categoryop.java

博客管理系统。安装说明： 1、在SQLSERVER中创建blog数据库并创建登陆帐号blog：blog

package huc.blog.op;

import huc.blog.bean.Blog;
import huc.blog.bean.Category;
import huc.blog.util.DateUtils;

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

public class CategoryOp extends BaseOp {

	public List getCategoryList(String userid){
		conn = db.getConnection();
		List result = new ArrayList();
		
		try {
			StringBuffer sql = new StringBuffer();
			sql.append("select * from H_CATEGORY where userid = ?");
			pst = conn.prepareStatement(sql.toString());
			pst.setString(1, userid);
			
			rs = pst.executeQuery();
			while(rs.next()){
				Category category = new Category();
				
				category.setId(rs.getString("id"));
				category.setCategoryName(rs.getString("categoryName"));
				category.setUserid(rs.getString("userid"));
				
				result.add(category);
			}
		} catch (SQLException e) {
			e.printStackTrace();
			return new ArrayList();
		}
		finally{
			close();
		}
		
		return result;
	}

	/**
	 * 添加新的类别
	 * @param category
	 * @return
	 */
	public Category add(Category category){
		conn = db.getConnection();
		try {
			StringBuffer sql = new StringBuffer();
			sql.append("insert into H_CATEGORY(");
			sql.append("userid,categoryName) ");
			sql.append(" values(?,?)");
			pst = conn.prepareStatement(sql.toString());
			pst.setString(1, category.getUserid());
			pst.setString(2, category.getCategoryName());
			
			int line = pst.executeUpdate();
			if(line == 1){
				sql.delete(0, sql.length());
				sql.append("select id from H_CATEGORY where userid=? and categoryName=?");
				pst = conn.prepareStatement(sql.toString());
				pst.setString(1, category.getUserid());
				pst.setString(2, category.getCategoryName());
				
				rs = pst.executeQuery();
				rs.next();
								
				category.setId(rs.getString("id"));
			}
			else
				category = null;
			
		} catch (SQLException e) {
			e.printStackTrace();
			return null;
		}
		finally{
			close();
		}
		return category;
	}
	
	/**
	 * 检查该类别是否已存在
	 * @param category
	 * @return
	 */
	public boolean checkCategory(Category category){
		boolean flag = false;
		conn = db.getConnection();
		try {
			StringBuffer sql = new StringBuffer();
			sql.append("select id from H_CATEGORY where userid=? and categoryName=?");
			pst = conn.prepareStatement(sql.toString());
			pst.setString(1, category.getUserid());
			pst.setString(2, category.getCategoryName());
			
			rs = pst.executeQuery();
			if(rs.next())
				flag = true;
		} catch (SQLException e) {
			e.printStackTrace();
			return flag;
		}
		finally{
			close();
		}
		
		return flag;
	}
}