readers.java~2~

图书管理系统,B/S,C/S都有,附有源代码

package reader;

import java.sql.*;
import java.util.Vector;
import database.*;
import book.bookInfo;
import javax.servlet.http.HttpServletRequest;

/**
 * <p>Title: library</p>
 * <p>Description: library</p>
 * <p>Copyright: Copyright (c) 2007</p>
 * <p>Company: </p>
 * @author nino
 * @version 0.1
 */

public class readers {
  public String createReaderSN() throws
      Exception {

    DataBase db = new DataBase();

    String newReaderSN = "0000000";
    int intReaderSN;
    try {
      //从数据库中取出最大的编号
      ResultSet rs = db.executeQuery("select max(读者编号) as 读者编号 from Book");
      rs.next();
      newReaderSN = rs.getString(1);
      //转换为INT格式以便增加
      intReaderSN = Integer.parseInt(newReaderSN);
      rs.close();
      //编号是否大于9999999
      if (intReaderSN < 9999999) {
        //编号+1
        intReaderSN++;
        //转换为字符串
        newReaderSN = Integer.toString(intReaderSN);
        //字符串不满7位前面填充0
        while (newReaderSN.length() < 7) {
          newReaderSN = "0" + newReaderSN;
        }
      }
      else {
        //编号大于9999999
        newReaderSN = "0000000";
      }
      return newReaderSN;
    }
    catch (SQLException e) {
      System.out.println(e);
      newReaderSN = "0000000";
    }
    return newReaderSN;
  }

}