE")   @Enumerated(EnumType.STRING)   private RepeatType repeatType; } 

Now i want to insert this value into DB using Hibernate Bean(setter and getter)

DemoVO demo = new DemoVO(); demo.setRepeatType(demoJspBean.getRepeatWeektype()); 

but it is show error..

So how to convert my String value into enum class type?

Answer 1

Use the valueOf method on the Enum class.

DemoType demoType =   DemoType.valueOf("DAILY") 

It'll throw an IllegalArgumentException should the string argument provided be invalid. Using your example

DemoType demoType =  DemoType.valueOf("HOURLY"); 

The line above will throw an IllegalArgumentException because HOURLY is not part of your DemoType

Answer 2

This may help you to understand how enum types work.

Say, This is my enum class.

public enum GetDate {  SUNDAY("1"), MONDAY("2"), TUESDAY("3"), WEDNESDAY("4"), THURSDAY("5"), FRIDAY("6"), SATURDAY("7"); private String code;  private GetDate(String code) {     this.code = code; }  public String getCode() {     return code; }  public static GetDate getEnum(String code) {      switch (code) {         case "1":             return SUNDAY;         case "2":             return MONDAY;         case "3":             return TUESDAY;         case "4":             return WEDNESDAY;         case "5":             return THURSDAY;         case "6":             return FRIDAY;         case "7":             return SATURDAY;         default:             return null;      }    }  } 

Following shows how my enum works

public class MyClass { public static void main(String[] args) {     System.out.println("Sunday enum value " + GetDate.SUNDAY);  // enum SUNDAY     System.out.println("Name of the day assign to 1 " + GetDate.getEnum("1"));  // enum SUNDAY     System.out.println("Sunday enum value " + GetDate.valueOf("SUNDAY").getCode()); // String code of SUNDAY     System.out.println("Sunday enum value " + GetDate.valueOf("SUNDAY"));// enum Sunday    } }