1.添加依赖

      <!--解决中文显示问题-->
    <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itext-asian</artifactId>
            <version>5.2.0</version>
        </dependency>
  <!--生成html代码-->
        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.11.2</version>
        </dependency>
      <!--生成pdf-->
        <dependency>
            <groupId>com.itextpdf</groupId>
            <artifactId>itextpdf</artifactId>
            <version>5.5.13</version>
        </dependency>
        <!--xml模板-->
        <dependency>
            <groupId>com.itextpdf.tool</groupId>
            <artifactId>xmlworker</artifactId>
            <version>5.5.13</version>
        </dependency>

2.生成pdf在页面预览

@RequestMapping("/showPdf")
    public void showPdf(HttpServletResponse response){
        try {
            response.setContentType("application/pdf");
            //inline设置是强制浏览器显示，attachment设置时强制浏览器下载
            response.setHeader("Content-Disposition", "inline; filename= file");
            // 1.新建document
            Document document = new Document();
            // 2.建立一个书写器(Writer)与document对象关联，通过书写器(Writer)可以将文档写入到磁盘中。
            //创建 PdfWriter 对象 第一个参数是对文档对象的引用，第二个参数是文件的实际名称，在该名称中还会给出其输出路径。
            PdfWriter writer = PdfWriter.getInstance(document, response.getOutputStream());
            // 3.打开文档
            document.open();
            //要解析的html
            //html转换成普通文字,方法如下:
            org.jsoup.nodes.Document  contentDoc = Jsoup.parseBodyFragment("<h1 align=\"center\">" + "测试主题"+ "</h1>");
            org.jsoup.nodes.Document.OutputSettings outputSettings = new org.jsoup.nodes.Document.OutputSettings();
            outputSettings.syntax(org.jsoup.nodes.Document.OutputSettings.Syntax.xml);
            contentDoc.outputSettings(outputSettings);
            String parsedHtml = contentDoc.outerHtml();
            System.out.println(parsedHtml);
            //这儿的font-family不支持汉字，{font-family:仿宋} 是不可以的。
            InputStream cssIs = new ByteArrayInputStream("* {font-family: PingFang-SC-Medium.otf;}".getBytes("UTF-8"));
            //第四个参数是html中的css文件的输入流
            //第五个参数是字体提供者，使用系统默认支持的字体时，可以不传。
            Charset charset = Charset.defaultCharset();
            XMLWorkerHelper.getInstance().parseXHtml(writer, document,  new ByteArrayInputStream(parsedHtml.getBytes()), null,charset,new FontProviderUtil());

            // XMLWorkerHelper.getInstance().parseXHtml(writer, document, new ByteArrayInputStream(parsedHtml.getBytes()));
            // 5.关闭文档
            document.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

3.中文显示问题

重写XMLWorkerFontProvider类

public class FontProviderUtil extends XMLWorkerFontProvider {
    @Override
    public Font getFont(final String fontname, final String encoding,
                        final boolean embedded, final float size, final int style,
                        final BaseColor color) {
        BaseFont bf = null;
        try {
            bf = BaseFont.createFont("STSongStd-Light", "UniGB-UCS2-H", BaseFont.NOT_EMBEDDED);
        } catch (Exception e) {
            e.printStackTrace();
        }
        Font font = new Font(bf, size, style, color);
        font.setColor(color);
        return font;
    }
}

4.替换字符串中的${xxx}特殊字符

重写mybatis替换占位符的方法去实现

// 重写mybatis中解决占位符替换问题
public class VariableTokenHandler implements TokenHandler {
    private Map<String, String> variables = new HashMap<>();
    public VariableTokenHandler(Map<String, String> variables) {
        this.variables = variables;
    }
    @Override
    public String handleToken(String content) {
        String value = variables.get(content);
            return value ;
    }
}

5.调用

 Map<String,String> params = new HashMap<>() ;
        params.put("name","zzp") ;
        params.put("age","25") ;
        String sqlTemplate = "123insert into user(username,age,sequence,${age}) values(${name},${age},${name}.nextval)" ;
        VariableTokenHandler handler = new VariableTokenHandler(params);
        // 替换sql模板中的${xxx}占位符
        GenericTokenParser parser = new GenericTokenParser("${", "}", handler);
        String retContent = parser.parse(sqlTemplate);
        System.out.println(retContent);

6.问题

生成的富文本xml中,出现替换不了的占位符，可能是占位符不对,如:${name}变成了${name<u></u>}