HexoFrontMatterBatchProcess.java

package com.haoyizebo;

import org.yaml.snakeyaml.DumperOptions;
import org.yaml.snakeyaml.Yaml;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.text.SimpleDateFormat;
import java.util.*;

/**
 * <p>
 * 去除 hexo front matter 里无用的 permalink 和 id
 * <p>
 * 并根据文件名添加 addrlink
 * <p>
 * dependency: <a href="https://mvnrepository.com/artifact/org.yaml/snakeyaml">SnakeYAML</a>
 *
 * @author yibo
 */
public class HexoFrontMatterBatchProcess {

    public static void main(String[] args) throws IOException {
        // 设置 yaml 输出格式
        DumperOptions options = new DumperOptions();
        options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
        options.setPrettyFlow(true);
        options.setIndent(4);
        options.setIndicatorIndent(2);
        options.setTimeZone(TimeZone.getTimeZone("+8"));
        Yaml yaml = new Yaml(options);

        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

        File postDir = new File("/Users/yibo/hexo-blog/source/_posts");
        for (File file : Objects.requireNonNull(postDir.listFiles())) {
            String fileName = file.getName();

            if (fileName.equals(".DS_Store")) {
                continue;
            }

            // 文件名示例 2016-01-03-golang-note-1.md
            String title = fileName.substring(11, fileName.length() - 3);

            List<String> lines = Files.readAllLines(file.toPath(), StandardCharsets.UTF_8);

            // 第一行是 --- 忽略
            int lineNum = 1;
            // 获取 front matter
            StringBuilder frontMatterBuilder = new StringBuilder();
            while (true) {
                String line = lines.get(lineNum);
                if (line.trim().equals("---")) {
                    break;
                }
                lineNum++;
                frontMatterBuilder.append(line).append("\n");
            }

            // 处理 front matter
            Map<String, Object> frontMatterMap = yaml.load(frontMatterBuilder.toString());
            frontMatterMap.remove("id");
            frontMatterMap.remove("permalink");
            frontMatterMap.put("addrlink", title);
            // 需要将 Date 转为 String，否则默认的格式不对
            Object date = frontMatterMap.get("date");
            if (date instanceof Date) {
                frontMatterMap.put("date", sdf.format(date));
            }
            String frontMatter = yaml.dump(frontMatterMap);

            // 正文内容
            String content = String.join("\n", lines.subList(lineNum + 1, lines.size()));

            //
            String post = "---\n" +
                    frontMatter +
                    "---\n" +
                    content;

            Files.write(file.toPath(), post.getBytes());

        }

    }

}