读本地文件demo方法

public String getFileString() throws Exception {
      String fileName = "C:\\Users\\fuli\\Desktop\\123.txt";
      File file = new File(fileName);
      StringBuilder sb = new StringBuilder();
      try ( FileInputStream fis = new FileInputStream(file);InputStreamReader isr = new InputStreamReader(fis, StandardCharsets.UTF_8)){
          BufferedReader bf = new BufferedReader(isr);
          String content ;
          while (true) {
              content = bf.readLine();
              if (content == null) {
                  break;
              }
              sb.append(content.trim());
          }
      }
      return sb.toString();
  }

引入org.apache.commons.io

{
  String fileName = "C:\\Users\\fuli\\Desktop\\123.txt";
  File file = new File(fileName);
  FileUtils.readFileToString(file, "utf-8")
}