# 我是注釋
VERSION: '1.0'

# 我是注釋
FILE_NAME: foo

# 我是注釋
UNWIND:
  COUNT: 3
  UNWIND_CHECK: true
  
# 我是注釋
FLAGS:
  FLAG1: true
  FLAG2: false
  FLAG3: true
  FLAG4: true
  
 # 我是注釋
 DEFINES:
  - DEFINE1
  - DEFINE2
  - DEFINE3

# 我是注釋
VERSION: ${dumpHelper.settingBO.version!}

# 我是注釋
FILE_NAME: ${dumpHelper.settingBO.fileName!}

# 我是注釋
UNWIND: ${dumpHelper.getUnwind()!}

# 我是注釋
FLAGS: ${dumpHelper.getFlags()!}

# 我是注釋
DEFINES: ${dumpHelper.getDefines()!}

public class YamlGeneratorUtil {
    private static final Configuration freemarkerConfig;

    static {
        // 初始化Freemarker配置
        freemarkerConfig = new Configuration(Configuration.VERSION_2_3_0);
        freemarkerConfig.setClassForTemplateLoading(YamlGeneratorUtil.class, "/templates/");
    }

    /**
     * 根據(jù)模板生成單個yaml配置文件
     * @param templateName 模板名稱
     * @param outputFileName 生成的文件名
     * @param settingDumpHelper 配置轉儲輔助類
     */
    public static void generate(String templateName, String outputFileName, SettingDumpHelper settingDumpHelper) {
        try (FileWriter fileWriter = new FileWriter(outputFileName)) {
            Template template = freemarkerConfig.getTemplate(templateName);
            Map<String, Object> dataModel = new HashMap<>();
            dataModel.put("dumpHelper", freemarkerConfig.getObjectWrapper().wrap(settingDumpHelper));
            String config = FreeMarkerTemplateUtils.processTemplateIntoString(template, dataModel);
            fileWriter.write(config);
            System.out.println(config);
        } catch (IOException | TemplateException e) {
            throw new BusinessException(ErrorEnum.build(ErrorEnum.INTERNAL_SERVER_ERROR, "生成yaml文件失敗:" + e.toString()));
        }
    }
}

//示例：
DumperOptions dumperOptions = new DumperOptions();
// 指定流序列格式
dumperOptions.setDefaultFlowStyle(DumperOptions.FlowStyle.FLOW);
Yaml settingDumper = new Yaml(dumperOptions);
// 把數(shù)據(jù)轉換成yaml的流序列格式。
public String getFlags() {
       return settingDumper.dump(settingBO.getFlags());
}

YamlGeneratorUtil.generate("config.ftl", your_output_file, your_dump_helper);