readguestbook.java

采用jsp+servlet+javabean

package guestbook;

import java.sql.*;
import javax.sql.DataSource;

public class ReadGuestbook{
  private int id;
  private String username =null;
  private String userqq=null;
  private String useremail=null;
  private String content = null;
  private String reply =null;
  private String writetime = null;
  private String replytime = null;
  private boolean flag;
  private int rowCount;
  private Statement stmt=null;
  private Connection conn=null;
  private ResultSet rs=null;
  private DataSource dataSource=null;
  //构造函数初始化ResultSet
  public ReadGuestbook(String path){
    Init init=new Init(path);
    dataSource=LinkDB.getDB();
    if (dataSource==null) {
      LinkDB.setDB(init.getDriverName(),init.getDBURL(),init.getDBUser(),init.getDBPassword());
      dataSource=LinkDB.getDB();
    }
    try{
        conn = dataSource.getConnection();
        stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
        rs = stmt.executeQuery("select * from guestbook");
        flag = rs.last();
        rowCount=rs.getRow();
    }
    catch(SQLException e){
      throw new RuntimeException(e);
    }
  }
  //读取pointPosition设置的指针下的数据
  public void readSQL(int pointPosition){
    try{
      if(flag&&rs.absolute(pointPosition)){
        id=rs.getInt("id");
        username = rs.getString("name").trim();
        userqq = rs.getString("qq").trim();
        useremail = rs.getString("email").trim();
        reply = rs.getString("reply").trim();
        replytime = rs.getString("replytime").trim();
        content = rs.getString("note").trim();
        writetime = rs.getString("writetime").trim();
        flag = rs.next();//判断记录集是否结束
        if(!flag) close();//记录集结束就关闭连接
      }
    }
    catch(SQLException e){
      throw new RuntimeException(e);
    }
  }
  public int getID(){
    return id;
  }
  public String getUsername(){
    if(username==null) return "";
    else return username;
  }
  public String getUserqq(){
    if(userqq==null) return "";
    else return userqq;
  }
  public String getUseremail(){
    if(useremail==null) return "";
    else return useremail;
  }
  public String getContent(){
    if(content==null) return "";
    else return content;
  }
  public String getReply(){
    if(reply==null) return "";
    else return reply;
  }
  public String getWritetime(){
    if(writetime==null) return "";
    else return writetime;
  }
  public String getReplytime(){
    if(replytime==null) return "";
    else return replytime;
  }
  public boolean isEnd(){
    return flag;
  }
  public int getRowcount(){
    return rowCount;
  }
  public void close(){
    try {
      rs.close();
      stmt.close();
      conn.close();
      LinkDB.shutdownDataSource(dataSource);
    }
    catch (SQLException e) {
      throw new RuntimeException(e);
    }
  }
}