Java 如何使用Apache pdfbox在PDF中生成多行

How to generate multiple lines in PDF using Apache pdfbox

提问by Ronald James Pulpel

I am using Pdfbox to generate PDF files using Java. The problem is that when i add long text contents in the document, it is not displayed properly. Only a part of it is displayed. That too in a single line.

我正在使用 Pdfbox 使用 Java 生成 PDF 文件。问题是当我在文档中添加长文本内容时，它无法正确显示。仅显示其中的一部分。这也是在一行中。

I want text to be in multiple lines.

我希望文本在多行中。

My code is given below:

我的代码如下：

PDPageContentStream pdfContent=new PDPageContentStream(pdfDocument, pdfPage, true, true);

pdfContent.beginText();
pdfContent.setFont(pdfFont, 11);
pdfContent.moveTextPositionByAmount(30,750);            
pdfContent.drawString("I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox");
pdfContent.endText();

My output:

我的输出：

采纳答案by mkl

Adding to the answer of Mark you might want to know where to split your long string. You can use the PDFontmethod getStringWidthfor that.

添加到马克的答案中，您可能想知道在哪里拆分长字符串。您可以使用该PDFont方法getStringWidth。

Putting everything together you get something like this (with minor differences depending on the PDFBox version):

把所有东西放在一起，你会得到这样的东西（根据 PDFBox 版本有细微差别）：

PDFBox 1.8.x

PDFBox 1.8.x

PDDocument doc = null;
try
{
    doc = new PDDocument();
    PDPage page = new PDPage();
    doc.addPage(page);
    PDPageContentStream contentStream = new PDPageContentStream(doc, page);

    PDFont pdfFont = PDType1Font.HELVETICA;
    float fontSize = 25;
    float leading = 1.5f * fontSize;

    PDRectangle mediabox = page.findMediaBox();
    float margin = 72;
    float width = mediabox.getWidth() - 2*margin;
    float startX = mediabox.getLowerLeftX() + margin;
    float startY = mediabox.getUpperRightY() - margin;

    String text = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox"; 
    List<String> lines = new ArrayList<String>();
    int lastSpace = -1;
    while (text.length() > 0)
    {
        int spaceIndex = text.indexOf(' ', lastSpace + 1);
        if (spaceIndex < 0)
            spaceIndex = text.length();
        String subString = text.substring(0, spaceIndex);
        float size = fontSize * pdfFont.getStringWidth(subString) / 1000;
        System.out.printf("'%s' - %f of %f\n", subString, size, width);
        if (size > width)
        {
            if (lastSpace < 0)
                lastSpace = spaceIndex;
            subString = text.substring(0, lastSpace);
            lines.add(subString);
            text = text.substring(lastSpace).trim();
            System.out.printf("'%s' is line\n", subString);
            lastSpace = -1;
        }
        else if (spaceIndex == text.length())
        {
            lines.add(text);
            System.out.printf("'%s' is line\n", text);
            text = "";
        }
        else
        {
            lastSpace = spaceIndex;
        }
    }

    contentStream.beginText();
    contentStream.setFont(pdfFont, fontSize);
    contentStream.moveTextPositionByAmount(startX, startY);            
    for (String line: lines)
    {
        contentStream.drawString(line);
        contentStream.moveTextPositionByAmount(0, -leading);
    }
    contentStream.endText(); 
    contentStream.close();

    doc.save("break-long-string.pdf");
}
finally
{
    if (doc != null)
    {
        doc.close();
    }
}

(BreakLongString.javatest testBreakStringfor PDFBox 1.8.x)

（PDFBox 1.8.x 的BreakLongString.java测试testBreakString）

PDFBox 2.0.x

PDFBox 2.0.x

PDDocument doc = null;
try
{
    doc = new PDDocument();
    PDPage page = new PDPage();
    doc.addPage(page);
    PDPageContentStream contentStream = new PDPageContentStream(doc, page);

    PDFont pdfFont = PDType1Font.HELVETICA;
    float fontSize = 25;
    float leading = 1.5f * fontSize;

    PDRectangle mediabox = page.getMediaBox();
    float margin = 72;
    float width = mediabox.getWidth() - 2*margin;
    float startX = mediabox.getLowerLeftX() + margin;
    float startY = mediabox.getUpperRightY() - margin;

    String text = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox"; 
    List<String> lines = new ArrayList<String>();
    int lastSpace = -1;
    while (text.length() > 0)
    {
        int spaceIndex = text.indexOf(' ', lastSpace + 1);
        if (spaceIndex < 0)
            spaceIndex = text.length();
        String subString = text.substring(0, spaceIndex);
        float size = fontSize * pdfFont.getStringWidth(subString) / 1000;
        System.out.printf("'%s' - %f of %f\n", subString, size, width);
        if (size > width)
        {
            if (lastSpace < 0)
                lastSpace = spaceIndex;
            subString = text.substring(0, lastSpace);
            lines.add(subString);
            text = text.substring(lastSpace).trim();
            System.out.printf("'%s' is line\n", subString);
            lastSpace = -1;
        }
        else if (spaceIndex == text.length())
        {
            lines.add(text);
            System.out.printf("'%s' is line\n", text);
            text = "";
        }
        else
        {
            lastSpace = spaceIndex;
        }
    }

    contentStream.beginText();
    contentStream.setFont(pdfFont, fontSize);
    contentStream.newLineAtOffset(startX, startY);
    for (String line: lines)
    {
        contentStream.showText(line);
        contentStream.newLineAtOffset(0, -leading);
    }
    contentStream.endText(); 
    contentStream.close();

    doc.save(new File(RESULT_FOLDER, "break-long-string.pdf"));
}
finally
{
    if (doc != null)
    {
        doc.close();
    }
}

(BreakLongString.javatest testBreakStringfor PDFBox 2.0.x)

（PDFBox 2.0.x 的BreakLongString.java测试testBreakString）

The result

结果

This looks as expected.

这看起来像预期的那样。

Of course there are numerous improvements to make but this should show how to do it.

当然，还有许多改进要做，但这应该说明如何去做。

Adding unconditional line breaks

添加无条件换行符

In a comment aleskv asked:

在评论中，aleskv 问道：

could you add line breaks when there are \n in the string?

当字符串中有 \n 时，您可以添加换行符吗？

One can easily extend the solution to unconditionally break at newline characters by first splitting the string at '\n' characters and then iterating over the split result.

通过首先在 '\n' 字符处拆分字符串，然后迭代拆分结果，可以轻松地将解决方案扩展到在换行符处无条件中断。

E.g. if instead of the long string from above

例如，如果不是上面的长字符串

String text = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox"; 

you want to process this even longer string with embedded new line characters

你想用嵌入的换行符处理这个更长的字符串

String textNL = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox.\nFurthermore, I have added some newline characters to the string at which lines also shall be broken.\nIt should work alright like this...";

you can simply replace

你可以简单地替换

String text = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox"; 
List<String> lines = new ArrayList<String>();
int lastSpace = -1;
while (text.length() > 0)
{
    [...]
}

in the solutions above by

在上述解决方案中

String textNL = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox.\nFurthermore, I have added some newline characters to the string at which lines also shall be broken.\nIt should work alright like this..."; 
List<String> lines = new ArrayList<String>();
for (String text : textNL.split("\n"))
{
    int lastSpace = -1;
    while (text.length() > 0)
    {
        [...]
    }
}

(from BreakLongString.javatest testBreakStringNL)

（来自BreakLongString.java测试testBreakStringNL）

The result:

结果：

回答by Mark Waschkowski

Just draw the string in a position below, typically done within a loop:

只需在下面的位置绘制字符串，通常在循环中完成：

float textx = margin+cellMargin;
float texty = y-15;
for(int i = 0; i < content.length; i++){
    for(int j = 0 ; j < content[i].length; j++){
        String text = content[i][j];
        contentStream.beginText();
        contentStream.moveTextPositionByAmount(textx,texty);
        contentStream.drawString(text);
        contentStream.endText();
        textx += colWidth;
    }
    texty-=rowHeight;
    textx = margin+cellMargin;
}

These are the important lines:

这些是重要的线路：

contentStream.beginText();
contentStream.moveTextPositionByAmount(textx,texty);
contentStream.drawString(text);
contentStream.endText();

Just keep drawing new strings in new positions. For an example using a table, see here: http://fahdshariff.blogspot.ca/2010/10/creating-tables-with-pdfbox.html

只需在新位置继续绘制新字符串即可。有关使用表格的示例，请参见此处：http: //fahdshariff.blogspot.ca/2010/10/creating-tables-with-pdfbox.html

回答by Bharathiraja

contentStream.moveTextPositionByAmount(textx,texty) is key point.

contentStream.moveTextPositionByAmount(textx,texty) 是关键点。

say for example if you are using a A4 size means 580,800 is width and height correspondling(approximately). so you have move your text based on the position of your document size.

例如，如果您使用 A4 尺寸意味着 580,800 是宽度和高度对应的（大约）。因此您可以根据文档大小的位置移动文本。

PDFBox supports varies page format . so the height and width will vary for different page format

PDFBox 支持各种页面格式。所以高度和宽度会因不同的页面格式而异

回答by Michael Woywod

I know it's a bit late, but i had a little problem with mkl's solution. If the last line would only contain one word, your algorithm writes it on the previous one.

我知道这有点晚了，但我对 mkl 的解决方案有一点问题。如果最后一行只包含一个单词，您的算法会将其写入前一行。

For Example: "Lorem ipsum dolor sit amet" is your text and it should add a line break after "sit".

例如：“Lorem ipsum dolor sat amet”是您的文本，它应该在“sit”之后添加一个换行符。

Lorem ipsum dolor sit
amet

But it does this:

但它这样做：

Lorem ipsum dolor sit amet

I came up with my own solution i want to share with you.

我想出了我自己的解决方案，我想与您分享。

/**
 * @param text The text to write on the page.
 * @param x The position on the x-axis.
 * @param y The position on the y-axis.
 * @param allowedWidth The maximum allowed width of the whole text (e.g. the width of the page - a defined margin).
 * @param page The page for the text.
 * @param contentStream The content stream to set the text properties and write the text.
 * @param font The font used to write the text.
 * @param fontSize The font size used to write the text.
 * @param lineHeight The line height of the font (typically 1.2 * fontSize or 1.5 * fontSize).
 * @throws IOException
 */
private void drawMultiLineText(String text, int x, int y, int allowedWidth, PDPage page, PDPageContentStream contentStream, PDFont font, int fontSize, int lineHeight) throws IOException {

    List<String> lines = new ArrayList<String>();

    String myLine = "";

    // get all words from the text
    // keep in mind that words are separated by spaces -> "Lorem ipsum!!!!:)" -> words are "Lorem" and "ipsum!!!!:)"
    String[] words = text.split(" ");
    for(String word : words) {

        if(!myLine.isEmpty()) {
            myLine += " ";
        }

        // test the width of the current line + the current word
        int size = (int) (fontSize * font.getStringWidth(myLine + word) / 1000);
        if(size > allowedWidth) {
            // if the line would be too long with the current word, add the line without the current word
            lines.add(myLine);

            // and start a new line with the current word
            myLine = word;
        } else {
            // if the current line + the current word would fit, add the current word to the line
            myLine += word;
        }
    }
    // add the rest to lines
    lines.add(myLine);

    for(String line : lines) {
        contentStream.beginText();
        contentStream.setFont(font, fontSize);
        contentStream.moveTextPositionByAmount(x, y);
        contentStream.drawString(line);
        contentStream.endText();

        y -= lineHeight;
    }

}

回答by Vinayak Nathjogi

///// FOR PDBOX 2.0.X
//  FOR ADDING DYNAMIC PAGE ACCORDING THE LENGTH OF THE CONTENT

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDType1Font;

public class Document_Creation {

   public static void main (String args[]) throws IOException {

       PDDocument doc = null;
       try
       {
           doc = new PDDocument();
           PDPage page = new PDPage();
           doc.addPage(page);
           PDPageContentStream contentStream = new PDPageContentStream(doc, page);

           PDFont pdfFont = PDType1Font.HELVETICA;
           float fontSize = 25;
           float leading = 1.5f * fontSize;

           PDRectangle mediabox = page.getMediaBox();
           float margin = 72;
           float width = mediabox.getWidth() - 2*margin;
           float startX = mediabox.getLowerLeftX() + margin;
           float startY = mediabox.getUpperRightY() - margin;

           String text = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox.An essay is, generally, a piece of writing that gives the author's own argument — but the definition is vague, overlapping with those of an article, a pamphlet, and a short story. Essays have traditionally been sub-classified as formal and informal. Formal essays are characterized by serious purpose, dignity, logical organization, length,whereas the informal essay is characterized by the personal element (self-revelation, individual tastes and experiences, confidential manner), humor, graceful style, rambling structure, unconventionality or novelty of theme.Lastly, one of the most attractive features of cats as housepets is their ease of care. Cats do not have to be walked. They get plenty of exercise in the house as they play, and they do their business in the litter box. Cleaning a litter box is a quick, painless procedure. Cats also take care of their own grooming. Bathing a cat is almost never necessary because under ordinary circumstances cats clean themselves. Cats are more particular about personal cleanliness than people are. In addition, cats can be left home alone for a few hours without fear. Unlike some pets, most cats will not destroy the furnishings when left alone. They are content to go about their usual activities until their owners return."; 
           List<String> lines = new ArrayList<String>();
           int lastSpace = -1;
           while (text.length() > 0)
           {
               int spaceIndex = text.indexOf(' ', lastSpace + 1);
               if (spaceIndex < 0)
                   spaceIndex = text.length();
               String subString = text.substring(0, spaceIndex);
               float size = fontSize * pdfFont.getStringWidth(subString) / 1000;
               System.out.printf("'%s' - %f of %f\n", subString, size, width);
               if (size > width)
               {
                   if (lastSpace < 0)
                       lastSpace = spaceIndex;
                   subString = text.substring(0, lastSpace);
                   lines.add(subString);
                   text = text.substring(lastSpace).trim();
                   System.out.printf("'%s' is line\n", subString);
                   lastSpace = -1;
               }
               else if (spaceIndex == text.length())
               {
                   lines.add(text);
                   System.out.printf("'%s' is line\n", text);
                   text = "";
               }
               else
               {
                   lastSpace = spaceIndex;
               }
           }

           contentStream.beginText();
           contentStream.setFont(pdfFont, fontSize);
           contentStream.newLineAtOffset(startX, startY);
           float currentY=startY;
           for (String line: lines)
           {
               currentY -=leading;

               if(currentY<=margin)
               {

                   contentStream.endText(); 
                   contentStream.close();
                   PDPage new_Page = new PDPage();
                   doc.addPage(new_Page);
                   contentStream = new PDPageContentStream(doc, new_Page);
                   contentStream.beginText();
                   contentStream.setFont(pdfFont, fontSize);
                   contentStream.newLineAtOffset(startX, startY);
                   currentY=startY;
               }
               contentStream.showText(line);
               contentStream.newLineAtOffset(0, -leading);
           }
           contentStream.endText(); 
           contentStream.close();

           doc.save("C:/Users/VINAYAK/Desktop/docccc/break-long-string.pdf");
       }
       finally
       {
           if (doc != null)
           {
               doc.close();
           }
       }

   }  
}