HTML转PDF

2019-11-14 14:51:30

字体：大中小

来源：转载

供稿：网友

Maven依赖

<dependency>    <groupId>com.itextpdf</groupId>    <artifactId>itextpdf</artifactId>    <version>5.5.7</version></dependency><dependency>    <groupId>com.itextpdf.tool</groupId>    <artifactId>xmlworker</artifactId>    <version>5.5.7</version></dependency>

类图及API

IHtml2PdfService

HTML转PDF的服务接口

write (htmlContent: java.lang.String, os: java.io.OutputStream): void
将指定的html转换成pdf内容后，写到指定的输出流。

Html2PdfServiceImpl

HTML转PDF的服务实现类

write (htmlContent: java.lang.String, os: java.io.OutputStream): void
实现：将指定的html转换成pdf内容后，写到指定的输出流。
getIntaceHtml (htmlContent: String): String
私有方法，用于获取完整的html文档；如果传入的只是html片断，需要使用模板将其完整化。
doWrite (htmlContent: String, os: OutputStream): void
私有方法，将完整的html文档转换成pdf之后，写到指定的输出流。

代码

IHtml2PdfService

package cn.ljl.javaweb.demo.ckeditor.service;public interface IHtml2PdfService {    /** html完整内容的前缀标识 */    public static final String INTACT_FLAG = "<html>";        /**     * html模板，当待转换的html只是片断时，需将其插入到模板的body内.     */    public static final String TEMPLATE_HTML =             "<html>" +            "    <head>" +            "        <style type='text/CSS'>body {font-family: SimSun;}</style>" +            "    </head>" +            "    <body>" +            "        ${content}" +            "    </body>" +            "</html>";        /** 将指定的html内容转化成pdf文档之后，写入到指定的输出流. */    public void write(java.lang.String htmlContent, java.io.OutputStream os);    }

Html2PdfServiceImpl

package cn.ljl.javaweb.demo.ckeditor.service;import java.io.ByteArrayInputStream;import java.io.ByteArrayOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.nio.charset.Charset;import com.itextpdf.text.DocumentException;public class Html2PdfServiceImpl implements IHtml2PdfService {    @Override    public void write(String htmlContent, OutputStream os) {        if (htmlContent == null || htmlContent.length() == 0)            return;        if (os == null)            return;        htmlContent = getIntaceHtml(htmlContent);        doWrite(htmlContent, os);    }        /**     * 根据提供的html内容，获取完整的html内容.<br>     * @param htmlContent     * @return     */    PRivate String getIntaceHtml(String htmlContent) {        boolean intact = htmlContent.trim().toLowerCase()                .startsWith(INTACT_FLAG);        if (!intact) {            htmlContent = TEMPLATE_HTML.replaceFirst("//$//{content//}", htmlContent);        }        return htmlContent;    }        /**     * 实施写操作.<br>     * @param htmlContent     * @param os     */    private void doWrite(String htmlContent, OutputStream os) {        InputStream is = new ByteArrayInputStream(htmlContent.getBytes());        com.itextpdf.text.Document document = new com.itextpdf.text.Document();        com.itextpdf.text.pdf.PdfWriter writer = null;        try {            writer = com.itextpdf.text.pdf.PdfWriter                    .getInstance(document, os);            document.open();                        com.itextpdf.tool.xml.XMLWorkerHelper.getInstance().parseXHtml(writer,                    document, is, Charset.forName("gbk"));        } catch (DocumentException e) {            e.printStackTrace();        } catch (IOException e) {            e.printStackTrace();        }                writer.flush();        // SINOBEST HTML2PDF 如果我们调用writer.close()，可能无法正常的生成pdf，甚至会遇到        // Exception:The page 1 was requested but the document has only 0 pages.        // writer.close();        document.close();    }}