如何将pdf文件转为图片

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
public class Pdf2Png {/*** 使用pdfbox将整个pdf转换成图片** @param fileAddress 文件地址 如:C:\\Users\\user\\Desktop\\test* @param filename    PDF文件名不带后缀名* @param type        图片类型 png 和jpg*/public static void pdf2png(String fileAddress, String filename, String type) {long startTime = System.currentTimeMillis();// 将文件地址和文件名拼接成路径 注意：线上环境不能使用\\拼接File file = new File(fileAddress + "\\" + filename + ".pdf");try {// 写入文件PDDocument doc = PDDocument.load(file);PDFRenderer renderer = new PDFRenderer(doc);int pageCount = doc.getNumberOfPages();for (int i = 0; i < pageCount; i++) {// dpi为144，越高越清晰，转换越慢BufferedImage image = renderer.renderImageWithDPI(i, 144); // Windows native DPI// 将图片写出到该路径下ImageIO.write(image, type, new File(fileAddress + "\\" + filename + "_" + (i + 1) + "." + type));}long endTime = System.currentTimeMillis();System.out.println("共耗时：" + ((endTime - startTime) / 1000.0) + "秒");  //转化用时} catch (IOException e) {e.printStackTrace();}}public static void main(String[] args) {pdf2png("C:\\Users\\user\\Desktop\\test", "测试", "png");}
}