博客应用系统开发，与mysql的链接

package org.zjy.dao; import java.sql.ResultSet; import java.util.ArrayList; import org.zjy.db.DBUtil; import org.zjy.vo.Article; public class ArticleDao { public int update(Article article){ StringBuffer sql=new StringBuffer(); int i=0; try{ sql.append("update article set title='"+article.getTitle()+"',"); sql.append("content='"+article.getContent()+"',"); sql.append("pubtime='"+article.getPubtime()+"',"); sql.append("blogid="+article.getBlogid()+","); sql.append("sortid="+article.getSortid()+" "); sql.append("where id="+article.getId()+";"); i=DBUtil.executeUpdateInsertDelete(sql.toString()); }catch(Exception ex){ ex.printStackTrace(); } return i; } public int delete(Article article){ StringBuffer sql=new StringBuffer(); sql.append("delete from article where id="+article.getId()+";"); return DBUtil.executeUpdateInsertDelete(sql.toString()); } public int save(Article article){ StringBuffer sql=new StringBuffer(); sql.append("insert into article(id,title,content,pubtime,blogid,sortid)"); int number=DBUtil.getMaxId("article")+1; sql.append("values("+number); sql.append(",'"+article.getTitle()+"',"); sql.append("'"+article.getContent()+"',"); sql.append("'"+article.getPubtime()+"',"); sql.append(article.getBlogid()+","+article.getSortid()+");"); return DBUtil.executeUpdateInsertDelete(sql.toString()); } public Article findById(int id){ Article article=null; StringBuffer sql=new StringBuffer(); sql.append("select * from article where id="+id+";"); try{ ResultSet set=DBUtil.executeQuery(sql.toString()); while(set.next()){ article=new Article(); article.setId(set.getInt("id")); article.setTitle(set.getString("title")); article.setContent(set.getString("content")); article.setPubtime(set.getString("pubtime")); article.setBlogid(set.getInt("blogid")); article.setSortid(set.getInt("sortid")); break; } }catch(Exception ex){ ex.printStackTrace(); } return article; } public ArrayList<Article> getAllArticle(){ ArrayList<Article> list=new ArrayList<Article>(); StringBuffer sql=new StringBuffer(); sql.append("select * from article order by pubtime desc"); try{ ResultSet set=DBUtil.executeQuery(sql.toString()); while(set.next()){ Article article=new Article(); article.setId(set.getInt("id")); article.setTitle(set.getString("title")); article.setContent(set.getString("content")); article.setPubtime(set.getString("pubtime")); article.setBlogid(set.getInt("blogid")); article.setSortid(set.getInt("sortid")); list.add(article); } }catch(Exception ex){ ex.printStackTrace(); } return list; } public ArrayList<Article> findByBlogIdSortId(int blogid,int sortid){ ArrayList<Article> list=new ArrayList<Article>(); StringBuffer sql=new StringBuffer(); sql.append("select * from article "); sql.append(" where blogid="+blogid); if(sortid==0){ sql.append(" order by pubtime desc;"); }else{ sql.append(" and sortid="+sortid+" order by pubtime desc;"); } try{ ResultSet set=DBUtil.executeQuery(sql.toString()); while(set.next()){ Article article=new Article(); article.setId(set.getInt("id")); article.setTitle(set.getString("title")); article.setContent(set.getString("content")); article.setPubtime(set.getString("pubtime")); article.setBlogid(set.getInt("blogid")); article.setSortid(set.getInt("sortid")); list.add(article); } }catch(Exception ex){ ex.printStackTrace(); } return list; } public ArrayList<Article> findMatchArticle(String key){ ArrayList<Article> list=new ArrayList<Article>(); StringBuffer sql=new StringBuffer(); sql.append("select * from article where title like '%"+key+"%';"); try{ ResultSet set=DBUtil.executeQuery(sql.toString()); while(set.next()){ Article article=new Article(); article.setId(set.getInt("id")); article.setTitle(set.getString("title")); article.setContent(set.getString("content")); article.setPubtime(set.getString("pubtime")); article.setBlogid(set.getInt("blogid")); article.setSortid(set.getInt("sortid")); list.add(article); } }catch(Exception ex){ ex.printStackTrace(); } return list; } public int getFeedBackTotal(int articleId){ int i=0; FeedBackDao feedBackDao=new FeedBackDao(); return i; } }