newsdao.java

一个用自己写的新闻系统(Struts) ,比较简单

package com.weipure.struts.dao;

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

import com.weipure.struts.form.LogonForm;
import com.weipure.struts.form.NewsForm;
import com.weipure.struts.tool.DBConnection;

public class NewsDAO {
	private DBConnection dbc = new DBConnection();

	public List queryAll() {
        String sql = "select * from news order by newsid"; 
        List list = new ArrayList();
        ResultSet rs = dbc.executeQuery(sql);
        if (rs != null) {
            try {
                while (rs.next()) {
                    NewsForm model = new NewsForm();
 					model.setId(rs.getString("newsid"));
                    model.setTitle(rs.getString("title"));
                    model.setCreatedate(rs.getString("createdate"));
                    model.setContent(rs.getString("content"));
                    list.add(model);
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        dbc.close();
        return list;
    }
	
	public int add(NewsForm nf) {
		int num = 0;
		String sql = "insert into news(newsid,title,content,createdate) values('"
			+ nf.getId() + "','" + nf.getTitle() + "','" +nf.getContent() + "','"
			+ nf.getCreatedate() + "')";
		num = dbc.executeUpdate(sql);
		dbc.close();
		return num;
	}
	
	public int del(String id) {
		int num = 0;
		String sql = "delete from news where newsid ='"+id+"'";
		num = dbc.executeUpdate(sql);
		dbc.close();
		return num;
	}

	public List query(String sql) {
		List list = new ArrayList();
		ResultSet rs = dbc.executeQuery(sql);
		try {
			while(rs.next()){
				NewsForm model = new NewsForm();
				model.setId(rs.getString("newsid"));
                model.setTitle(rs.getString("title"));
                model.setCreatedate(rs.getString("createdate"));
                model.setContent(rs.getString("content"));
                list.add(model);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;
	}

	public int modify(NewsForm nf, String id) {
		int num = 0;
		String sql = "update news set title = '"+nf.getTitle()+"',content = '"+nf.getContent()+"',createdate = '"+nf.getCreatedate()+"' where newsid = "+nf.getId();
		num = dbc.executeUpdate(sql);
		dbc.close();
		return num;
	}

}