这是一个简单的读取文件内容的方法：

  public String readFile(String fileName) throws Exception {
    String fileContent = "";
    File f = new File(fileName);
    FileReader fileReader = new FileReader(f);
    BufferedReader reader = new BufferedReader(fileReader);
    String line = "";
    while (line = reader.readLine() != null) {
      String fileContent = fileContent + line;
    }
    reader.close();
    return fileContent;
  }