AJAX+JAVA ユーザーのログイン登録検証を実装するコード

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>      
   请输入用户名： 
  

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; } }

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(); } } }

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; }

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); } }