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jittagornp/PdfSizeUtils.java

Created January 27, 2018 07:27
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  1. jittagornp created this gist Jan 27, 2018.
    112 changes: 112 additions & 0 deletions PdfSizeUtils.java
    View file
    Original file line number Diff line number Diff line change
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    /*
    * Copyright 2018 Pamarin.com
    */
    package com.pamarin.util;

    import com.lowagie.text.Document;
    import com.lowagie.text.DocumentException;
    import com.lowagie.text.PageSize;
    import com.lowagie.text.Rectangle;
    import com.lowagie.text.pdf.PdfContentByte;
    import com.lowagie.text.pdf.PdfImportedPage;
    import com.lowagie.text.pdf.PdfReader;
    import com.lowagie.text.pdf.PdfWriter;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.io.UncheckedIOException;
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;

    /**
    * @author jittagornp <http://jittagornp.me> create : 2018/01/26
    */
    public class PdfSizeUtils {

    private static final Logger LOG = LoggerFactory.getLogger(PdfSizeUtils.class);

    private static final float A4_WIDTH = PageSize.A4.getWidth();

    private static final float A4_HEIGHT = PageSize.A4.getHeight();

    private PdfSizeUtils() {

    }

    private static boolean isA4(float width, float height) {
    return (width == A4_WIDTH && height == A4_HEIGHT);
    }

    public static boolean isA4(File srcPdf) {
    PdfReader reader = null;
    try (InputStream intputStream = new FileInputStream(srcPdf)) {
    reader = new PdfReader(intputStream);
    Rectangle pageSize = reader.getPageSize(1);//first page
    boolean isA4 = isA4(pageSize.getWidth(), pageSize.getHeight());
    LOG.debug("PDF \"{}\"", srcPdf.getAbsolutePath());
    LOG.debug("Size {}x{} (A4 : {}x{}) is A4 => {}",
    pageSize.getWidth(),
    pageSize.getHeight(),
    A4_WIDTH,
    A4_HEIGHT,
    isA4
    );
    return isA4;
    } catch (IOException ex) {
    throw new UncheckedIOException(ex);
    } finally {
    if (reader != null) {
    reader.close();
    }
    }
    }

    public static File convertToA4(File srcPdf, File destFile) {
    try (InputStream intputStream = new FileInputStream(srcPdf);
    OutputStream outputStream = new FileOutputStream(destFile)) {
    PdfReader reader = null;
    PdfWriter writer = null;
    Document document = null;
    try {
    reader = new PdfReader(intputStream);
    document = new Document(new Rectangle(A4_WIDTH, A4_HEIGHT));
    writer = PdfWriter.getInstance(document, outputStream);
    document.open();

    PdfContentByte content = writer.getDirectContent();
    int numberOfPages = reader.getNumberOfPages();
    for (int i = 1; i <= numberOfPages; i++) {
    PdfImportedPage page = writer.getImportedPage(reader, i);
    float scale = getA4Scale(page);
    content.addTemplate(page, scale, 0, 0, scale, 0, 0);
    document.newPage();
    }

    } finally {
    if (document != null) {
    document.close();
    }

    if (writer != null) {
    writer.close();
    }

    if (reader != null) {
    reader.close();
    }
    }
    return destFile;
    } catch (DocumentException | IOException ex) {
    throw new RuntimeException(ex);
    }
    }

    private static float getA4Scale(PdfImportedPage page) {
    float scaleX = A4_WIDTH / page.getWidth();
    float scaleY = A4_HEIGHT / page.getHeight();
    return Math.min(scaleX, scaleY);
    }
    }