code: public static PrintWriter getPrintWriter(String path, String charset, boolean isAppend) throws IORuntimeException {
  		return new PrintWriter(getWriter(path, charset, isAppend));
  	}
docs: 获得一个打印写入对象，可以有print
  
  @param path 输出路径，绝对路径
  @param charset 字符集
  @param isAppend 是否追加
  @return 打印对象
  @throws IORuntimeException IO异常