7.html占位符替换

1.技术freemarker

代码 https://gitee.com/J-summit/note-sty-blogs/tree/master/src/main/java/tech/cn/note/html

image.png
参考https://www.cnblogs.com/itdragon/p/7750903.html
http://freemarker.foofun.cn/index.html

2.代码实现

@Service
public class FreeMakerDataFillServiceImpl implements FreeMakerDataFillService {

    private final List<DocumentConvert> convertList;

    @Autowired
    public FreeMakerDataFillServiceImpl(List<DocumentConvert> convertList) {
        this.convertList = convertList;
    }

    @Override
    public byte[] processToByte(File templateFile, Map<String, Object> dataSource) {
        return doProcess(templateFile.getParent(), templateFile.getName(), dataSource);
    }

    @Override
    public byte[] processToByte(String templatePath, Map<String, Object> dataSource) {
        File templateFile = checkTemplateFile(templatePath);
        return doProcess(templateFile.getParent(), templateFile.getName(), dataSource);
    }

    @Override
    public byte[] processToByte(String templateDir, String templateName, Map<String, Object> dataSource) {
        checkTemplateFile(templateDir, templateName);
        return doProcess(templateDir, templateName, dataSource);
    }

    @Override
    public ByteArrayInputStream processToStream(File templateFile, Map<String, Object> dataSource) {
        byte[] outBytes = processToByte(templateFile, dataSource);
        if (outBytes == null || outBytes.length < 1) {return null;}
        //转换为字节流
        return new ByteArrayInputStream(outBytes);
    }

    @Override
    public ByteArrayInputStream processToStream(String templatePath, Map<String, Object> dataSource) {
        byte[] outBytes = processToByte(templatePath, dataSource);
        if (outBytes == null || outBytes.length < 1){ return null;}
        //转换为字节流
        return new ByteArrayInputStream(outBytes);
    }

    @Override
    public ByteArrayInputStream processToStream(String templateDir, String templateName, Map<String, Object> dataSource) {
        byte[] outBytes = processToByte(templateDir, templateName, dataSource);
        if (outBytes == null || outBytes.length < 1) {return null;}
        //转换为字节流
        return new ByteArrayInputStream(outBytes);
    }


    /**
     * 填充数据至模板中
     */
    private byte[] doProcess(String templateDir, String templateName, Map<String, Object> dataSource) {
        DocumentConfiguration fillConfig;
        StringWriter outWriter;
        try {
            log.debug("模板名称:{},填充数据开始,data is {}", templateName, JSONUtil.parse(dataSource));
            //填充数据转换自定义方法
            if (CollUtil.isNotEmpty(convertList)) {
                convertList.forEach(c -> dataSource.put(c.getConvertName(), c));
            }
            //根据模板目录获取对象
            fillConfig = new DocumentConfiguration(templateDir);
            outWriter = new StringWriter();
            //获取模板对象
            Template template = fillConfig.getTemplate(templateName);
            //填充数据至模板中
            template.process(dataSource, outWriter);
            log.info("模板名称:{},填充数据结束...", templateName);
            return outWriter.toString().getBytes(StandardCharsets.UTF_8);
        } catch (Exception e) {
            String msg = String.format("填充模板数据出错, 模板名称:%1s", templateName);

            log.error(msg + ", 出错信息: " + e);
            throw new RuntimeException(msg);
        }
    }


    /**
     * 检查模板路径
     */
    private File checkTemplateFile(String templatePath) {
        if (StringUtils.isBlank(templatePath)) {
            throw new RuntimeException("数据填充模板路径不允许为空");
        }
        File templateFile = new File(templatePath);
        if (!templateFile.exists()) {
            throw new RuntimeException("数据填充模板文件不存在");
        }
        return templateFile;
    }

    /**
     * 检查模板路径
     */
    private File checkTemplateFile(String templateDir, String templateName) {
        if (StringUtils.isBlank(templateDir)) {
            throw new RuntimeException("数据填充模板目录不允许为空");
        }
        if (StringUtils.isBlank(templateName)) {
            throw new RuntimeException("数据填充模板名称不允许为空");
        }
        String templatePath = String.format("%1s%2s%3s", templateDir, File.separator, templateName);
        File templateFile = new File(templatePath);
        if (!templateFile.exists()) {
            throw new RuntimeException("数据填充模板文件不存在");
        }
        return templateFile;
    }
}