Enums: How to Work With .NET Enum Type

Enums: How to Work With .NET Enum Type

To use .NET enums in your Java project, javonet API provides special NEnum type. Using this class you can keep the reference of particular enum value, get/set the enum value, pass the enum value as method argument or compare enum values.

To initialize reference to .NET enum type you can use the NEnum(String enumTypeName, String enumValue) constructor. As first argument you must provide enum type name with or without namespace. When namespace is not provided Javonet will automatically lookup the enum type in all loaded assemblies, if there is only one type with provided name it will be used. In second argument selected enum value should be provided.

How to initialize NEnum object

Sample enum definition in .NET:

public enum SampleEnum 
{
    ValueOne,
    ValueTwo,
    ValueThree
}

Enum usage in Java:

//Create instance of enum value
NEnum sampleEnumValueOne = new NEnum("SampleEnum","ValueOne");

//Display enum value name
System.out.println(sampleEnumValueOne.getValueName()); //displays "ValueOne"

//Display enum value
System.out.println(sampleEnumValueOne.getValue()); //displays "0"

How to get/set enum value and pass enum as method argument

Sample code in .NET

public enum SampleEnum 
{
    ValueOne,
    ValueTwo,
    ValueThree
}
public class Sample
{
     public SampleEnum EnumField { get; set; }
     public void MethodA(SampleEnum value)
     {
          Console.Out.WriteLine(value);
     }
}

Usage in Java

NObject sampleObj = Javonet.New("Sample");  

//Set enum as property value  
sampleObj.set("EnumField",new NEnum("SampleEnum","ValueTwo"));  

//Get enum from property  
NEnum enumValue = sampleObj.<NEnum>get("EnumField"); 

System.out.println(enumValue.getValueName());
System.out.println(enumValue.getValue()); 

//Pass enum as method argument  
sampleObj.invoke("MethodA",enumValue);  

//Check enum value  
if (enumValue.equals(new NEnum("SampleEnum","ValueTwo")))
{  
	 System.out.println("Enum returned from EnumField equals ValueTwo");  
}  
else  
{  
	 System.out.println("Enum returned from EnumField does not equal to ValueTwo");  
}

See Live Example!