一个web小项目04

package src.bean;

import java.sql.*;
import java.util.*;

/**
 * 构造BookInfo对象，对应数据库的BookInfo表 提供了多个静态方法完成BookInfo对象与对应数据库表的所有新增、查询、修改、删除等操作
 * 
 * @author Leiyu
 * @version 1.0
 *
 */
public class BookInfo {

   private String id;
   private String bookname;
   private String author;
   private String price;

   public String getBookname() {
      return bookname;
   }

   public void setBookname(String bookname) {
      this.bookname = bookname;
   }

   public String getAuthor() {
      return author;
   }

   public void setAuthor(String author) {
      this.author = author;
   }

   public String getPrice() {
      return price;
   }

   public void setPrice(String price) {
      this.price = price;
   }

   public void setId(String id) {
      this.id = id;
   }

   public String getId() {
      return id;
   }

   /**
    * 从BookInfo表中获取所有的图书信息
    * 
    * @return BookInfo的数组
    */
   public static ArrayList<BookInfo> getBookList() {
      ArrayList<BookInfo> list = new ArrayList<BookInfo>();
      String sql = "select * from bookinfo";
      src.bean.DBBean jdbc = new src.bean.DBBean();
      ResultSet rs = jdbc.executeQuery(sql);
      try {
         while (rs.next()) {
            BookInfo bi = new BookInfo();
            bi.setId(rs.getString("id"));
            bi.setBookname(rs.getString("bookname"));
            bi.setAuthor(rs.getString("author"));
            bi.setPrice(rs.getString("price"));
            list.add(bi);
         }
         rs.close();
      } catch (SQLException e) {
         e.printStackTrace();
      }
      jdbc.close();
      return list;
   }

   /**
    * 获取指定id的图书信息
    * 
    * @param id 图书id
    * @return 一个BookInfo对象
    */
   public static BookInfo getBookById(String id) {
      String sql = "select * from bookinfo where id=" + id;
      src.bean.DBBean jdbc = new src.bean.DBBean();
      ResultSet rs = jdbc.executeQuery(sql);
      BookInfo bi = new BookInfo();
      try {
         if (rs.next()) {
            bi.setId(rs.getString("id"));
            bi.setBookname(rs.getString("bookname"));
            bi.setAuthor(rs.getString("author"));
            bi.setPrice(rs.getString("price"));
         }
         rs.close();
      } catch (SQLException e) {
         e.printStackTrace();
      }
      jdbc.close();
      return bi;
   }

   /**
    * 更新指定id的图书信息
    * 
    * @param bi       要更新的图书的对象
    * @return 修改的结果：1代表成功，0代表没有更新
    */
   public static int updateBook(BookInfo bi) {
      int result = 0;
      String sql = "update bookinfo set bookname='" + bi.getBookname() + "',author='" + bi.getAuthor() + "',price="
            + bi.getPrice() + " where id=" + bi.getId();
      src.bean.DBBean jdbc = new src.bean.DBBean();
      result = jdbc.executeUpdate(sql);
      jdbc.close();
      return result;
   }

   /**
    * 删除指定id的图书
    * 
    * @param id 图书id
    * @return 删除的结果：1代表成功，0代表没有删除
    */
   public static int deleteBook(String id) {
      int result = 0;
      String sql = "delete from bookinfo where id=" + id;
      src.bean.DBBean jdbc = new src.bean.DBBean();
      result = jdbc.executeUpdate(sql);
      jdbc.close();
      return result;
   }

   /**
    * 增加一本图书
    * 
    * @param bi 图书对象
    * @return 新增的结果：1代表成功，0代表没有增加
    */
   public static int addBook(BookInfo bi) {
      int result = 0;
      String sql = "insert into bookinfo values(null,'" + bi.getBookname() + "','" + bi.getAuthor() + "',"
            + bi.getPrice() + ")";
      src.bean.DBBean jdbc = new src.bean.DBBean();
      result = jdbc.executeUpdate(sql);
      jdbc.close();
      return result;
   }
}

package src.bean;

import java.sql.*;

/**
 * 完成与数据库的连接和数据的访问
 * @author Leiyu
 * @version 1.0
 *
 */
public class DBBean {
   private String driverStr = "com.mysql.jdbc.Driver";
   private String connStr = "jdbc:mysql://127.0.0.1:3306/db?useSSL=false&useUnicode=true&characterEncoding=utf-8";
   private String dbusername = "root";
   private String dbpassword = "libin1214";
   private Connection conn = null;
   private Statement stmt = null;

   public DBBean() {
      try {
         Class.forName(driverStr);
         conn = DriverManager.getConnection(connStr, dbusername, dbpassword);
         stmt = conn.createStatement();
      } catch (Exception ex) {
         System.out.println("数据库连接失败！");
      }
   }

   /**
    * 执行更新操作
    * @param s
    * SQL语句
    * @return
    * 更新操作的结果
    */
   public int executeUpdate(String s) {
      int result = 0;
      try {
         result = stmt.executeUpdate(s);
      } catch (Exception ex) {
         System.out.println("更新出现异常！");
      }
      return result;
   }
   
   /**
    * 执行查询操作
    * @param s
    * SQL语句
    * @return
    * 查询结果
    */
   public ResultSet executeQuery(String s) {
      ResultSet rs = null;
      try {
         rs = stmt.executeQuery(s);
      } catch (Exception ex) {
         System.out.println("查询出现异常！");
      }
      return rs;
   }

   /**
    * 关闭数据库
    */
   public void close() {
      try {
         stmt.close();
         conn.close();
      } catch (Exception e) {
      }
   }
}

标签：web,return,String,04,项目,rs,bi,public,id
来源： https://www.cnblogs.com/libin159/p/16373030.html