JAVA WEB数据库输出，删除-9.18

哦，一不小心现在6点了吃个饭啥的就赶紧回实验室搞定培哥的这些有趣的问题，

前面的输出信息就没什么好提的了，老师说过一次了，主要说说后面的删除表。借鉴牟球的思路，主要是出于直接用QurrayALL无法依次的到EMPNO 所以将代码整合到了service服务中。上目录结构

删除需要新建一个servlet并实现sql删除语句以下为新建的servlet内容名字为DeletSQL.java

package com.lckiss.action;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
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 DeletSQL implements Servlet {
    @Override
    public void init(ServletConfig config) throws ServletException {
    }

    @Override
    public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {
        // 从传输过来的链接中获取empno值
        String empno = req.getParameter("empno");
        // 设置格式，防止乱码
        res.setContentType("text/html;charset=GBK");
        PrintWriter out = res.getWriter();
        // 内部打印，方便检测是否出错
        System.out.println(empno);
        // 传入empno主键，删除其附属值
        boolean rs = getConnection(empno);
        // 打印删除结果
        System.out.println(rs);
        if (rs) {
            out.println("<p>" + empno + " 已删除成功</p>");
        } else {
            out.println("失败");
        }
        out.flush();
    }

    public boolean getConnection(String empno) {
        String url = "jdbc:oracle:thin:@10.1.5.5:1521:orcl";
        String user = "你的帐号";
        String password = "你的密码";
        new oracle.jdbc.driver.OracleDriver();
        try {
            Connection conn = DriverManager.getConnection(url, user, password);
            String sql = "delete from emp where EMPNO=" + empno + "";
            ResultSet rs = conn.createStatement().executeQuery(sql);
            while (rs.next()) {
                System.out.println(sql);
                return true;
            }
            conn.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return false;
    }

    @Override
    public void destroy() {
    }

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

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

——这是以前的登录类Login

package com.lckiss.action;

import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

public class UserLogin implements Servlet {
    @Override
    public void destroy() {

    }

    @Override
    public ServletConfig getServletConfig() {

        return null;
    }

    @Override
    public String getServletInfo() {

        return null;
    }

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

        System.out.println("已初始化");
    }

    @Override
    public void service(ServletRequest req, ServletResponse res) throws ServletException, IOException {

        String name = req.getParameter("name");
        String pwd = req.getParameter("pwd");
        res.setContentType("text/html;charset=GBK");
        PrintWriter out = res.getWriter();
        // 内部输出一次看从网页获取的数据是否错误
        System.out.println(name);
        System.out.println(pwd);
        // 检查数据库登录是否成功
        boolean check = getConnection(name, pwd);
        // 成功为true，反之失败
        System.out.println(check);
        if (check) {
            // true则执行，否则输出失败
            // 表格样式，这里由于经历问题，不考虑div包裹
            out.println("<p>编号 , 姓名 , 工作 , HIREDATA , SAL , COMM , DEPTNO.</p>");
            // 数据库相关信息
            String url = "jdbc:oracle:thin:@10.1.5.5:1521:orcl";
            String user = "你的帐号";
            String password = "你的密码";
            new oracle.jdbc.driver.OracleDriver();
            // 新建一个list集合对象
            List list = new ArrayList();
            try {
                // 分别为连接，查询语句，以及返回的结果集
                Connection conn = DriverManager.getConnection(url, user, password);
                String sql = "select * from emp";
                ResultSet rs = conn.createStatement().executeQuery(sql);
                // 按行循环，读完转到下一行
                while (rs.next()) {
                    int no = rs.getInt("EMPNO");
                    String ename = rs.getString("ENAME");
                    String job = rs.getString("JOB");
                    Date hiredata = rs.getDate("HIREDATE");
                    int mgr = rs.getInt("MGR");
                    int comm = rs.getInt("COMM");
                    int sal = rs.getInt("SAL");
                    int deptno = rs.getInt("DEPTNO");
                    // 以上为所以列名
                    // 因为list.add中插入这段字符串容易出错，所以单独新建一个字符串
                    String del = "http://localhost/day_1/del?empno=" + no + "";
                    list.add(no + " ," + ename + " ," + job + " ," + mgr + " ," + hiredata + " ," + sal + " ," + comm
                            + " ," + deptno + " ," + "<a href="" + del + ""> 删除</a>");
                    // 内部输出检查传递的servlet地址是否出错
                    System.out.println(del);
                }
                // 循环list集合，每一个字符串复制给一个object对象，并强制转String并输出到浏览器打印
                for (Object c : list) {
                    String l = (String) c;
                    out.println("<p>" + l + "</p>");
                }
                // 关闭Oracle conn数据流
                conn.close();
            } catch (SQLException e) {

                e.printStackTrace();
            }
            // out.println("成功");
        } else {
            out.println("失败");
        }
        out.flush();
    }

    // 验证是否连接成功
    public boolean getConnection(String name, String pwd) {
        String url = "jdbc:oracle:thin:@10.1.5.5:1521:orcl";
        String user = "你的帐号";
        String password = "你的密码";
        new oracle.jdbc.driver.OracleDriver();
        try {
            Connection conn = DriverManager.getConnection(url, user, password);
            String sql = "select * from emp where ENAME='" + name + "' and JOB ='" + pwd + "'";
            ResultSet rs = conn.createStatement().executeQuery(sql);
            while (rs.next()) {
                // 关闭Oracle conn数据流
                conn.close();
                return true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return false;
    }
}

最后，好像有人需要servlet的部署方式，截图吧，懒得搬代码了html和servlet