IText5实现PDF签章流程

不念不忘少年蓝@ 2023-07-18 03:28 25阅读 0赞

public class ReadMe  {
    
        public static void main(String[] args) throws Exception {
    
    
            //1、创建PDF阅读器
            PdfReader pdfReader = new PdfReader("需要签章的PDF文件路径");
    
            //2、创建签章工具PdfStamper
            //最后一个参数false的话：PDF文件只允许被签名一次，多次签名时最后一次有效；true的话：可以被追加签名，验签工具可以识别出每次签名之后文档是否被修改
            PdfStamper pdfStamper = PdfStamper.createSignature(pdfReader, new FileOutputStream("签章后的PDF文件路径"),
                    '\0', null, true);
    
    
            //3、创建数字签名域
            int x = 300, y = 400, width = 200, height = 200;
            Rectangle areaSignatureRect = new Rectangle(x, y, x + width, y + height);  //签名区域
            PdfFormField formField = PdfFormField.createSignature(pdfStamper.getWriter());
            formField.setFieldName("AREA_SIGNATURE");  //签名域标识
            formField.setPage(1);  //PDF页码从1开始
            formField.setWidget(areaSignatureRect, PdfAnnotation.HIGHLIGHT_OUTLINE);  //高亮显示
            //可以通过PdfAppearance对象对这块区域外观做下调整
            PdfAppearance pdfAppearance = PdfAppearance.createAppearance(pdfStamper.getWriter(), width, height); //设置区域的宽高和边框厚度
            pdfAppearance.setColorStroke(BaseColor.LIGHT_GRAY);  //边框颜色
            pdfAppearance.setColorFill(BaseColor.YELLOW);  //填充颜色
            //填充矩形区域-开始
            pdfAppearance.rectangle(0, 0, width, height);
            //填充矩形区域-结束
            pdfAppearance.fillStroke();
            //添加文字
            pdfAppearance.setColorFill(BaseColor.BLACK);  //填充颜色重置为黑色，用于显示文字
            ColumnText.showTextAligned(pdfAppearance, Element.ALIGN_CENTER, new Phrase("签名区域",
                    new Font(Font.FontFamily.SYMBOL, 9.0F, Font.NORMAL, new BaseColor(0.0F, 0.0F, 0.0F, 0.5F))),
                    width / 2, height / 2, 0);
            //将外观应用到签名域对象上
            formField.setAppearance(PdfAnnotation.APPEARANCE_NORMAL, pdfAppearance);
            //最后将签名对象作为标注添加到PdfStamper对象
            pdfStamper.addAnnotation(formField, 1);
    
    
    
    
            //3、获取数字签章属性对象，设定数字签章属性（对签名域的属性进行调整）
            PdfSignatureAppearance appearance = pdfStamper.getSignatureAppearance();
            appearance.setReason("签名原因，显示在PDF签名属性中");
            appearance.setLocation("签名地点，显示在PDF签名属性中");
            //设置签名的位置，页码、签名域名称，多次追加签名的时候签名域名称不能一样
            appearance.setVisibleSignature(new Rectangle(200, 200, 300, 300), 1, "sig1");
            //读取印章图片
            Image image = Image.getInstance("C:\\gongzhang.png");
            appearance.setSignatureGraphic(image);
            appearance.setCertificationLevel(PdfSignatureAppearance.NOT_CERTIFIED);
            //设置图章的显示方式，如下选择的只是显示图章（还有其他模式，可以图章和签名描述一起显示）
            appearance.setRenderingMode(PdfSignatureAppearance.RenderingMode.GRAPHIC);
    
            //这里iText提供了两个用于签名的接口，可以自己实现
            ExternalDigest digest = new BouncyCastleDigest();  //摘要算法
            //读取keystore，获取私钥和证书链
            KeyStore ks = KeyStore.getInstance("PKCS12");
            ks.load(new FileInputStream("C:\\pdf\\test.p12"), "111111".toCharArray());
            String alias = ks.aliases().nextElement();
            PrivateKey pk = (PrivateKey) ks.getKey(alias, "111111".toCharArray());  //签名私钥
            ExternalSignature signature = new PrivateKeySignature(pk, DigestAlgorithms.SHA1, null);  //签名算法
            Certificate[] chain = ks.getCertificateChain(alias);  //证书链
            MakeSignature.CryptoStandard subFilter = MakeSignature.CryptoStandard.CMS;  //数字签名格式，iText有两种
    
            //调用iText签名方法完成PDF签章
            MakeSignature.signDetached(appearance, digest, signature, chain, null, null, null,
                    0, subFilter);
    
        }
    }

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