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。只显示其中的一部分。这也是一行。
我希望文本位于多行中。
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();
我的输出：
添加到 Mark 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。
把所有东西放在一起，你会得到这样的东西（根据 PDFBox 版本略有不同）：
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();
}
}
（PDFBox 1.8.x 的BreakLongString.java测试）testBreakString
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();
}
}
（针对 PDFBox 2.0.x 的BreakLongString.java测试）testBreakString
这看起来和预期的一样。
当然，还有很多改进要做，但这应该说明如何去做。
在评论中 aleskv 问道：
当字符串中有 \n 时，你可以添加换行符吗？
通过首先将字符串拆分为 '\n' 字符，然后迭代拆分结果，可以轻松地将解决方案扩展为在换行符处无条件中断。
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";
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...";
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)
{
[...]
}
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)
{
[...]
}
}
（来自BreakLongString.java测试testBreakStringNL）
结果：
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。
例如：“Lorem ipsum dolor sit 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
但它这样做：
Lorem ipsum dolor sit amet
我想出了我自己的解决方案，我想与你分享。
/**
* @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;
}
}
///// 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();
}
}
}
}
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;
}
这些是重要的行：
contentStream.beginText();
contentStream.moveTextPositionByAmount(textx,texty);
contentStream.drawString(text);
contentStream.endText();
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
contentStream.moveTextPositionByAmount(textx,texty) 是关键点。
例如，如果您使用的是 A4 尺寸，则意味着 580,800 是宽度和高度对应（大约）。因此您可以根据文档大小的位置移动文本。
PDFBox 支持多种页面格式。所以不同的页面格式的高度和宽度会有所不同
Pdfbox-layout抽象出管理布局的所有繁琐细节。作为一个完整的 Kotlin 示例，这里是如何将文本文件转换为 pdf 而无需担心换行和分页。
import org.apache.pdfbox.pdmodel.font.PDType1Font
import rst.pdfbox.layout.elements.Document
import rst.pdfbox.layout.elements.Paragraph
import java.io.File
fun main() {
val textFile = "input.txt"
val pdfFile = "output.pdf"
val font = PDType1Font.COURIER
val fontSize = 12f
val document = Document(40f, 50f, 40f, 60f)
val paragraph = Paragraph()
File(textFile).forEachLine {
paragraph.addText("$it\n", fontSize, font)
}
document.add(paragraph)
document.save(File(pdfFile))
}