Servlet 5—— 在servlet中编写JDBC接口

美好的一天从搞崩eclipse开始，也许是我昨天看了追了部电视剧，向涵之真好看，程序员不配拥有爱情（我不信）。

言归正传，一个下午还是有收获的复习了JDBC，然后编写了servlet的一个重点。

 index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>index page</title>
</head>
<body>
    <a href="./system/list">显示员工信息</a>
</body>
</html>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
    <servlet>
        <servlet-name>listEmpServlet</servlet-name>
        <servlet-class>web.listEmpServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>listEmpServlet</servlet-name>
        <url-pattern>/system/list</url-pattern>
    </servlet-mapping>
</web-app>

listEmpServlet.java

package web;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class listEmpServlet implements Servlet {

    @Override
    public void destroy() {

    }

    @Override
    public ServletConfig getServletConfig() {
        return null;
    }

    @Override
    public String getServletInfo() {
        return null;
    }

    @Override
    public void init(ServletConfig arg0) throws ServletException {

    }

    @Override
    public void service(ServletRequest request, ServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        out.print("<html>");
        out.print("<head>");
        out.print("<meta charset='UTF-8'>");
        out.print("<title>员工信息</title>");
        out.print("</head>");
        out.print("<body>");
        out.print("<h3 align='center'>员工列表</h3>");
        out.print("<hr width='60%'>");
        out.print("<table border="1" align="center" width="50%">");
        out.print("<tr align="center">");
        out.print("<th>序号</th>");
        out.print("<th>员工编号</th>");
        out.print("<th>员工姓名</th>");
        out.print("<th>员工薪水</th>");
        out.print("</tr>");

        // JDBC
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/MySQL", "root", "root");
            String sql = "select empno,ename,sal from login.emp";
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            int i = 0;
            while (rs.next()) {
                String empno = rs.getString("empno");
                String ename = rs.getString("ename");
                String sal = rs.getString("sal");
                out.print("<tr align="center">");
                out.print("<th>" + ++i + "</th>");
                out.print("<th>" + empno + "</th>");
                out.print("<th>" + ename + "</th>");
                out.print("<th>" + sal + "</th>");
                out.print("</tr>");
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (ps != null) {
                try {
                    ps.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }

        out.print("</table>");
        out.print("</body>");
        out.print("</html>");
    }

}

 

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原文地址：https://www.cnblogs.com/stu-jyj3621/p/14354555.html