users.java

新闻发布系统

package com.mynews;

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

public class users {
	private int id;
	private String name;
	private String password;
	private String grant;
	private String email;
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public String getGrant() {
		return grant;
	}
	public void setGrant(String grant) {
		this.grant = grant;
	}
	public int getId() {
		return id;
	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	
	public boolean addUser(){   //注册一个新用户
		String sql = "insert into Users values (?,?,?,?)";
		DBConnection db = new DBConnection();
		db.getConnection();
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setString(1, this.getName());
			db.prs.setString(2, this.getPassword());
			db.prs.setString(3, this.getGrant());
			db.prs.setString(4, this.getEmail());
			db.prs.executeUpdate();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
		}
		return true;
	}
	
	public users isExists(){   //判断登录用户是否存在
		String grant = "";
		String sql = "select * from Users where Name=? and Password=?";
		DBConnection db = new DBConnection();
		db.getConnection();
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setString(1, this.getName());
			db.prs.setString(2, this.getPassword());
			db.rs = db.prs.executeQuery();
			while(db.rs.next()){
				this.setId(db.rs.getInt("id"));
				this.setName(db.rs.getString("name"));
				this.setEmail(db.rs.getString("email"));
				this.setPassword(db.rs.getString("password"));
				this.setGrant(db.rs.getString("Grants"));
				return this;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
		return null;
	}
	
	public String findPassword(){   //找加密码
		String sql = "select password from Users where Name=? and Email= ?";
		DBConnection db = new DBConnection();
		db.getConnection();
		String password = "";
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setString(1, this.getName());
			db.prs.setString(2, this.getEmail());
			db.rs =  db.prs.executeQuery();
			while(db.rs.next()){
				password = db.rs.getString("Password");
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return "";
		}
		return password;
	}
	
	public boolean updateUser(){  //修改一个用户
		String sql = "update Users set Name=?,Password=?,Grants=?,Email=? where Id=?";
		DBConnection db = new DBConnection();
		db.getConnection();
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setString(1, this.getName());
			db.prs.setString(2, this.getPassword());
			db.prs.setString(3, this.getGrant());
			db.prs.setString(4, this.getEmail());
			db.prs.setInt(5, this.getId());
			db.prs.executeUpdate();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
		}
		return true;
	}
	
	public int selectId(){  //根据用户名找回用户ID
		String sql = "select Id from Users where Name=? ";
		DBConnection db = new DBConnection();
		db.getConnection();
		int id = -1;
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setString(1, this.getName());
			db.rs =  db.prs.executeQuery();
			while(db.rs.next()){
				id = db.rs.getInt("Id");
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return -1;
		}
		return id;
	}
	
	public boolean deleteUser(){   //删除一个用户
		String sql = "delete Users where Id=?";
		DBConnection db = new DBConnection();
		db.getConnection();
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setInt(1, this.getId());
			db.prs.executeUpdate();
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return false;
		}
		return true;
	}
	
	public ArrayList selectAllUsers(){//查询所有的用户信息
		String sql = "select * from Users";
		ArrayList list = new ArrayList();
		DBConnection db = new DBConnection();
		db.getConnection();
		try {
//			为了得到一个可以上下移动的结果集，须重新设置语句集为一个
			//可以滚动，可以更新的游标结果
			db.sta = db.con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
			db.rs = db.sta.executeQuery(sql);
			users  user = null; 
			while(db.rs.next()){
				user = new users();
				user.setId(db.rs.getInt(1));
				user.setName(db.rs.getString(2));
				user.setPassword(db.rs.getString(3));
				user.setGrant(db.rs.getString(4));
				user.setEmail(db.rs.getString(5));
				list.add(user);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
		return list;
	}
	
	public ResultSet selectAll(){  //查询所有记录，并返回一个结果集
		String sql = "select * from Users";
		DBConnection db = new DBConnection();
		db.getConnection();
		//为了得到一个可以上下移动的结果集，须重新设置语句集为一个
		//可以滚动，可以更新的游标结果
		try {
			db.sta = db.con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE);
			db.rs = db.sta.executeQuery(sql);
			db.rs.last();  //将指针移动到记录的最后一行
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return db.rs;
	}
	
	public String  selectName(int id){  //根据用户ID找回用户名
		String sql = "select Name from Users where Id=? ";
		DBConnection db = new DBConnection();
		db.getConnection();
		String names = "";
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setInt(1, id);
			db.rs =  db.prs.executeQuery();
			while(db.rs.next()){
				names = db.rs.getString("Name");
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return "";
		}
		return names;
	}
	
	public ArrayList selectAllNames(int id){//查询所有的用户的名字除该ID
		String sql = "select * from Users where id <> ? ";
		ArrayList list = new ArrayList();
		DBConnection db = new DBConnection();
		db.getConnection();
		try {
			db.prs = db.con.prepareStatement(sql);
			db.prs.setInt(1, id);
			db.rs = db.prs.executeQuery();
			users user = null;
			while(db.rs.next()){
				user = new users();
				user.setId(db.rs.getInt(1));
				user.setName(db.rs.getString(2));
				user.setPassword(db.rs.getString(3));
				user.setGrant(db.rs.getString(4));
				user.setEmail(db.rs.getString(5));
				list.add(user);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
		return list;
	}
	
	public Vector selectGrant(String grant){//查询所有的权限
		String sql = "select distinct Grants from users where Grants <> '"+grant+"'";
		DBConnection db = new DBConnection();
		db.getConnection();
		Vector grants = new Vector();
		try {
			db.sta = db.con.createStatement();
			db.rs = db.sta.executeQuery(sql);
			while(db.rs.next()){
				grants.add(db.rs.getString("Grants"));
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
			return null;
		}
		return grants;
	}
}