ERROR - The method computeIfAbsent(String, Function) in the type Map is not applicable for the arguments (String, String)

Error

The method computeIfAbsent(String, Function<? super String,? extends String>) in the type Map<String,String> is not applicable for the arguments 
 (String, String)

Error Type

Compile Time ( Java 8 )

Sample Code

Map<String,String> intMap = new HashMap<String,String>();
intMap.put("Key1","Value1");
intMap.put("Key2", "Value2");
intMap.computeIfAbsent("Key3", "Value1");
  

Cause

The method computeIfAbsent expects the second argument as the Function and not the String. 

Resolution

Specify the function as the second argument.

intMap.computeIfAbsent("Key3", e->e.concat("ComputedValue"));