There are few ways to create Java stream objects from a typical collection or array data store. To use the Stream API, do the following steps:

1. Let us create an experimental service class, EmployeeStreamService, which consists of service methods dedicated to stream methods. This first method only shows how to extract streams from employeeDaoImpl:

@Service("employeeStreamService") 
public class EmployeeStreamService { 
   
  @Autowired 
  private EmployeeDao employeeDaoImpl; 
   
  public void getCollectionStreams(){ 
    Stream<Employee> serial = 
        employeeDaoImpl.getEmployees().stream(); 
    Stream<Employee> parallel = 
        employeeDaoImpl.getEmployees().parallelStream(); 
  } 
}

2. Next, add another method that illustrates how to extract stream data from an existing List<String> or Set<String> collection:

public void getListData(){ 
      List<String> employeeIDS = 
          Arrays.asList("23234", "353453", "22222",  
             "5555", "676767"); 
      Stream<String> streamsIds = employeeIDS.stream(); 
      Set<String> candidates = new HashSet<String>(); 
      candidates.add("Joel"); 
      candidates.add("Candy"); 
      candidates.add("Sherwin"); 
      Stream<String> streamCandidates =  
          candidates.stream(); 
  } 

3. Lastly, the method below will show us how to extract a stream from an array of long, int, and double data:

public void getArrayData(){ 
      int[] ages = {24, 33, 21, 22, 45}; 
      IntStream ageStream = Arrays.stream(ages); 
       
      double[] salaries = {33000.50, 23100.20, 45000.50}; 
      DoubleStream salStream = Arrays.stream(salaries); 
       
      long[] longDates = {23434432342L, 11123343435L,  
         34343342343L}; 
      LongStream dateStream = Arrays.stream(longDates); 
} 

4. Save all files.