利用web.xml配置数据库

1.web.xml 配置
 
 
 
  dbUrl
  jdbc:mysql://localhost:8080/auth
 
 
  driverName
  com.jdbc.mysql.Driver
 
 
  userName
  root
 
 
  passWord
  123456
 
  1

 

2.初始化

	private String dbUrl;
	private String driverName;
	private String userName;
	private String passWord;
	private Connection conn=null;
	private PreparedStatement ps=null;
	private ResultSet rs=null;
	@Override
	//初始化
	public void init(ServletConfig config) throws ServletException {
		//读取配置文件里面的信息
		this.dbUrl=config.getInitParameter("dbUrl");
		this.driverName=config.getInitParameter("driverName");
		this.userName=config.getInitParameter("userName");
		this.passWord=config.getInitParameter("passWord");
	}

3.操作

3.1.查询
public String getNickName(String openid) throws SQLException{
		String nickName="";
		conn = DriverManager.getConnection(dbUrl,userName,passWord);
		String sql="select * from user where OPENID=?";
		ps = conn.prepareStatement(sql);
		ps.setString(1, openid);
		rs = ps.executeQuery();
		while(rs.next()){
			nickName=rs.getString("NICKNAME");
		}
		rs.close();
		ps.close();
		conn.close();
		return nickName;
	}
3.2 更新
public int updUser(String openid,String userName,String passWord) throws SQLException{
		String nickName="";
		conn = DriverManager.getConnection(dbUrl,userName,passWord);
		String sql="update user set OPENID=? where USERNAME=? and PASSWORD=?";
		ps = conn.prepareStatement(sql);
		ps.setString(1, openid);
		ps.setString(2, userName);
		ps.setString(3, passWord);
		int temp=ps.executeUpdate();
		rs.close();
		ps.close();
		conn.close();
		return temp;
	}