项目打包成jar后包无法读取src/main/resources下文件的解决

String s = FileUtils.readFileToString(new File("src/main/resources/holiday.txt"), "utf-8");

    /**
     * 通过ClassPathResource类获取，建议SpringBoot中使用
     * springboot项目中需要使用此种方法，因为jar包中没有一个实际的路径存放文件
     *
     * @param fileName
     * @throws IOException
     */
    public void function6(String fileName) throws IOException {
        ClassPathResource classPathResource = new ClassPathResource(fileName);
        InputStream inputStream = classPathResource.getInputStream();
        getFileContent(inputStream);
    }

String s = FileUtils.readFileToString(new File("src/main/resources/holiday.txt"), "utf-8");

    /**
     * Java读取txt文件的内容
     *
     * @param fileName resources目录下文件名称(无需带目录)
     * @return 将每行作为一个单位放到list中
     */
    public static List<String> readTxtFile(String fileName) {
        List<String> listContent = new ArrayList<>();
        InputStream is = null;
        InputStreamReader isr = null;
        BufferedReader br = null;
        String encoding = "utf-8";
        try {
            Resource resource = new ClassPathResource(fileName);
            is = resource.getInputStream();
            isr = new InputStreamReader(is, encoding);
            br = new BufferedReader(isr);
            String lineTxt = null;
            while ((lineTxt = br.readLine()) != null) {
                listContent.add(lineTxt);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                br.close();
                isr.close();
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return listContent;
    }

  //方式二 利用FileUtils将ClassPathResource.getInputStream 得到的输入流复制到临时文件中
  Resource resource = new ClassPathResource("holiday.txt");
  InputStream inputStream = resource.getInputStream();
  File tempFile = File.createTempFile("temp", ".txt");
  FileUtils.copyInputStreamToFile(inputStream, tempFile);
  
  String s = FileUtils.readFileToString(tempFile, StandardCharsets.UTF_8);

	<!-- 资源拷贝插件，实现在打包时自动拷贝java目录下以及resources目录下的xml的配置文件 -->
		<resources>
			<resource>
				<directory>src/main/java</directory>
				<includes>
					<include>**/*.xml</include>
				</includes>
			</resource>
			<resource>
				<directory>src/main/resources</directory>
				<includes>
					<include>**/*.xml</include>
					<include>**/*.properties</include>
					<include>**/banner.txt</include>
				</includes>
			</resource>
		</resources>

	<!-- 资源拷贝插件，实现在打包时自动拷贝java目录下以及resources目录下的xml的配置文件 -->
		<resources>
			<resource>
				<directory>src/main/java</directory>
				<includes>
					<include>**/*.xml</include>
				</includes>
			</resource>
			<resource>
				<directory>src/main/resources</directory>
				<includes>
					<include>**/*.xml</include>
					<include>**/*.properties</include>
					<include>**/*.txt</include>
				</includes>
			</resource>
		</resources>