一、读取json文件
直接读取文件，并转化为map
Ob

public static String readFile(String filePath) {
    StringBuffer stringBuffer = new StringBuffer("");
    byte[] buffer = new byte[1024];
    int count = 0;
    File file = new File(filePath);
    try {
        InputStream inputStream = new FileInputStream(file);
        while (-1 != (count = inputStream.read(buffer))) {
            stringBuffer.append(new String(buffer, 0, count));
        }
        inputStream.close();
    } catch (IOException ex) {
        ex.printStackTrace();
    }
    return stringBuffer.toString();
}

public static String readFile(String filePath) {
  String encoding = "UTF-8";
  File file = new File(filePath);
  Long filelength = file.length();
  byte[] filecontent = new byte[filelength.intValue()];
  try {
    FileInputStream in = new FileInputStream(file);
    in.read(filecontent);
    in.close();
  } catch (FileNotFoundException e) {
    e.printStackTrace();
  } catch (IOException e) {
    e.printStackTrace();
  }
  try {
    return new String(filecontent, encoding);
  } catch (UnsupportedEncodingException e) {
    System.err.println("The OS does not support " + encoding);
    e.printStackTrace();
    return null;
  }
}