简述
目前网上已经有很多种html文件直接转pdf的技术帖子，但是很少有直接将部分html作为段落插入到pdf中，而且也没有一个可以很好的解决中文显示的问题。
因此今天上午围绕这个问题进行了研究，把解决方案分享给大家。
itextpdf基础操作请访问：http://www.cnblogs.com/mvilplss/p/5640598.html
感谢：http://gridmix.blog.51cto.com/4764051/1229585
实现思路
如果想插入html片段，我们使用一个类的静态方法：
1 String html = "<div style=‘color:green;font-size:20px;‘>你好世界！hello world !</div>";
2 Paragraph context = new Paragraph();
3 ElementList elementList =XMLWorkerHelper.parseToElementList(htmlString, null);
4 for (Element element : elementList) {
5 context.add(element);
6 }
7 document.add(context);
不过你会发现不能显示中文，这个问题网上有很多种解决方法，但是都不好使。
查看XMLWorkerHelper.parseToElementList(htmlString, null)这个方法的源码，发现
CssAppliers cssAppliers = new CssAppliersImpl(FontFactory.getFontImp());可以进行字体的更换。
1 public static ElementList parseToElementList(String html, String css) throws IOException {
2 // CSS
3 CSSResolver cssResolver = new StyleAttrCSSResolver();
4 if (css != null) {
5 CssFile cssFile = XMLWorkerHelper.getCSS(new ByteArrayInputStream(css.getBytes()));
6 cssResolver.addCss(cssFile);
7 }
8
9 // HTML
10 CssAppliers cssAppliers = new CssAppliersImpl(FontFactory.getFontImp());//这里可以下手对字体进行操作
11 HtmlPipelineContext htmlContext = new HtmlPipelineContext(cssAppliers);
12 htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());
13 htmlContext.autoBookmark(false);
14
15 // Pipelines
16 ElementList elements = new ElementList();
17 ElementHandlerPipeline end = new ElementHandlerPipeline(elements, null);
18 HtmlPipeline htmlPipeline = new HtmlPipeline(htmlContext, end);
19 CssResolverPipeline cssPipeline = new CssResolverPipeline(cssResolver, htmlPipeline);
20
21 // XML Worker
22 XMLWorker worker = new XMLWorker(cssPipeline, true);
23 XMLParser p = new XMLParser(worker);
24 p.parse(new ByteArrayInputStream(html.getBytes()));
25
26 return elements;
27 }
因此我们就想到重写XMLWorkerFontProvider类的getFont(*)方法，对于没有显示声明css样式的字体，默认使用undefine字体样式进行设置默认字体。
1 public class MyXMLWorkerHelper {
2 public static class MyFontsProvider extends XMLWorkerFontProvider {
3 public MyFontsProvider() {
4 super(null, null);
5 }
6
7 @Override
8 public Font getFont(final String fontname, String encoding, float size, final int style) {
9
10 String fntname = fontname;
11 if (fntname == null) {
12 fntname = "宋体";
13 }
14 return super.getFont(fntname, encoding, size, style);
15 }
16 }
17
18 public static ElementList parseToElementList(String html, String css) throws IOException {
19 // CSS
20 CSSResolver cssResolver = new StyleAttrCSSResolver();
21 if (css != null) {
22 CssFile cssFile = XMLWorkerHelper.getCSS(new ByteArrayInputStream(css.getBytes()));
23 cssResolver.addCss(cssFile);
24 }
25
26 // HTML
27 MyFontsProvider fontProvider = new MyFontsProvider();
28 CssAppliers cssAppliers = new CssAppliersImpl(fontProvider);
29 HtmlPipelineContext htmlContext = new HtmlPipelineContext(cssAppliers);
30 htmlContext.setTagFactory(Tags.getHtmlTagProcessorFactory());
31 htmlContext.autoBookmark(false);
32
33 // Pipelines
34 ElementList elements = new ElementList();
35 ElementHandlerPipeline end = new ElementHandlerPipeline(elements, null);
36 HtmlPipeline htmlPipeline = new HtmlPipeline(htmlContext, end);
37 CssResolverPipeline cssPipeline = new CssResolverPipeline(cssResolver, htmlPipeline);
38
39 // XML Worker
40 XMLWorker worker = new XMLWorker(cssPipeline, true);
41 XMLParser p = new XMLParser(worker);
42 html = html.replace("<br>", "").replace("<hr>", "").replace("<img>", "").replace("<param>", "")
43 .replace("<link>", "");
44 p.parse(new ByteArrayInputStream(html.getBytes()));
45
46 return elements;
47 }
48
49 }
因为XMLWork不支持html的单标签，所以要对但标签进行过滤。不然就会报错：Invalid nested tag div found, expected closing tag br
时间： 2024-10-12 01:24:13