userservice.java

this is very useful book for the learn of java programing.

package edu.buptsse.sxjd.service;

import java.sql.Connection;
import java.util.Hashtable;
import java.util.Vector;

import org.apache.commons.beanutils.BeanUtils;
import edu.buptsse.sxjd.dao.DAO;
import edu.buptsse.sxjd.dao.DBManager;
import edu.buptsse.sxjd.model.User;

public class UserService {

	/**
	 * 取得User表中所有用户
	 * @return
	 * @throws BusinessException
	 */
	public Vector getAllUsers() throws BusinessException{
		Connection conn = DBManager.GetConnection();
		try {
			Vector result = (Vector) DAO.executeQuery("SELECT * FROM [USER]", conn);
			return result;
		} catch (Exception e) {
			e.printStackTrace();
			BusinessException be = new BusinessException();
			be.setMessageKey("errors.Query");
			be.setMessageArgs(new String[] { e.getMessage() });
			throw be;
		}
		
	}
	

	/**
	 * 根据userid取得一个用户的信息
	 * @param id
	 * @return
	 * @throws BusinessException
	 */
	public User getUserByID(Integer id) throws BusinessException {
		String sql = "SELECT * FROM [USER] WHERE ID=?";
		// 取得connection
		Connection conn = DBManager.GetConnection();
		User user = new User();
		try {
			Vector v = (Vector) DAO.executeQuery(sql, new String[] { id
					.toString() }, conn);
			if (v.size() > 0) {
				Hashtable ht = (Hashtable) v.get(0);
				BeanUtils.copyProperties(user, ht);
			}
			return user;
		} catch (Exception e) {
			BusinessException be = new BusinessException();
			be.setMessageKey("errors.Query");
			be.setMessageArgs(new String[] { e.getMessage() });
			throw be;
		}
	}
	
	/**
	 * 新增一个用户
	 * @param user
	 * @throws BusinessException
	 */
	public void addUser(User user) throws BusinessException{
		//取得connection
		//……你的代码……
		try {
			//判断数据库里面有没有重名的记录，如果有重名的用户那么生成一个BusinessException抛出
			//……你的代码……
			//如果没有重名用户那么插入user到数据库表中
			//……你的代码……
			//更新count表中的total字段的值+1
			//……你的代码……
			//提交事务
			//……你的代码……
		} catch (Exception e) {
			//如果发生异常回滚事务，取消任何对数据库内容的更改
			//……你的代码……
			if (e instanceof BusinessException) {
				throw (BusinessException)e;
			} else {
				BusinessException be = new BusinessException();
				be.setMessageKey("errors.AddUser");
				be.setMessageArgs(new String[] { e.getMessage() });
				throw be;
			}
		}
	}
	
	/**
	 * 修改用户密码
	 * @param user
	 * @throws BusinessException
	 */
	public void modifyPWD(User user) throws BusinessException{
		//取得connection
		//……你的代码……
		try {
			//执行update使用DAO.executeUpdate(sql, values, conn)
			//……你的代码……
			//提交事务
			//……你的代码……
		} catch (Exception e) {
			//如果发生异常回滚事务，取消任何对数据库内容的更改
			//……你的代码……
			if (e instanceof BusinessException) {
				throw (BusinessException)e;
			} else {
				BusinessException be = new BusinessException();
				be.setMessageKey("errors.ModifyUser");
				be.setMessageArgs(new String[] { e.getMessage() });
				throw be;
			}
		}
	}
	
	/**
	 * 删除一个用户
	 * @param userid
	 * @throws BusinessException
	 */
	public void removeUser(String userid) throws BusinessException{
		//取得connection
		//……你的代码……
		try {
			//执行update使用DAO.executeUpdate(sql, values, conn)
			//……你的代码……
			//更新count表中的total字段的值-1
			//……你的代码……
			//提交事务
			//……你的代码……
		} catch (Exception e) {
			//如果发生异常回滚事务，取消任何对数据库内容的更改
			//……你的代码……
			if (e instanceof BusinessException) {
				throw (BusinessException)e;
			} else {
				BusinessException be = new BusinessException();
				be.setMessageKey("errors.DelUser");
				be.setMessageArgs(new String[] { e.getMessage() });
				throw be;
			}
		}
	}
}