在iText中的JavaScript操作中搜索PDF以查找特定字符串

Question

我的目标是在PDF中的注释中查找给定模式的JavaScript.为此,我提供了以下代码:

public static void main(String[] args) {

        try {

            // Reads and parses a PDF document
            PdfReader reader = new PdfReader("Test.pdf");

            // For each PDF page
            for (int i = 1; i <= reader.getNumberOfPages(); i++) {

                // Get a page a PDF page
                PdfDictionary page = reader.getPageN(i);
                // Get all the annotations of page i
                PdfArray annotsArray = page.getAsArray(PdfName.ANNOTS);

                // If page does not have annotations
                if (page.getAsArray(PdfName.ANNOTS) == null) {
                    continue;
                }

                // For each annotation
                for (int j = 0; j < annotsArray.size(); ++j) {

                    // For current annotation
                    PdfDictionary curAnnot = annotsArray.getAsDict(j);

                    // check if has JS as described below
                 PdfDictionary AnnotationAction = AnnotationDictionary.GetAsDict(PdfName.A);
                 // test if it is a JavaScript action
                 if (AnnotationAction.Get(PdfName.S).Equals(PdfName.JavaScript)){
                 // what here?
                 }


                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

据我所知,比较字符串是由StringCompare库完成的.问题是它比较了两个字符串,但我很想知道注释中的JavaScript操作是否以(或包含)此字符串开头:if (this.hostContainer) { try {

那么,如何检查注释中的JavaScript是否包含上述字符串？

使用JS的EDIT示例页面位于:pdf with JS

Answer 1

JavaScript 操作在 ISO 32000-1 中定义如下：

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12.6.4.16 JavaScript 操作

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调用 JavaScript 操作后，符合要求的处理器应执行用 JavaScript 编程语言编写的脚本。根据脚本的性质，文档中的各种交互式表单字段可能会更新其值或更改其视觉外观。Mozilla Development Center\xe2\x80\x99s 客户端 JavaScript 参考和 Adob​​e JavaScript for Acrobat API 参考（请参阅参考书目）详细介绍了 JavaScript 脚本的内容和效果。表 217 显示了特定于此类型动作的动作字典条目。

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表 217 \xe2\x80\x93 特定于 JavaScript 操作的其他条目

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键\n 类型\n 值

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S \n name\n （必需）此字典描述的操作类型；JavaScript 操作应为 JavaScript。

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JS \n 文本字符串或\n 文本流\n （必需）包含要执行的 JavaScript 脚本的文本字符串或文本流。\n 应使用 PDFDocEncoding 或 Unicode 编码（后者由 Unicode 前缀 U+FEFF 标识）对字符串或流的内容进行编码。

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为了支持在JavaScript脚本中使用参数化函数调用，PDF 文档\xe2\x80\x99s 名称字典中的 JavaScript 条目（请参阅 7.7.4，\xe2\x80\x9cName Dictionary\xe2\x80\x9d）可能包含将名称字符串映射到文档级 JavaScript 操作的名称树。打开文档时，应执行此名称树中的所有操作，定义供文档中其他脚本使用的 JavaScript 函数。

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因此，如果您有兴趣知道注释中的 JavaScript 操作是否以此字符串开头（或包含）：if (this.hostContainer) { try {在这种情况下

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 if (AnnotationAction.Get(PdfName.S).Equals(PdfName.JavaScript)){\n // what here?\n }\n

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您可能需要首先检查是否AnnotationAction.Get(PdfName.JS)是 aPdfString或 a PdfStream，在任何一种情况下都以字符串形式检索内容，然后检查它或它调用的任何函数（该函数可能在 JavaScript 名称树中定义）是否包含您搜索的字符串使用通常的字符串比较方法。

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示例代码

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我获取了您的代码，对其进行了一些清理（特别是它是 C# 和 Java 的混合），并添加了如上所述的代码，检查注释操作元素中的直接 JavaScript 代码：

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Java版本

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System.out.println("file.pdf - Looking for special JavaScript actions.");\n// Reads and parses a PDF document\nPdfReader reader = new PdfReader(resource);\n\n// For each PDF page\nfor (int i = 1; i <= reader.getNumberOfPages(); i++)\n{\n    System.out.printf("\\nPage %d\\n", i);\n    // Get a page a PDF page\n    PdfDictionary page = reader.getPageN(i);\n    // Get all the annotations of page i\n    PdfArray annotsArray = page.getAsArray(PdfName.ANNOTS);\n\n    // If page does not have annotations\n    if (annotsArray == null)\n    {\n        System.out.printf("No annotations.\\n", i);\n        continue;\n    }\n\n    // For each annotation\n    for (int j = 0; j < annotsArray.size(); ++j)\n    {\n        System.out.printf("Annotation %d - ", j);\n\n        // For current annotation\n        PdfDictionary curAnnot = annotsArray.getAsDict(j);\n\n        // check if has JS as described below\n        PdfDictionary annotationAction = curAnnot.getAsDict(PdfName.A);\n        if (annotationAction == null)\n        {\n            System.out.print("no action");\n        }\n        // test if it is a JavaScript action\n        else if (PdfName.JAVASCRIPT.equals(annotationAction.get(PdfName.S)))\n        {\n            PdfObject scriptObject = annotationAction.getDirectObject(PdfName.JS);\n            if (scriptObject == null)\n            {\n                System.out.print("missing JS entry");\n                continue;\n            }\n            final String script;\n            if (scriptObject.isString())\n                script = ((PdfString)scriptObject).toUnicodeString();\n            else if (scriptObject.isStream())\n            {\n                try (   ByteArrayOutputStream baos = new ByteArrayOutputStream()    )\n                {\n                    ((PdfStream)scriptObject).writeContent(baos);\n                    script = baos.toString("ISO-8859-1");\n                }\n            }\n            else\n            {\n                System.out.println("malformed JS entry");\n                continue;\n            }\n\n            if (script.contains("if (this.hostContainer) { try {"))\n                System.out.print("contains test string - ");\n\n            System.out.printf("\\n---\\n%s\\n---", script);\n            // what here?\n        }\n        else\n        {\n            System.out.print("no JavaScript action");\n        }\n        System.out.println();\n    }\n}\n

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（测试SearchActionJavaScript，方法testSearchJsActionInFile）

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C#版本

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using (PdfReader reader = new PdfReader(sourcePath))\n{\n    Console.WriteLine("file.pdf - Looking for special JavaScript actions.");\n\n    // For each PDF page\n    for (int i = 1; i <= reader.NumberOfPages; i++)\n    {\n        Console.Write("\\nPage {0}\\n", i);\n        // Get a page a PDF page\n        PdfDictionary page = reader.GetPageN(i);\n        // Get all the annotations of page i\n        PdfArray annotsArray = page.GetAsArray(PdfName.ANNOTS);\n\n        // If page does not have annotations\n        if (annotsArray == null)\n        {\n            Console.WriteLine("No annotations.");\n            continue;\n        }\n\n        // For each annotation\n        for (int j = 0; j < annotsArray.Size; ++j)\n        {\n            Console.Write("Annotation {0} - ", j);\n\n            // For current annotation\n            PdfDictionary curAnnot = annotsArray.GetAsDict(j);\n\n            // check if has JS as described below\n            PdfDictionary annotationAction = curAnnot.GetAsDict(PdfName.A);\n            if (annotationAction == null)\n            {\n                Console.Write("no action");\n            }\n            // test if it is a JavaScript action\n            else if (PdfName.JAVASCRIPT.Equals(annotationAction.Get(PdfName.S)))\n            {\n                PdfObject scriptObject = annotationAction.GetDirectObject(PdfName.JS);\n                if (scriptObject == null)\n                {\n                    Console.WriteLine("missing JS entry");\n                    continue;\n                }\n                String script;\n                if (scriptObject.IsString())\n                    script = ((PdfString)scriptObject).ToUnicodeString();\n                else if (scriptObject.IsStream())\n                {\n                    using (MemoryStream stream = new MemoryStream())\n                    {\n                        ((PdfStream)scriptObject).WriteContent(stream);\n                        script = stream.ToString();\n                    }\n                }\n                else\n                {\n                    Console.WriteLine("malformed JS entry");\n                    continue;\n                }\n\n                if (script.Contains("if (this.hostContainer) { try {"))\n                    Console.Write("contains test string - ");\n\n                Console.Write("\\n---\\n{0}\\n---", script);\n                // what here?\n            }\n            else\n            {\n                Console.Write("no JavaScript action");\n            }\n            Console.WriteLine();\n        }\n    }\n}\n

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输出

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当针对示例文件运行任一版本时，都会得到：

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file.pdf - Looking for special JavaScript actions.\n\nPage 1\nAnnotation 0 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_vii\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 1 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_ix\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 2 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_xi\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 3 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_3\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 4 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_15\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 5 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_37\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 6 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_57\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 7 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_81\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 8 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_111\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 9 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_136\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 10 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_160\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 11 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_197\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 12 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_179\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 13 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_201\', 0]);\n} catch(e) { console.println(e); }};\n---\nAnnotation 14 - contains test string - \n---\nif (this.hostContainer) { try {\nthis.hostContainer.postMessage([\'newPage\', \'pp_223\', 0]);\n} catch(e) { console.println(e); }};\n---\n\nPage 2\nNo annotations.\n\nPage 3\nNo annotations.\n

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