/**
  * 构造函数
  *
  * @param s dbf文件的文件名
  * @throws JDBFException 文件没有找到时会抛出异常
  */
 public DBFReader(String s) throws JDBFException {
   stream = null;
   fields = null;
   nextRecord = null;
   nFieldCount = 0;
   try {
     init(new FileInputStream(s));
   } catch (FileNotFoundException filenotfoundexception) {
     throw new JDBFException(filenotfoundexception);
   }
 }
 /**
  * 使用inputstream来构造DBFReader
  *
  * @param inputstream 输入流
  * @throws JDBFException
  */
 public DBFReader(InputStream inputstream) throws JDBFException {
   stream = null;
   fields = null;
   nextRecord = null;
   init(inputstream);
 }