pdf转base64参考百度经验:https://jingyan.baidu.com/article/59a015e3770f58f7948865eb.html图片/PDF转Base64首先了解下如何最简单转base64,这里用到jdk中的BASE64Encoder,其中byte[] bytes为字节数组的文件(下列代码中是图片) BASE64Encoder encoder = new BASE64Encoder();// encode、encodeBuffer均可,由于该方法转换的字符中含换行符// 因此使用replaceAll替换掉所有换行符 String encode1 = encoder.encodeBuffer(bytes).trim().replaceAll("\r\n",""); String encode2 = encoder.encode(bytes).trim().replaceAll("\r\n","");// 根据文件类型添加data:信息,例如下列是图片// PDF可写成data:application/pdf;base64 System.out.println("data:image/png;base64,"+encode2);如果上述byte[] bytes数组为pdf的话即添加data:application/pdf;base64前端HTML显示PDF可以用iframe引用实现<iframe src="data:application/pdf;base64,这里是base64主体内容" style="width:100%;height:100%"></iframe>如果引用base64图片则为<img src="data:image/png;base64,***************************************************"/>PDF转图片转Base64使用Free Spire.PDF for JAVA,官网:http://e-iceblue.cn/Downloads/Free-Spire-PDF-JAVA.htmlFree Spire.PDF for JAVA是一款完全免费的PDF Java组件,开发人员可以使用它在Java应用程序中进行创建PDF、读取PDF和保存PDF等操作,并且无需安装Adobe Acrobat。 //加载PDF文件 PdfDocument doc = new PdfDocument(); doc.loadFromFile("d:/pdf/test.pdf"); //保存PDF的每一页到图片 BufferedImage image; for (int i = 0; i < doc.getPages().getCount(); i++) { image = doc.saveAsImage(i); File file = new File(String.format("d:/pdf/ToImage-img-%d.png", i));//指定图片文件 ImageIO.write(image, "PNG", file);//写入图片到文件 ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); ImageIO.write(image, "png", outputStream);//也可将图片写入进流 byte[] bytes = outputStream.toByteArray();//将流转换成byte[]// 下述使用工具类来进行Base64编码 System.out.println("data:image/png;base64," + Base64Utils.encode(bytes)); } doc.close();Base64工具类public class Base64Utils { private static char[] base64EncodeChars = new char[] {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'}; private static byte[] base64DecodeChars = new byte[] {-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1}; public static String encode(byte[] data) { StringBuffer sb = new StringBuffer(); int len = data.length; int i = 0; int b1, b2, b3; while (i < len) { b1 = data[i++] & 0xff; if (i == len) { sb.append(base64EncodeChars[b1 >>> 2]); sb.append(base64EncodeChars[(b1 & 0x3) << 4]); sb.append("=="); break; } b2 = data[i++] & 0xff; if (i == len) { sb.append(base64EncodeChars[b1 >>> 2]); sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]); sb.append(base64EncodeChars[(b2 & 0x0f) << 2]); sb.append("="); break; } b3 = data[i++] & 0xff; sb.append(base64EncodeChars[b1 >>> 2]); sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]); sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]); sb.append(base64EncodeChars[b3 & 0x3f]); } return sb.toString(); } public static byte[] decode(String str) { try { return decodePrivate(str); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return new byte[] {}; } private static byte[] decodePrivate(String str) throws UnsupportedEncodingException { StringBuffer sb = new StringBuffer(); byte[] data = null; data = str.getBytes("US-ASCII"); int len = data.length; int i = 0; int b1, b2, b3, b4; while (i < len) { do { b1 = base64DecodeChars[data[i++]]; } while (i < len && b1 == -1); if (b1 == -1) break; do { b2 = base64DecodeChars[data[i++]]; } while (i < len && b2 == -1); if (b2 == -1) break; sb.append((char) ((b1 << 2) | ((b2 & 0x30) >>> 4))); do { b3 = data[i++]; if (b3 == 61) return sb.toString().getBytes("iso8859-1"); b3 = base64DecodeChars[b3]; } while (i < len && b3 == -1); if (b3 == -1) break; sb.append((char) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2))); do { b4 = data[i++]; if (b4 == 61) return sb.toString().getBytes("iso8859-1"); b4 = base64DecodeChars[b4]; } while (i < len && b4 == -1); if (b4 == -1) break; sb.append((char) (((b3 & 0x03) << 6) | b4)); } return sb.toString().getBytes("iso8859-1"); }}或者使用itext包效果一样,依赖如下:<!-- https://mvnrepository.com/artifact/com.itextpdf/itextpdf --><dependency> <groupId>com.itextpdf</groupId> <artifactId>itextpdf</artifactId> <version>5.5.13</version></dependency><!-- https://mvnrepository.com/artifact/org.apache.pdfbox/pdfbox --><dependency> <groupId>org.apache.pdfbox</groupId> <artifactId>pdfbox</artifactId> <version>2.0.12</version></dependency>代码如下:import com.itextpdf.text.pdf.PdfReader;import org.apache.pdfbox.pdmodel.PDDocument;import org.apache.pdfbox.rendering.PDFRenderer;import sun.misc.BASE64Encoder;import javax.imageio.ImageIO;import java.awt.image.BufferedImage;import java.io.*;public class TEXT { public static void main(String[] args) throws IOException { String path = "D:/a.pdf"; File file = new File(path); BASE64Encoder encoder = new sun.misc.BASE64Encoder(); FileInputStream is=new FileInputStream(file); byte[] pdf=new byte[is.available()]; is.read(pdf); is.close(); PDDocument pdDocument = PDDocument.load(pdf); PDFRenderer renderer = new PDFRenderer(pdDocument); PdfReader reader = new PdfReader(pdf); int pageNum = reader.getNumberOfPages(); for (int j = 0; j < pageNum; j++) { BufferedImage image = renderer.renderImageWithDPI(j, 100); ByteArrayOutputStream baos = new ByteArrayOutputStream(); ImageIO.write(image, "png", baos); baos.flush(); byte[] imageInByte = baos.toByteArray(); String base64 = encoder.encode(imageInByte).trim().replaceAll("\r\n",""); baos.close(); System.out.println("data:image/png;base64,"+base64); } reader.close(); }}