jdbc进行用户信息管理

import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import java.util.Scanner;public class T_UsersTest {static Scanner s=new Scanner(System.in);static Connection conn=getConn();public static void main(String[] args) {logIn();//登录之后才具有操作权限try {conn.close();//关闭Connection} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}s.close();}/** * 获得Connection * @return */public static Connection getConn() {try {//加载驱动Class.forName("com.mysql.jdbc.Driver");//获得连接String url="jdbc:mysql://localhost:3306/java1710";String name="root";String password="0325";Connection conn=DriverManager.getConnection(url,name,password);return conn;} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}return null;}/** * 登录系统，获得对数据库的操作权限 */public static void logIn() {System.out.println("请输入用户名");String name=s.next();System.out.println("请输入password");String pw=s.next();PreparedStatement ps=null;ResultSet rs=null;try {//查询数据库中是否存在该用户String sql="SELECT * FROM T_USERS WHERE LOGINNAME=? AND USERPWD=?";ps=conn.prepareStatement(sql);ps.setString(1, name);ps.setString(2, pw); rs=ps.executeQuery();if(rs.next()) {rs.close();System.out.println("登陆成功");System.out.println("此处可以调用插入删除操作的方法");UserDao.update(1, "li", "123456", "李白");}else {System.out.println("用户名或密码错误,清重新登录");logIn();}}catch(Exception e) {e.printStackTrace();}finally {try {rs.close();} catch (SQLException e1) {// TODO Auto-generated catch blocke1.printStackTrace();}try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}/** * 方法类 * @author dingshuangen * */public static class UserDao{/** * 插入数据 */public static void insert(int userid,String loginname,String userpwd,String realname) {String sql="INSERT INTO T_USERS VALUES(?,?,?,?)";//插入sql语句PreparedStatement ps=null;try {ps=conn.prepareStatement(sql);ps.setInt(1, userid);ps.setString(2, loginname);ps.setString(3, userpwd);ps.setString(4, realname);ps.execute();}catch(Exception e) {e.printStackTrace();}finally {try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}/** * 更新用户数据 * @param userid * @param loginname * @param password * @param name */public static void update(int userid,String loginname,String password,String realname) {String sql="UPDATE T_USERS SET LOGINNAME=?,USERPWD=?,REALNAME=? WHERE USERID=?";//根据用户ID修改用户信息的sql语句PreparedStatement ps=null;try {ps=conn.prepareStatement(sql);ps.setString(1, loginname);ps.setString(2, password);ps.setString(3, realname);ps.setInt(4, userid);ps.execute();}catch(Exception e) {e.printStackTrace();}finally {try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}/** * 删除用户数据 * @param userid */public static void delete(int userid) {String sql="DELETE FROM T_USERS WHERE USERID=?";//根据用户id进行删除操作的sql语句PreparedStatement ps=null;try {ps=conn.prepareStatement(sql);ps.setInt(1, userid);ps.execute();}catch(Exception e) {e.printStackTrace();}finally {try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}}/** * 查询所有用户信息 * @return */public static List<String> select() {String sql="SELECT * FROM T_USERS";PreparedStatement ps=null;ResultSet rs=null;ArrayList<String>list=new ArrayList<String>();try {ps=conn.prepareStatement(sql);rs=ps.executeQuery();while(rs.next()) {String info="用户ID:"+rs.getInt(1)+"\t用户名:"+rs.getString(2)+"\t真实姓名:"+rs.getString(4);list.add(info);//将查询到的用户信息存储到List中}}catch(Exception e) {e.printStackTrace();}finally {try {rs.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}try {ps.close();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}}return list;}}}