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for example!
iText是用于生成PDF文档的一个java类库，通过iText不仅可以生成PDF或rtf的文档，而且还可以将XML、Html文件转化为PDF文件。
<dependencies>
<!-- pdf:start -->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itextpdf</artifactId>
<version>5.5.11</version>
</dependency>
<dependency>
<groupId>com.itextpdf.tool</groupId>
<artifactId>xmlworker</artifactId>
<version>5.5.11</version>
</dependency>
<!-- 支持中文 -->
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itext-asian</artifactId>
<version>5.2.0</version>
</dependency>
<!-- 支持css样式渲染 -->
<dependency>
<groupId>org.xhtmlrenderer</groupId>
<artifactId>flying-saucer-pdf-itext5</artifactId>
<version>9.1.16</version>
</dependency>
<!-- 转换html为标准xhtml包 -->
<dependency>
<groupId>net.sf.jtidy</groupId>
<artifactId>jtidy</artifactId>
<version>r938</version>
</dependency>
<!-- pdf:end -->
</dependencies>我们先来一个简单的test：
public class CreatePDFMainTest {
public static void main(String[] args) throws Exception {
Document document = new Document(PageSize.A4);
//第二步，创建Writer实例
PdfWriter.getInstance(document, new FileOutputStream("hello.pdf"));
//创建中文字体
BaseFont bfchinese = BaseFont.createFont("STSong-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
Font fontChinese = new Font(bfchinese, 12, Font.NORMAL);
//第三步，打开文档
document.open();
//第四步，写入内容
Paragraph paragraph = new Paragraph("hello world", fontChinese);
document.add(paragraph);
//第五步，关闭文档
document.close();
}
}
在实际的业务开发中，我们经常会采用HTML文件转化为PDF文件。
首先，我们采用html语言编写一个入库单页面，将其命令为printDemo.html，源代码如下：
<html>
<head></head>
<body>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>出库单</title>
<div>
<div>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tbody>
<tr>
<td height="40" colspan="2"><h3 style="font-weight: bold; text-align: center; letter-spacing: 5px; font-size: 24px;">入库单</h3></td>
<td width="12%" height="20" rowspan="2">
<img style="width: 105px;height: 105px;" src="data:image/jpeg;base64,iVBORw0KGgoAAAANSUhEUgAAAH0AAAB9AQAAAACn+1GIAAAAqElEQVR42u3VMQ7DMAwDQP6A//8lx24qKRRw0s1yu8Uw4OQGIaHsBHUfLzzwAxCAInoZg6dI9dUUBIOyHEG56CmodAaxwtfbboLTVWpeU9+EDAH37m9CmkTYxDGUE0agMIakk3y4Ut8G37iom02M4bPniHWAtqFDTjjSGLrZvXAOmTnL1124C73r6Yo8Ane61k6eQeVjIM2h482D1RwScrpNjuH5R/0b3s6ZZNyKlt3iAAAAAElFTkSuQmCC" />
</td>
</tr>
<tr>
<td width="50%" height="30">操作人：xxx</td>
<td width="50%" height="30" colspan="2">创建时间：2021-09-14 12:00:00</td>
</tr>
</tbody>
</table>
</div>
<div style="margin-top: 5px; margin-bottom: 6px; margin-left: 4px"></div>
<div>
<table width="100%"
style="border-collapse: collapse; border-spacing: 0;border:0px;">
<tr style="height: 25px;">
<td style="background: #eaeaea; text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;"
width="10%">序号</td>
<td style="background: #eaeaea; text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;"
width="30%">商品</td>
<td style="background: #eaeaea; text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;"
width="30%">单位</td>
<td style="background: #eaeaea; text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-right: 1px solid #000000;"
width="30%">数量</td>
</tr>
<tr>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">1</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">xxx沐浴露</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">箱</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-right: 1px solid #000000;">3</td>
</tr>
<tr>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">2</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">xxx洗发水</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">箱</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-right: 1px solid #000000;">4</td>
</tr>
<tr>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">3</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">xxx洗衣粉</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000;">箱</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-right: 1px solid #000000;">5</td>
</tr>
<tr>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-bottom: 1px solid #000000;">4</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-bottom: 1px solid #000000;">xxx洗面奶</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-bottom: 1px solid #000000;">箱</td>
<td style="text-align: center; border-left: 1px solid #000000; border-top: 1px solid #000000; border-right: 1px solid #000000; border-bottom: 1px solid #000000;">5</td>
</tr>
</table>
</div>
</div>
</body>
</html>接着，我们将html文件转成PDF文件，源码如下：
public class CreatePDFMainTest {
/**
* 创建PDF文件
* @param htmlStr
* @throws Exception
*/
private static void writeToOutputStreamAsPDF(String htmlStr) throws Exception {
String targetFile = "pdfDemo.pdf";
File targeFile = new File(targetFile);
if(targeFile.exists()) {
targeFile.delete();
}
//定义pdf文件尺寸，采用A4横切
Document document = new Document(PageSize.A4, 25, 25, 15, 40);// 左、右、上、下间距
//定义输出路径
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(targetFile));
PdfReportHeaderFooter header = new PdfReportHeaderFooter("", 8, PageSize.A4);
writer.setPageEvent(header);
writer.addViewerPreference(PdfName.PRINTSCALING, PdfName.NONE);
document.open();
// CSS
CSSResolver cssResolver = new StyleAttrCSSResolver();
CssAppliers cssAppliers = new CssAppliersImpl(new XMLWorkerFontProvider(){
@Override
public Font getFont(String fontname, String encoding, boolean embedded, float size, int style, BaseColor color) {
try {
//用于中文显示的Provider
BaseFont bfChinese = BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
returnnew Font(bfChinese, size, style);
} catch (Exception e) {
returnsuper.getFont(fontname, encoding, size, style);
}
}
});
//html
HtmlPipelineContext htmlContext = new HtmlPipelineContext(cssAppliers);
htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());
htmlContext.setImageProvider(new AbstractImageProvider() {
@Override
public Image retrieve(String src) {
//支持图片显示
int pos = src.indexOf("base64,");
try {
if (src.startsWith("data") && pos > 0) {
byte[] img = Base64.decode(src.substring(pos + 7));
return Image.getInstance(img);
} elseif (src.startsWith("http")) {
return Image.getInstance(src);
}
} catch (BadElementException ex) {
returnnull;
} catch (IOException ex) {
returnnull;
}
returnnull;
}
@Override
public String getImageRootPath() {
returnnull;
}
});
// Pipelines
PdfWriterPipeline pdf = new PdfWriterPipeline(document, writer);
HtmlPipeline html = new HtmlPipeline(htmlContext, pdf);
CssResolverPipeline css = new CssResolverPipeline(cssResolver, html);
// XML Worker
XMLWorker worker = new XMLWorker(css, true);
XMLParser p = new XMLParser(worker);
p.parse(new ByteArrayInputStream(htmlStr.getBytes()));
document.close();
}
/**
* 读取 HTML 文件
* @return
*/
private static String readHtmlFile() {
StringBuffer textHtml = new StringBuffer();
try {
File file = new File("printDemo.html");
BufferedReader reader = new BufferedReader(new FileReader(file));
String tempString = null;
// 一次读入一行，直到读入null为文件结束
while ((tempString = reader.readLine()) != null) {
textHtml.append(tempString);
}
reader.close();
} catch (IOException e) {
returnnull;
}
return textHtml.toString();
}
public static void main(String[] args) throws Exception {
//读取html文件
String htmlStr = readHtmlFile();
//将html文件转成PDF
writeToOutputStreamAsPDF(htmlStr);
}
}运行程序，打开pdfDemo.pdf，结果如下！
2.4、变量替换方式
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<div>您好：${name}</div>
<div>欢迎，登录博客网站</div>
</body>
</html>itext框架是一个非常实用的第三方pdf文件生成库，尤其是面对比较简单的pdf文件内容渲染的时候，它完全满足我们的需求。
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