datausermanager.java

一个图书管理系统

package bookManager.bo;

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

import bookManager.db.DBHelper;
import bookManager.interfaces.IUserManager;
import bookManager.vo.User;

public class DataUserManager implements IUserManager {
	Connection conn = null;

	public DataUserManager() {
		conn = DBHelper.getConnection();
		// creatUserManagerTable();
	}

	public String addUser(User user) {
		// TODO 自动生成方法存根
		String sql = "insert into USERS values(?,?)";
		try {
			PreparedStatement pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, user.getUserId());
			pstmt.setString(2, user.getUserName());
			pstmt.executeUpdate();
			return "增加用户成功！";
		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			return "失败";
		}

	}

	public String deleteUser(String userID) {
		String sql = "DELETE FROM USERS WHERE userId =?";
		PreparedStatement pstmt;
		try {
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, userID);
			int i = pstmt.executeUpdate();

			if (i > 0) {
				return "删除会员成功！！";
			} else {
				return "删除会员失败，请核对后重新输入";
			}

		} catch (SQLException e) {
			// TODO 自动生成 catch 块

			e.printStackTrace();
			return "失败";

		}

	}

	public User searchUsID(String userID) {
		User user = null;
		String sql = "select * FROM USERS WHERE  userId =?";
		PreparedStatement pstmt;
		try {
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, userID);
			ResultSet rs = pstmt.executeQuery();
			
			if (rs.next()) {
				user = new User();
				user.setUserId(rs.getString(1));
				user.setUserName(rs.getString(2));
			}

		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}

		return user;
	}

	public User searchUsName(String userName) {
		User user = null;

		String sql = "select * FROM USERS  WHERE  userName =?";
		PreparedStatement pstmt = null;
		try {
			pstmt = conn.prepareStatement(sql);
			pstmt.setString(1, userName);
			ResultSet rs = pstmt.executeQuery();
			if (rs.next()) {
				user = new User();
				user.setUserId(rs.getString(1));
				user.setUserName(rs.getString(2));
			}

		} catch (SQLException e) {
			// TODO 自动生成 catch 块
			e.printStackTrace();
		}

		return user;
	}

	public int size() {
		int count = 0;
		String sql = "SELECT COUNT(*) FROM USERS";
		PreparedStatement pstmt;
		try {
			pstmt = conn.prepareStatement(sql);
			ResultSet resultSet = pstmt.executeQuery();
			resultSet.next();
			count = resultSet.getInt(1);
		} catch (Exception e) {
			// TODO: handle exception
		}
		return count;
	}

	public List getAll() {
		
		String sql = "SELECT * FROM USERS";
		PreparedStatement pstmt = null;
		ResultSet rs = null;
		List list = new ArrayList();
		try {
			pstmt = conn.prepareStatement(sql);
			rs = pstmt.executeQuery();
			while (rs.next()) {
				User user = new User();

				user.setUserId(rs.getString(1));
				user.setUserName(rs.getString(2));

				list.add(user);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return list;
	}

	public void creatUserManagerTable() {
		try {
			conn.createStatement().execute(
					"create table users (userId varchar2(10) primary key,"
							+ "userName varchar2(20) not null)");

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}