Java如何解压pdf压缩包并提取pdf当中的图片

你可以使用Java的压缩包处理库和PDF处理库来解压缩PDF压缩包并提取其中的图片。下面是一个基本的示例代码：

import java.io.*;
import java.util.zip.*;
import org.apache.pdfbox.pdmodel.*;
import org.apache.pdfbox.rendering.*;

public class PDFImageExtractor {
    public static void main(String[] args) {
        String compressedPdfFilePath = "path/to/compressed.pdf";
        String outputDirectoryPath = "path/to/output";
        
        try {
            // 解压缩PDF压缩包
            unzip(compressedPdfFilePath, outputDirectoryPath);
            
            // 提取图片
            extractImages(outputDirectoryPath);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static void unzip(String compressedFilePath, String outputDirectoryPath) throws IOException {
        byte[] buffer = new byte[1024];
        
        try (ZipInputStream zipInputStream = new ZipInputStream(new FileInputStream(compressedFilePath))) {
            ZipEntry zipEntry = zipInputStream.getNextEntry();
            
            while (zipEntry != null) {
                String fileName = zipEntry.getName();
                File newFile = new File(outputDirectoryPath + File.separator + fileName);
                
                if (zipEntry.isDirectory()) {
                    newFile.mkdirs();
                } else {
                    new File(newFile.getParent()).mkdirs();
                    try (FileOutputStream fos = new FileOutputStream(newFile)) {
                        int len;
                        while ((len = zipInputStream.read(buffer)) > 0) {
                            fos.write(buffer, 0, len);
                        }
                    }
                }
                
                zipEntry = zipInputStream.getNextEntry();
            }
            
            zipInputStream.closeEntry();
        }
    }

    public static void extractImages(String directoryPath) throws IOException {
        try (PDDocument document = PDDocument.load(new File(directoryPath + File.separator + "compressed.pdf"))) {
            PDFRenderer pdfRenderer = new PDFRenderer(document);
            
            for (int pageIndex = 0; pageIndex < document.getNumberOfPages(); pageIndex++) {
                BufferedImage image = pdfRenderer.renderImageWithDPI(pageIndex, 300, ImageType.RGB);
                ImageIO.write(image, "PNG", new File(directoryPath + File.separator + "image_" + pageIndex + ".png"));
            }
        }
    }
}

请注意，以上示例代码基于Apache PDFBox库进行PDF处理，并使用Java的内置库进行压缩包处理。你需要将`path/to/compressed.pdf`替换为你实际的PDF压缩包路径，将`path/to/output`替换为你希望保存提取的图片的输出目录路径。