java压缩pdf文件大小 java pdf压缩到最小

输入 ：包含嵌入式字体的(例如14个)PDF / A-1b文件列表。

处理 ：与Apache PDFBOX进行简单合并。

结果 ：1个PDF / A-1b文件，文件大小太大(太大)。(这几乎是所有源文件大小的总和)。

问题 ：是否可以减小生成的PDF的文件大小？

想法 ：删除多余的嵌入式字体。但是如何？这是正确的做法吗？

不幸的是，以下代码无法完成任务，但突出了明显的问题。

try (PDDocument document = PDDocument.load(new File("E:/tmp/16189_ZU_20181121195111_5544_2008-12-31_Standardauswertung.pdf"))) {
List collectedFonts = new ArrayList<>();
PDPageTree pages = document.getDocumentCatalog().getPages();
int pageNr = 0;
for (PDPage page : pages) {
pageNr++;
Iterable names = page.getResources().getFontNames();
System.out.println("Page " + pageNr);
for (COSName name : names) {
collectedFonts.add(name);
System.out.print("\t" + name + " - ");
PDFont font = page.getResources().getFont(name);
System.out.println(font + ", embedded: " + font.isEmbedded());
page.getCOSObject().removeItem(COSName.F);
page.getResources().getCOSObject().removeItem(name);
}
}
document.save("E:/tmp/output.pdf");
}

该代码产生如下输出：

Page 1
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 2
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 3
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 4
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 5
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 6
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 7
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 8
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 9
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 10
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 11
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F33} - PDTrueTypeFont ArialMT-BoldItalic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 12
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 13
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true
Page 14
COSName{F23} - PDTrueTypeFont ArialMT-Bold, embedded: true
COSName{F25} - PDTrueTypeFont ArialMT-Italic, embedded: true
COSName{F27} - PDTrueTypeFont ArialMT-Regular, embedded: true

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