AJAX+JAVA用户登陆注册验证

摘要：需求通过异步刷新页面验证用户输入的账号密码是否在数据库中存在。下面是下查询的代码查询用户名是否存在语句连接代码关于类关于控制层获取到输入的用户名调用中的查询方法设置字符编码关闭资源

通过ajax异步刷新页面验证用户输入的账号密码是否在数据库中存在。

JSP+Servlet+Oracle

JSP部分：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>








    请输入用户名：
    

这里没有用Dao层，直接用servlet和service层进行验证。
下面是service下JDBC查询的代码：

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import com.stx.service.User;
import com.stx.service.ConnectionManager;

public class ajaxService {
    public boolean  searchUser (String uname) {
    //jdbc查询用户名是否存在
        boolean isFalse = false;
        Connection connection = null;
        Statement stmt = null;
        ResultSet rs = null;
        connection = ConnectionManager.getConnection();
        try {
            stmt = connection.createStatement();
            String sql = "select * from user_b where uname=""+uname+""";//sql语句
            rs = stmt.executeQuery(sql);
            isFalse=rs.next();

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            ConnectionManager.closeResultSet(rs);
            ConnectionManager.closeStatement(stmt);
            ConnectionManager.closeConnection(connection);
        }
        return isFalse;
    }
}

JDBC连接代码：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class ConnectionManager {
    private final static String DRIVER_CLASS = "oracle.jdbc.OracleDriver";
    private final static String URL = "jdbc:oracle:thin:@localhost:1521:orcl";
    private final static String DBNAME = "ibook";
    private final static String PASSWORD = "qwer";

    public static Connection getConnection() {
        Connection connection = null;
        try {
            Class.forName(DRIVER_CLASS);
            connection = DriverManager.getConnection(URL, DBNAME, PASSWORD);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }

    public static void closeResultSet(ResultSet rs) {
        try {
            if (rs != null)
                rs.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void closeConnection(Connection connection) {
        try {
            if (connection != null && !connection.isClosed())
                connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public static void closeStatement(Statement stmt) {
        try {
            if (stmt != null)
                stmt.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

关于user类：

 public class User {
        private String uname;
        public User() {
            super();
        }
        public User(String uname) {
            super();
            this.uname = uname;
    
        }
    
        public String getUname() {
            return uname;
        }
        public void setUname(String uname) {
            this.uname = uname;
        }

关于控制层servlet：

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.stx.service.ajaxService;

/**
 * Servlet implementation class loginServlet
 */
public class loginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private ajaxService ajaxService = new ajaxService();

    /**
     * @see HttpServlet#HttpServlet()
     */
    public loginServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        String uname = request.getParameter("uname");//获取到输入的用户名
        boolean isUname = ajaxService.searchUser(uname);//调用service中的查询方法
        response.setCharacterEncoding("UTF-8");//设置字符编码
        PrintWriter out = response.getWriter();
        out.print(isUname);
        out.flush();
        out.close();//关闭资源
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}