通用数据库操作类及员工信息查询实例

江山如画 • 2019年11月27日上午8:01 • 编程开发 • 阅读 20241

package com.common;
import java.sql.*;
public class DataBaseConn {
public  Connection conn = null;
public void createConn(){
  String url = "jdbc:mysql://localhost:3306/employeeDb"; 
  String username = "root";// 数据库用户名
String password = "root";// 数据库密码
  if(conn == null){
   try{ Class.forName("com.mysql.jdbc.Driver");
     conn = DriverManager.getConnection(url,username,password);
    }catch(Exception e){e.toString();}
  }
} 
public  Connection getConn(){
  	if(conn == null){  createConn();}
  	return conn;
 } 

 public  void closeConn(){
     if(conn != null){
   	try {
    		conn.close();
   	 	conn = null;
   	} catch (Exception e) {   	 e.printStackTrace();   }
     }
 }
 public ResultSet executeQuery(String sql) {
  	ResultSet rs = null;
 	 if (conn == null) {createConn();}
  	try {
 		 Statement stmt = conn.createStatement();
  		 rs = stmt.executeQuery(sql);
  	} catch (Exception e) {   e.printStackTrace();  }
   return rs;
 } 
public void executeUpdate(String sql) {
  if (conn == null) {createConn(); }
       try {  Statement stmt =    conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_READ_ONLY);
      stmt.executeUpdate(sql);
     } catch (Exception e) {   e.printStackTrace();  }
 }
}

<jsp:useBean id="con" class="com.common.DataBaseConn" scope="page"/>
<%    con.getConn();
     String  sql="select * from  employee_info";
     ResultSet rs= con.executeQuery(sql); 
 %>
<table border='1' width='100%'>
 <tr> <th>雇员号</th> <th>姓名</th> <th>出生日期</th><th >薪水</th></tr>
     <% 
while( rs.next() ) {  out.print("<tr>");
             out.print("<td >"+rs.getString(1)+"</td>"); 
             out.print("<td >"+rs.getString(2)+"</td>");
             out.print("<td >"+rs.getDate("birthday")+"</td>"); 
             out.print("<td >"+rs.getInt("salary")+"</td>");
              out.print("</tr>") ;   }
        out.print("</table>");
        con.closeConn();
    %>

125jz网原创文章。发布者：江山如画，转载请注明出处：http://www.125jz.com/4265.html