leavedb.java

用java做的网上商店系统！代码完整。希望为大家有所帮助！

package org.qhit.shop.db;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class LeaveDB {
	//1.插入留言
	public int insert(LeaveBean l){
		//声明
		int i=0;
		Connection conn=null;
		PreparedStatement ps=null;
		String sql="insert into leave values(?,getdate(),?,?)";
		try {
			//1.连接
			conn=DBConn.getConn();
			//2.创建预编译指令集对象
			ps=conn.prepareStatement(sql);
			//3.绑定参数（和？对应的）
			ps.setString(1,l.getAuthor());
			ps.setString(2, l.getContents());
			ps.setInt(3, l.getGid());
			//4.执行
			i=ps.executeUpdate();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			try {
				if(ps!=null)ps.close();
				DBConn.close(conn);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}		
		return i;
	}
	//1.查询所有留言的方法
	public List queryAll(String gid){
		List all=new ArrayList();
		Connection conn=null;
		PreparedStatement ps=null;
		ResultSet rs=null;
		LeaveBean l=null;
		String sql="select * from leave where gid=? order by dt desc";
		try {
			//1.连接
			conn=DBConn.getConn();
			//2.创建预编译指令集对象
			ps=conn.prepareStatement(sql);			
			//4.执行
			ps.setInt(1, Integer.parseInt(gid));
			rs=ps.executeQuery();
			//遍历结果集，将数据封装到List中
			while(rs.next()){
				l=new LeaveBean();
				l.setId(rs.getInt(1));
				l.setAuthor(rs.getString(2));
				l.setDt(rs.getString(3).substring(0,19));
				l.setContents(rs.getString(4));
				l.setGid(rs.getInt(5));
				all.add(l);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			try {
				if(rs!=null)rs.close();
				if(ps!=null)ps.close();
				DBConn.close(conn);
			} catch (SQLException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		return all;
	}
}