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JAVA WEB数据库操作封装 – 9.22

呐,折腾了一会儿,玩了下封装,精简了下代码,只能说一定程度上解决了代码的冗余,开发经验问题,我肯定没老手做得完美,但是我还是尽力的去解决了。代码结构如下,新建一个公共类用于封装代码

接下来是3个java类的详细代码

第一个DeleteSQL.java(类的继承)

package com.lckiss.action;

import java.io.PrintWriter;
import java.util.List;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;

public class DeletSQL extends HttpServlet {

    private static final long serialVersionUID = 1L;

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

        try {
            // 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 必须在流前定义
            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 = UserDelete(empno);
            // 打印删除结果
            System.out.println(rs);
            if (rs) {
                out.println("

" + empno + " 已删除成功

"); out.println("

编号 , 姓名 , 工作 , HIREDATA , SAL , COMM , DEPTNO.

"); List list = OracleComm.QueryALL(); for (Object c : list) { String l = (String) c; String no = l.split(",")[0]; // 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 + ""; out.println("

" + l + "-" + "删除

"); } } else { out.println("失败"); } out.flush(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public boolean UserDelete(String empno) throws Exception { String sql = "delete from emp where EMPNO=" + empno + ""; System.out.println(sql); int rs = OracleComm.ExecuteUpdate(sql); while (rs > 0) { return true; } return false; } }

第二个:OracleComm.java

package com.lckiss.action;

import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

public class OracleComm {

    public static Connection LinkSQL() throws Exception {
        String url = "jdbc:oracle:thin:@10.1.5.5:1521:orcl";
        String user = "user ";
        String password = "password ";
        new oracle.jdbc.driver.OracleDriver();
        Connection conn = DriverManager.getConnection(url, user, password);
        return conn;
    }

    public static List QueryALL() throws Exception {

        List list = new ArrayList();
        Connection conn = LinkSQL();
        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
            list.add(no + "," + ename + "," + job + "," + mgr + "," + hiredata + "," + sal + "," + comm + "," + deptno);
        }
        return list;
    }

    // 通用接口:验证是否连接成功
    public static boolean CheckUsers(String name, String pwd) throws Exception {

        String sql = "select * from emp where ENAME='" + name + "' and JOB ='" + pwd + "'";
        ResultSet rs = OracleComm.ExecuteQuerry(sql);
        while (rs.next()) {
            return true;
        }
        return false;
    }

    // 通用接口:用于执行查询语句并返回数据
    public static ResultSet ExecuteQuerry(String sql) throws Exception {
        Connection conn = LinkSQL();
        ResultSet rs = conn.createStatement().executeQuery(sql);

        return rs;
    }

    // 通用接口:用于执行更新语句并返回数据
    public static int ExecuteUpdate(String sql) throws Exception {

        Connection conn = LinkSQL();
        int rs = conn.createStatement().executeUpdate(sql);

        return rs;
    }
}

第三个:UserLogin.java (类的实现)

package com.lckiss.action;

import java.io.PrintWriter;
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 service(ServletRequest req, ServletResponse res) {
        
        String name = req.getParameter("name");
        String pwd = req.getParameter("pwd");
        // 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);
        try {
            // 设置流格式
            res.setContentType("text/html;charset=GBK");
            PrintWriter out = res.getWriter();
            // 检查数据库登录是否成功
            boolean check = OracleComm.CheckUsers(name, pwd);
            // 成功为true,反之失败
            System.out.println(check);
            if (check) {
                // 表格样式,这里由于精力问题,不考虑div包裹
                out.println("

编号 , 姓名 , 工作 , HIREDATA , SAL , COMM , DEPTNO.

"); List list = OracleComm.QueryALL(); for (Object c : list) { String l = (String) c; String no = l.split(",")[0]; // 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 + ""; out.println("

" + l + "-" + "删除

"); } } else { out.println("失败"); } out.flush(); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } @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"); } }

其他未改变,详情参照上一篇文章点我

最后上一个结果图,基本被我删得差不多了,如果你有更好的优化方案,欢迎与我探讨

本文用于博主记载自己的学习脚印,转载请注明出处。


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