accessforumdao.java

又一个课程设计 简易 JSP 论坛 功能较简单的那种, 界面上模仿了 Discuz JSP 本来就学的不行, 只是尽量实现了 MVC

package cn.ialvin.bbs.dao;

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

import cn.ialvin.bbs.bean.Forum;
import cn.ialvin.sql.DBConnection;

public class AccessForumDAO implements IForumDAO {
	private DBConnection coxn;
	AccessForumDAO(DBConnection coxn) { this.coxn = coxn; }
	public boolean deleteForum(int id) {
		boolean res = false;
		String sql = "DELETE FROM  [forum] WHERE [id]=?";
		PreparedStatement stmt = null;
		try {
			stmt = this.coxn.prepareStatement(sql);
			stmt.setInt(1, id);
			stmt.execute();
			res = true;
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			this.coxn.closeStatement(stmt);
		}
		return res;
	}
	public Forum getForum(int id) {
		Forum forum = null;
		String sql = "SELECT * FROM [forum] WHERE [id]=" + id;
		PreparedStatement stmt = null;
		ResultSet rs = null;
		try {
			stmt = this.coxn.prepareStatement(sql);
			rs = stmt.executeQuery();
			if (rs.next()) {
				forum = new Forum();
				forum.setId(rs.getInt("id"));
				forum.setName(rs.getString("name"));
				forum.setDescription(rs.getString("descripted"));
				forum.setTopic(rs.getInt("topic"));
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			this.coxn.closeResultSet(rs);
			this.coxn.closeStatement(stmt);
		}
		return forum;
	}
	public ArrayList<Forum> getForums() {
		ArrayList<Forum> list = new ArrayList<Forum>();
		String sql = "SELECT * FROM [forum]";
		PreparedStatement stmt = null;
		ResultSet rs = null;
		try {
			stmt = this.coxn.prepareStatement(sql);
			rs = stmt.executeQuery();
			while (rs.next()) {
				Forum forum = new Forum();
				forum.setId(rs.getInt("id"));
				forum.setName(rs.getString("name"));
				forum.setDescription(rs.getString("descripted"));
				forum.setTopic(rs.getInt("topic"));
				list.add(forum);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			this.coxn.closeResultSet(rs);
			this.coxn.closeStatement(stmt);
		}
		return list;
	}
	public int insertForum(Forum forum) {
		int res = -1;
		String sql = "INSERT INTO [forum] ([name], [descripted], [topic]) " +
				"VALUES(?, ?, 0)";
		PreparedStatement stmt = null;
		ResultSet rs = null;
		try {
			stmt = this.coxn.prepareStatement(sql);
			stmt.setString(1, forum.getName());
			stmt.setString(2, forum.getDescription());
			stmt.executeUpdate();
			this.coxn.closeStatement(stmt);
			sql = "SELECT @@IDENTITY";
			stmt = this.coxn.prepareStatement(sql);
			rs = stmt.executeQuery();
			if (rs.next()) {
				res = rs.getInt(1);
				forum.setId(res);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			this.coxn.closeStatement(stmt);
		}
		return res;
	}
	public boolean updateForum(Forum forum) {
		boolean res = false;
		String sql = "UPDATE [forum] SET [name]=?, [descripted]=?, [topic]=? WHERE [id]=?";
		PreparedStatement stmt = null;
		try {
			stmt = this.coxn.prepareStatement(sql);
			stmt.setString(1, forum.getName());
			stmt.setString(2, forum.getDescription());
			stmt.setInt(3, forum.getTopic());
			stmt.setInt(4, forum.getId());
			stmt.executeUpdate();
			res = true;
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			this.coxn.closeStatement(stmt);
		}
		return res;
	}
}