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Question

I'm new to java and I am trying to get PDFBOX to rotate a PDF file.. I can't seem to get the error right.. I know it must be something simple but it says The operator < is undefined for the argument type(s) int, Dimension on this line:

for (int i = 0; i < pages.size(); i++) {

And it strikes through size..

My Code:

import java.awt.List;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import org.apache.pdfbox.cos.COSDocument;
import org.apache.pdfbox.pdfparser.PDFParser;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;


public class PdfRotator {


 private static final String pdfFile = null;

    public static void main(String[] args) throws IOException {

PDDocument document = PDDocument.load("PDFrotatorTEST.pdf");



        //public static void main(String[] args) throws Exception {

 List pages = (List) document.getDocumentCatalog().getAllPages();

 for (int i = 0; i < pages.size(); i++) {
     PDPage page = (PDPage) ((java.util.List) pages).get(i);// PDPage page = (PDPage) pages.get(i);
     if ((i + 1) % 2 == 0) {
         page.setRotation(0); 
     }
 }

 File f = new File(pdfFile);// File f = new File(pdfFile);
 String newFile = f.getParent() + File.separator + "out.pdf";
 document.save(newFile);
 document.close();
}
}

Any help would be greatly appreciated

Answer 1

You import the class List as

import java.awt.List;

But that is not the List you want. instead you want

import java.util.List;

---

As the OP is new to java , some backgrounds:

There are several classes called List in the java API and even more in third-party APIs. Thus, when importing a List class , you have to make sure you import the correct one.

In particular there are:

• java.awt.List , a component presents the user with a scrolling list of text items from the Abstract Window Toolkit , the oldest Java GUI API; and
• java.util.List , the interface for an ordered collection (also known as a 'sequence') from the Java Collections Framework .

In your code you are dealing with the result of document.getDocumentCatalog().getAllPages() which returns a list of PDPage instances in a java.util.List object.

---

The error message The operator < is undefined for the argument type(s) int, Dimension is due to the fact that java.awt.List (like java.util.List ) has a method size() but this method returns a java.awt.Dimension (a class that encapsulates the width and height of a component ) and not an int .

Thus, i < pages.size() tries to compare entities which are not naturally comparable.