其他的操作分别为增删改查的具体代码，分别对应Servlet中或jsp中需要实例化的代码，下面就是具体的DAO类代码：
package dao;
import com.lut.beans.NewsRealese;
import static java.lang.System.out;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
public class NewsRealeseDao {
public ArrayList queryAllNews() throws Exception {
Connection conn = null;
ArrayList newsRealese = new ArrayList();
try {
//获取连接
Class.forName("oracle.jdbc.driver.OracleDriver");
String url = "jdbc:oracle:thin:@localhost:1521:orcl";
conn = DriverManager.getConnection(url, "scott", "wjk139");
//运行SQL语句
String sql = "select * from newmessage";//获取
Statement stat = conn.createStatement();
ResultSet rs = stat.executeQuery(sql);
while (rs.next()) { //实例化VO
NewsRealese news = new NewsRealese();
news.setNewsId(rs.getString("newsid"));
news.setClassId(rs.getString("CLASSID"));
news.setKindId(rs.getString("KINDID"));
news.setMyOther(rs.getString("MYOTHER"));
news.setHeadTitle(rs.getString("HEADTITLE"));
news.setContent(rs.getString("CONTENT"));
news.setConnectRealtive(rs.getString("CONNECTREALTIVE"));
news.setAuthor(rs.getString("AUTHOR"));
news.setEditor(rs.getString("EDITOR"));
news.setNewsFrom(rs.getString("NEWSFROM"));
news.setTop(rs.getString("TOP"));
news.setNewsTime(rs.getString("NEWSTIME"));
news.setHits(rs.getString("HITS"));
news.setState(rs.getString("STATE"));
news.setTag(rs.getString("TAG"));
newsRealese.add(news);
}
rs.close();
stat.close();
} catch (Exception e1) {
e1.printStackTrace();
} finally {
try {//关闭连接
if (conn != null) {
conn.close();
conn = null;
}
} catch (Exception ex) {
}
return newsRealese;
}
}
//查询一个消息
public ArrayList queryOneNews(int newsid) throws Exception {
Connection conn = null;
ArrayList newsRealese = new ArrayList();
int temp_id = newsid;
try {
//获取连接
Class.forName("oracle.jdbc.driver.OracleDriver");
String url = "jdbc:oracle:thin:@localhost:1521:orcl";
conn = DriverManager.getConnection(url, "scott", "wjk139");//不安全
//运行SQL语句
Statement stat = conn.createStatement();
String sql = "select * from newmessage where newsid=?";//获取newsid，使用？代替字符串，以免会发生错误
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1, Integer.valueOf(newsid));
ResultSet rs = ps.executeQuery();// 之前已经给了sql字符串，所以executeUpdate是无参的。
while (rs.next()) { //实例化VO
NewsRealese news = new NewsRealese();
news.setNewsId(rs.getString("newsid"));
