Java中实现PDF文档并排对比及差异高亮显示：使用pdfcompare库

<dependency>
    <groupId>de.red6.pdfcompare</groupId>
    <artifactId>pdfcompare</artifactId>
    <version>4.1.0</version> <!-- 请检查Maven Central获取最新版本 -->
</dependency>

implementation 'de.red6.pdfcompare:pdfcompare:4.1.0' // 请检查Maven Central获取最新版本

import de.red6.pdfcompare.PdfComparator;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class PdfDifferenceHighlighter {

    public static void main(String[] args) {
        // 定义待比较的两个PDF文件路径
        String originalPdfPath = "path/to/your/original.pdf";
        String modifiedPdfPath = "path/to/your/modified.pdf";

        // 定义输出目录和输出文件名称
        String outputDirectory = "path/to/output/diff_results/";
        String outputOriginalHighlighted = outputDirectory + "original_highlighted.pdf";
        String outputModifiedHighlighted = outputDirectory + "modified_highlighted.pdf";

        try {
            // 确保输出目录存在
            Path outputPath = Paths.get(outputDirectory);
            if (!Files.exists(outputPath)) {
                Files.createDirectories(outputPath);
                System.out.println("Output directory created: " + outputDirectory);
            }

            // 1. 创建PdfComparator实例
            // 传入两个PDF文件的路径或输入流
            PdfComparator comparator = new PdfComparator(originalPdfPath, modifiedPdfPath);

            // 2. 执行对比操作
            // compare()方法会执行PDF内容的对比，并返回一个PdfComparisonResult对象
            // 该对象包含了对比结果，如是否存在差异等
            PdfComparator.Result result = comparator.compare();

            // 3. 将高亮差异的PDF写入文件
            // writeTo()方法会生成两个独立的PDF文件，分别对应原始和修改后的文档，
            // 并在各自文件中高亮显示与另一个文档的差异。
            result.writeTo(outputOriginalHighlighted, outputModifiedHighlighted);

            // 4. 判断并输出结果
            if (result.is </del>Different()) { // isDifferent() is the correct method
                System.out.println("PDFs are different. Highlighted versions saved to:");
                System.out.println("  - Original with differences: " + outputOriginalHighlighted);
                System.out.println("  - Modified with differences: " + outputModifiedHighlighted);
            } else {
                System.out.println("PDFs are identical. No differences found.");
            }

        } catch (IOException e) {
            System.err.println("Error during PDF comparison: " + e.getMessage());
            e.printStackTrace();
        } catch (Exception e) {
            System.err.println("An unexpected error occurred: " + e.getMessage());
            e.printStackTrace();
        }
    }
}