Markdown转HTML

方式一：

依赖：

 <dependency>
     <groupId>org.pegdown</groupId>
     <artifactId>pegdown</artifactId>
     <version>1.6.0</version>
 </dependency>

生成案例

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

import org.pegdown.PegDownProcessor;

public class PageGenerator {

    public void generateHtml(File mdFile) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(mdFile), "UTF-8"));
        String line = null;
        String mdContent = "";
        while ((line = br.readLine()) != null) {
            mdContent += line + "\r\n";
        }
        PegDownProcessor pdp = new PegDownProcessor(Integer.MAX_VALUE);
        String htmlContent = pdp.markdownToHtml(mdContent);
        System.out.println(htmlContent);
    }


    public static void main(String[] args) throws IOException {
        PageGenerator pageGenerator = new PageGenerator();
        pageGenerator.generateHtml(new File("D:\\learning-blog\\后端\\Stream流妙用.md"));
    }

}

方式二：

依赖：

<!--   markdown 转 html   官网 https://github.com/commonmark/commonmark-java  -->
        <dependency>
            <groupId>com.atlassian.commonmark</groupId>
            <artifactId>commonmark</artifactId>
            <version>0.10.0</version>
        </dependency>
        <dependency>
            <groupId>com.atlassian.commonmark</groupId>
            <artifactId>commonmark-ext-heading-anchor</artifactId>
            <version>0.10.0</version>
        </dependency>
        <dependency>
            <groupId>com.atlassian.commonmark</groupId>
            <artifactId>commonmark-ext-gfm-tables</artifactId>
            <version>0.10.0</version>
        </dependency>

生成工具类

import org.commonmark.Extension;
import org.commonmark.ext.gfm.tables.TableBlock;
import org.commonmark.ext.gfm.tables.TablesExtension;
import org.commonmark.ext.heading.anchor.HeadingAnchorExtension;
import org.commonmark.node.Link;
import org.commonmark.node.Node;
import org.commonmark.parser.Parser;
import org.commonmark.renderer.html.AttributeProvider;
import org.commonmark.renderer.html.AttributeProviderContext;
import org.commonmark.renderer.html.AttributeProviderFactory;
import org.commonmark.renderer.html.HtmlRenderer;

import java.util.Arrays;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import java.util.List;
/**
 *   2021/11/25.
 */
public class MarkdownToHtmlUtils {

    /**
     * 增加扩展[标题锚点，表格生成]
     * Markdown转换成HTML
     * @param markdown
     * @return
     */
    public static String markdownToHtml(String markdown) {
        //h标题生成id
        Set<Extension> headingAnchorExtensions = Collections.singleton(HeadingAnchorExtension.create());
        //转换table的HTML
        List<Extension> tableExtension = Arrays.asList(TablesExtension.create());
        Parser parser = Parser.builder()
                .extensions(tableExtension)
                .build();
        Node document = parser.parse(markdown);
        HtmlRenderer renderer = HtmlRenderer.builder()
                .extensions(headingAnchorExtensions)
                .extensions(tableExtension)
                .attributeProviderFactory(new AttributeProviderFactory() {
                    @Override
                    public AttributeProvider create(AttributeProviderContext context) {
                        return new CustomAttributeProvider();
                    }
                })
                .build();
        return renderer.render(document);
    }

    /**
     * 处理标签的属性
     */
    static class CustomAttributeProvider implements AttributeProvider {
        @Override
        public void setAttributes(Node node, String tagName, Map<String, String> attributes) {
            //改变a标签的target属性为_blank
            if (node instanceof Link) {
                attributes.put("target", "_blank");
            }
            //给table标签的class属性值为 ui celled table
            if (node instanceof TableBlock) {
                attributes.put("class", "ui celled table");
            }
        }
    }

    /**
     * 测试
     * @param args
     */
    public static void main(String[] args) {
        String table = "| 1 | 2   | 3   |\n" +
                "| ----- | ---- | ----- |\n" +
                "| 22  | 22  | 22    |\n" +
                "| 阿什顿发  | 非固定杆 | 撒阿什顿发 |\n" +
                "\n";
        String a = "[fereli 爱编程](http://www.lirenmi.cn)";
       System.out.println(MarkdownToHtmlUtils.markdownToHtml(table));
       System.out.println(MarkdownToHtmlUtils.markdownToHtml(a));
    }

}

方式三：

依赖：

<!-- Markdown渲染 -->
        <dependency>
            <groupId>com.atlassian.commonmark</groupId>
            <artifactId>commonmark</artifactId>
            <version>0.12.1</version>
        </dependency>
        <dependency>
            <groupId>com.atlassian.commonmark</groupId>
            <artifactId>commonmark-ext-gfm-tables</artifactId>
            <version>0.12.1</version>
        </dependency>
        <dependency>
            <groupId>com.atlassian.commonmark</groupId>
            <artifactId>commonmark-ext-yaml-front-matter</artifactId>
            <version>0.12.1</version>
        </dependency>

生成工具类

package com.hshk.znhospital.care.utils;

import org.commonmark.Extension;
import org.commonmark.ext.front.matter.YamlFrontMatterExtension;
import org.commonmark.ext.gfm.tables.TableBlock;
import org.commonmark.ext.gfm.tables.TablesExtension;
import org.commonmark.node.Node;
import org.commonmark.parser.Parser;
import org.commonmark.renderer.html.AttributeProvider;
import org.commonmark.renderer.html.HtmlRenderer;

import java.util.Arrays;
import java.util.List;
import java.util.Map;

import java.util.Arrays;
import java.util.List;
import java.util.Map;

public class MarkdownUtils {
    /**
     * 插件
     */
    private static final List<Extension> EXTENSIONS = Arrays.asList(
            YamlFrontMatterExtension.create(),
            TablesExtension.create()
    );

    /**
     * 解析Markdown文档
     */
    private static final Parser PARSER = Parser.builder().extensions(EXTENSIONS).build();

    /**
     * 渲染HTML文档
     */
    private static final HtmlRenderer RENDERER = HtmlRenderer.builder().extensions(EXTENSIONS).attributeProviderFactory(context -> new BlogAttributeProvider()).build();

    /**
     * 渲染Markdown
     *
     * @param content content
     * @return String
     */
    public static String renderMarkdown(String content) {
        final Node document = PARSER.parse(content);
        return RENDERER.render(document);
    }

    static class BlogAttributeProvider implements AttributeProvider {

        @Override
        public void setAttributes(Node node, String s, Map<String, String> map) {
            if (node instanceof TableBlock) {
                map.put("class", "table table-bordered");
            }
        }
    }

    public static void main(String[] args) {
        String renderMarkdown = MarkdownUtils.renderMarkdown("var buttons = document.getElementsByClassName(\"next_button___YGZWZ\");");
        System.out.println("renderMarkdown = " + renderMarkdown);
    }
}