在iText中操纵路径、颜色等
我需要分析PDF文件的路径数据，并使用iText 7操作内容。操作包括删除/替换和着色 我可以使用如下代码分析图形：在iText中操纵路径、颜色等,itext,itext7,Itext,Itext7,我需要分析PDF文件的路径数据，并使用iText 7操作内容。操作包括删除/替换和着色 我可以使用如下代码分析图形： public class ContentParsing { public static void main(String[] args) throws IOException { new ContentParsing().inspectPdf("testdata/test.pdf"); } public void inspectPdf(S
public class ContentParsing {
public static void main(String[] args) throws IOException {
new ContentParsing().inspectPdf("testdata/test.pdf");
}
public void inspectPdf(String path) throws IOException {
File file = new File(path);
PdfDocument pdf = new PdfDocument(new PdfReader(file.getAbsolutePath()));
PdfDocumentContentParser parser = new PdfDocumentContentParser(pdf);
for (int i=1; i<=pdf.getNumberOfPages(); i++) {
parser.processContent(i, new PathEventListener());
}
pdf.close();
}
}
public class PathEventListener implements IEventListener {
public void eventOccurred(IEventData eventData, EventType eventType) {
PathRenderInfo pathRenderInfo = (PathRenderInfo) eventData;
for ( Subpath subpath : pathRenderInfo.getPath().getSubpaths() ) {
for ( IShape segment : subpath.getSegments() ) {
// Here goes some path analysis code
System.out.println(segment.getBasePoints());
}
}
}
public Set<EventType> getSupportedEvents() {
Set<EventType> supportedEvents = new HashSet<EventType>();
supportedEvents.add(EventType.RENDER_PATH);
return supportedEvents;
}
}
公共类内容解析{
公共静态void main（字符串[]args）引发IOException{
新ContentParsing（）.inspectPdf（“testdata/test.pdf”）；
}
public void inspectPdf（字符串路径）引发IOException{
文件=新文件（路径）；
PdfDocument pdf=newpdfdocument（newpdfreader（file.getAbsolutePath（））；
PdfDocumentContentParser=新的PdfDocumentContentParser（pdf）；
对于（int i=1；i
现在，如何处理东西并将它们写回PDF？我必须构建一个全新的PDF文档并复制所有内容（以处理过的形式），还是可以直接处理读取的PDF数据
本质上，您正在寻找一个类，它不仅仅是解析PDF内容流并向其中的指令发送信号，就像PdfCanvasProcessor
（您使用的PdfDocumentContentParser
只是PdfCanvasProcessor
的一个非常薄的包装器）但这也会重新创建内容流，并将指令转发回内容流
通用内容流编辑器类
对于iText 5.5.x，可以在中找到此类内容流编辑器类的概念证明（Java版本在答案文本中稍低一点）
这是iText 7的概念验证端口：
public class PdfCanvasEditor extends PdfCanvasProcessor
{
/**
* This method edits the immediate contents of a page, i.e. its content stream.
* It explicitly does not descent into form xobjects, patterns, or annotations.
*/
public void editPage(PdfDocument pdfDocument, int pageNumber) throws IOException
{
if ((pdfDocument.getReader() == null) || (pdfDocument.getWriter() == null))
{
throw new PdfException("PdfDocument must be opened in stamping mode.");
}
PdfPage page = pdfDocument.getPage(pageNumber);
PdfResources pdfResources = page.getResources();
PdfCanvas pdfCanvas = new PdfCanvas(new PdfStream(), pdfResources, pdfDocument);
editContent(page.getContentBytes(), pdfResources, pdfCanvas);
page.put(PdfName.Contents, pdfCanvas.getContentStream());
}
/**
* This method processes the content bytes and outputs to the given canvas.
* It explicitly does not descent into form xobjects, patterns, or annotations.
*/
public void editContent(byte[] contentBytes, PdfResources resources, PdfCanvas canvas)
{
this.canvas = canvas;
processContent(contentBytes, resources);
this.canvas = null;
}
/**
* <p>
* This method writes content stream operations to the target canvas. The default
* implementation writes them as they come, so it essentially generates identical
* copies of the original instructions the {@link ContentOperatorWrapper} instances
* forward to it.
* </p>
* <p>
* Override this method to achieve some fancy editing effect.
* </p>
*/
protected void write(PdfCanvasProcessor processor, PdfLiteral operator, List<PdfObject> operands)
{
PdfOutputStream pdfOutputStream = canvas.getContentStream().getOutputStream();
int index = 0;
for (PdfObject object : operands)
{
pdfOutputStream.write(object);
if (operands.size() > ++index)
pdfOutputStream.writeSpace();
else
pdfOutputStream.writeNewLine();
}
}
//
// constructor giving the parent a dummy listener to talk to
//
public PdfCanvasEditor()
{
super(new DummyEventListener());
}
//
// Overrides of PdfContentStreamProcessor methods
//
@Override
public IContentOperator registerContentOperator(String operatorString, IContentOperator operator)
{
ContentOperatorWrapper wrapper = new ContentOperatorWrapper();
wrapper.setOriginalOperator(operator);
IContentOperator formerOperator = super.registerContentOperator(operatorString, wrapper);
return formerOperator instanceof ContentOperatorWrapper ? ((ContentOperatorWrapper)formerOperator).getOriginalOperator() : formerOperator;
}
//
// members holding the output canvas and the resources
//
protected PdfCanvas canvas = null;
//
// A content operator class to wrap all content operators to forward the invocation to the editor
//
class ContentOperatorWrapper implements IContentOperator
{
public IContentOperator getOriginalOperator()
{
return originalOperator;
}
public void setOriginalOperator(IContentOperator originalOperator)
{
this.originalOperator = originalOperator;
}
@Override
public void invoke(PdfCanvasProcessor processor, PdfLiteral operator, List<PdfObject> operands)
{
if (originalOperator != null && !"Do".equals(operator.toString()))
{
originalOperator.invoke(processor, operator, operands);
}
write(processor, operator, operands);
}
private IContentOperator originalOperator = null;
}
//
// A dummy event listener to give to the underlying canvas processor to feed events to
//
static class DummyEventListener implements IEventListener
{
@Override
public void eventOccurred(IEventData data, EventType type)
{ }
@Override
public Set<EventType> getSupportedEvents()
{
return null;
}
}
}
（测试方法testRemoveBoldMTTextDocument
）
testRemoveBigTextDocument
此示例删除所有使用大字体书写的文本：
try ( InputStream resource = getClass().getResourceAsStream("document.pdf");
PdfReader pdfReader = new PdfReader(resource);
OutputStream result = new FileOutputStream(new File(RESULT_FOLDER, "document-noBigText.pdf"));
PdfWriter pdfWriter = new PdfWriter(result);
PdfDocument pdfDocument = new PdfDocument(pdfReader, pdfWriter) )
{
PdfCanvasEditor editor = new PdfCanvasEditor()
{
@Override
protected void write(PdfCanvasProcessor processor, PdfLiteral operator, List<PdfObject> operands)
{
String operatorString = operator.toString();
if (TEXT_SHOWING_OPERATORS.contains(operatorString))
{
if (getGraphicsState().getFontSize() > 100)
return;
}
super.write(processor, operator, operands);
}
final List<String> TEXT_SHOWING_OPERATORS = Arrays.asList("Tj", "'", "\"", "TJ");
};
for (int i = 1; i <= pdfDocument.getNumberOfPages(); i++)
{
editor.editPage(pdfDocument, i);
}
}
（测试方法testChangeBlackTextToGreenDocument
）
现在，如何处理东西并将它们写回PDF？我必须构建一个全新的PDF文档并复制所有内容（以处理过的形式），还是可以直接处理读取的PDF数据
本质上，您正在寻找一个类，它不仅仅是解析PDF内容流并向其中的指令发送信号，就像PdfCanvasProcessor
（您使用的PdfDocumentContentParser
只是PdfCanvasProcessor
的一个非常薄的包装器）但这也会重新创建内容流，并将指令转发回内容流
通用内容流编辑器类
对于iText 5.5.x，可以在中找到此类内容流编辑器类的概念证明（Java版本在答案文本中稍低一点）
这是iText 7的概念验证端口：
public class PdfCanvasEditor extends PdfCanvasProcessor
{
/**
* This method edits the immediate contents of a page, i.e. its content stream.
* It explicitly does not descent into form xobjects, patterns, or annotations.
*/
public void editPage(PdfDocument pdfDocument, int pageNumber) throws IOException
{
if ((pdfDocument.getReader() == null) || (pdfDocument.getWriter() == null))
{
throw new PdfException("PdfDocument must be opened in stamping mode.");
}
PdfPage page = pdfDocument.getPage(pageNumber);
PdfResources pdfResources = page.getResources();
PdfCanvas pdfCanvas = new PdfCanvas(new PdfStream(), pdfResources, pdfDocument);
editContent(page.getContentBytes(), pdfResources, pdfCanvas);
page.put(PdfName.Contents, pdfCanvas.getContentStream());
}
/**
* This method processes the content bytes and outputs to the given canvas.
* It explicitly does not descent into form xobjects, patterns, or annotations.
*/
public void editContent(byte[] contentBytes, PdfResources resources, PdfCanvas canvas)
{
this.canvas = canvas;
processContent(contentBytes, resources);
this.canvas = null;
}
/**
* <p>
* This method writes content stream operations to the target canvas. The default
* implementation writes them as they come, so it essentially generates identical
* copies of the original instructions the {@link ContentOperatorWrapper} instances
* forward to it.
* </p>
* <p>
* Override this method to achieve some fancy editing effect.
* </p>
*/
protected void write(PdfCanvasProcessor processor, PdfLiteral operator, List<PdfObject> operands)
{
PdfOutputStream pdfOutputStream = canvas.getContentStream().getOutputStream();
int index = 0;
for (PdfObject object : operands)
{
pdfOutputStream.write(object);
if (operands.size() > ++index)
pdfOutputStream.writeSpace();
else
pdfOutputStream.writeNewLine();
}
}
//
// constructor giving the parent a dummy listener to talk to
//
public PdfCanvasEditor()
{
super(new DummyEventListener());
}
//
// Overrides of PdfContentStreamProcessor methods
//
@Override
public IContentOperator registerContentOperator(String operatorString, IContentOperator operator)
{
ContentOperatorWrapper wrapper = new ContentOperatorWrapper();
wrapper.setOriginalOperator(operator);
IContentOperator formerOperator = super.registerContentOperator(operatorString, wrapper);
return formerOperator instanceof ContentOperatorWrapper ? ((ContentOperatorWrapper)formerOperator).getOriginalOperator() : formerOperator;
}
//
// members holding the output canvas and the resources
//
protected PdfCanvas canvas = null;
//
// A content operator class to wrap all content operators to forward the invocation to the editor
//
class ContentOperatorWrapper implements IContentOperator
{
public IContentOperator getOriginalOperator()
{
return originalOperator;
}
public void setOriginalOperator(IContentOperator originalOperator)
{
this.originalOperator = originalOperator;
}
@Override
public void invoke(PdfCanvasProcessor processor, PdfLiteral operator, List<PdfObject> operands)
{
if (originalOperator != null && !"Do".equals(operator.toString()))
{
originalOperator.invoke(processor, operator, operands);
}
write(processor, operator, operands);
}
private IContentOperator originalOperator = null;
}
//
// A dummy event listener to give to the underlying canvas processor to feed events to
//
static class DummyEventListener implements IEventListener
{
@Override
public void eventOccurred(IEventData data, EventType type)
{ }
@Override
public Set<EventType> getSupportedEvents()
{
return null;
}
}
}
（测试方法testRemoveBoldMTTextDocument
）
testRemoveBigTextDocument
此示例删除所有使用大字体书写的文本：
try ( InputStream resource = getClass().getResourceAsStream("document.pdf");
PdfReader pdfReader = new PdfReader(resource);
OutputStream result = new FileOutputStream(new File(RESULT_FOLDER, "document-noBigText.pdf"));
PdfWriter pdfWriter = new PdfWriter(result);
PdfDocument pdfDocument = new PdfDocument(pdfReader, pdfWriter) )
{
PdfCanvasEditor editor = new PdfCanvasEditor()
{
@Override
protected void write(PdfCanvasProcessor processor, PdfLiteral operator, List<PdfObject> operands)
{
String operatorString = operator.toString();
if (TEXT_SHOWING_OPERATORS.contains(operatorString))
{
if (getGraphicsState().getFontSize() > 100)
return;
}
super.write(processor, operator, operands);
}
final List<String> TEXT_SHOWING_OPERATORS = Arrays.asList("Tj", "'", "\"", "TJ");
};
for (int i = 1; i <= pdfDocument.getNumberOfPages(); i++)
{
editor.editPage(pdfDocument, i);
}
}
（测试方法testChangeBlackTextToGreenDocument
）创建一个新的pdf并添加修改后的内容可能是让您完全控制的最佳方式。修改现有pdf在技术上是可行的，使用iText可以很容易地完成一些任务，如在现有内容上/下添加内容或使用不同颜色突出显示。其他任务，尤其是文本替换t或search包含很多陷阱，技术上很难。我建议大家看看并浏览一些示例和教程，看看有什么可能。创建一个新的pdf并添加修改后的内容可能是最好的方法，可以让你完全控制。修改现有的pdf在技术上是可行的，等等使用iText，在现有内容上方/下方添加内容或使用不同颜色突出显示等任务非常容易。其他任务，尤其是文本替换或搜索等任务，包含大量陷阱，技术难度较大。我建议查看并浏览一些示例和教程，看看可能的情况。W哦，一个非常彻底的答案！我将花一些时间来研究它。非常感谢！只是为了让使用示例完整-似乎应该有pdfDocument.close（）
在三个使用示例中的for
循环之后，对吗？至少如果我不添加它，我只会得到一个空文件。或者这只是Java 1.8的问题吗？@Thomas示例中的PdfDocument PdfDocument
实例会自动关闭，因为它们被相应地定义try（这里）{…}
。啊，我明白了。Eclipse抱怨尝试使用资源，所以我删除了它以获得一个基本版本来修补。以前没有做过很多Java工作-我认识到在Eclipse中，我必须右键单击项目，选择Properties/Java Compiler并将“Compiler compliance settings”设置为“1.7”。你的PdfCanvasProcessor类是如何获得许可的？我在你发布它的网站上没有看到许可证。哇，一个非常彻底的答案！我需要花一些时间来研究它。非常感谢！只是为了让使用示例完整-似乎应该有pdfDocument.close（）
在三个使用示例中的for
循环之后，对吗？至少如果我不添加它，我只会得到一个空文件。或者这只是Java 1.8的问题吗？@Thomas示例中的PdfDocument PdfDocument
实例会自动关闭，因为它们被相应地定义try（这里）{…}
。啊，我明白了。Eclipse抱怨尝试使用资源，所以我删除了它以获得一个基本版本来修补。以前没有做过很多Java工作-我认识到在Eclipse中，我必须右键单击项目，选择Properties/Java Compiler并将“Compiler compliance settings”设置为“1.7”.您的PdfCanvasProcessor类是如何获得许可的？我在您发布它的位置上没有看到许可证。