How does below method work in Java?

Question

i am go through the below method but not getting how my seniors designed.

public LinkedHashMap<String,IPDFField> getFields() {
        LinkedHashMap<String, IPDFField> fields = new LinkedHashMap<String, IPDFField>();

        //^field1c^lastName^nameSuffix
        // Line One
        addField(fields,"1_1", new PDFField(27+X_OFF, 718+Y_OFF, new FieldWidthValidation(134F, "^field1_1^firstName^middleName^lastName^nameSuffix")) { //PI tab
            @Override
            public String getPrintableText(Object o) {
                Disposition d = (Disposition) o;
                return dataFormattingService.NormalizedPersonName(
                        d.getFirstName(), d.getMiddleName(), d.getLastName(), d.getNameSuffix()
                );
            }
        });
} //getFileds method ends

from above method they have called below addField Method but what is getPrintableText inside AddField Method

private void addField(HashMap<String, IPDFField> fields, String fieldKey, IPDFField field) {

        field.setFieldKey(fieldKey);
        if (field.getValidation() != null) {
            field.getValidation().setField(field);
        }

        fields.put(fieldKey, field);

    }

above is not full code , the main functionality is we are trying to write content into pdf but i don't want to paste my full code i just need explanation for above logic

Answer 1

  addField(/**/, new PDFField(/**/) { @Override public String getPrintableText(Object o) { // ... } }); 

What happens here is the creation of an anonymous inner class .

This anonymous inner class extends the class PDFField and redefines the behavior of the method getPrintableText which is defined in class PDFField .

---

sorry one more doubt addFiled we have two methods in above , one is anonymous and another is private method,may i know if they are using annonymous class then they could have declared different method name for addField which is private above? – adithyan .p

I'm not sure if I understand that comment...

The anonymous class is

   new PDFField(/**/) { 
        @Override
        public String getPrintableText(Object o) {
          // ...
        }
    }

And this is passed as a parameter to the method addField() .

There is no restriction on the visibility of the method that gets the anonymous class instance as a parameter.