Java 8 Optional: using map + null return value is allowed, no need to do flatMap + ofNullable. http://calavera.info/v3/blog/2016/11/17/nic.html

optional.java

  @Test
  public void testOptional() {
    assertEquals(Optional.of(
        new AClass())
        .map(AClass::getSomeObject)
        .map(BClass::getSomeText)
        .map(String::trim)
        .orElse(""), "");
    assertEquals(Optional.of(
        new AClass(new BClass()))
        .map(AClass::getSomeObject)
        .map(BClass::getSomeText)
        .map(String::trim)
        .orElse(""), "");
    assertEquals(Optional.of(
        new AClass(new BClass("  test  ")))
        .map(AClass::getSomeObject)
        .map(BClass::getSomeText)
        .map(String::trim)
        .orElse(""), "test");

    assertEquals(Optional.of(
        new AClass())
        .flatMap(aClass -> Optional.ofNullable(aClass.getSomeObject()))
        .flatMap(bClass -> Optional.ofNullable(bClass.getSomeText()))
        .map(String::trim)
        .orElse(""), "");
    assertEquals(Optional.of(
        new AClass(new BClass()))
        .flatMap(aClass -> Optional.ofNullable(aClass.getSomeObject()))
        .flatMap(bClass -> Optional.ofNullable(bClass.getSomeText()))
        .map(String::trim)
        .orElse(""), "");
    assertEquals(Optional.of(
        new AClass(new BClass("  test  ")))
        .flatMap(aClass -> Optional.ofNullable(aClass.getSomeObject()))
        .flatMap(bClass -> Optional.ofNullable(bClass.getSomeText()))
        .map(String::trim)
        .orElse(""), "test");
  }

  public class AClass {
    private BClass someObject;

    public AClass() {}

    public AClass(BClass someObject) {
      this.someObject = someObject;
    }

    public BClass getSomeObject() {
      return someObject;
    }
  }

  public class BClass {
    private String someText;

    public BClass() {}

    public BClass(String someText) {
      this.someText = someText;
    }

    public String getSomeText() {
      return someText;
    }
  }