Spring 5.0 Cookbook

How to do it...

There are some built-in functional interfaces that Java 1.8 can provide in order to create services depending on the type of transactions needed to be implemented. To illustrate how to use these functional interfaces, follow these steps:

1. Add another method to EmployeeServiceImpl that will retrieve and filter employees with an age greater than 25:

public List<Employee> getEmployeesFunc(){ 
       
     Predicate<Employee> qualifiedEmps =  
         (e) -> e.getAge() > 25;  
     List<Employee> newListEmps = new ArrayList<>(); 
     Iterator<Employee> iterate = 
        employeeDaoImpl.getEmployees().iterator(); 
      while(iterate.hasNext()){ 
        Employee e = iterate.next(); 
        if(qualifiedEmps.test(e)){ 
           newListEmps.add(e); 
        } 
      }   
    return newListEmps; 
} 

Using the Predicate functional ...