通过deptno查询Emp表中雇员信息（oracle）

本项目比较适合初学者浏览。

具体流程就是：当访问首页index.jsp时，加载框架，显示head.jsp里的内容，里面的下拉框的option值是从数据库里取出来显示的（通过List getDeptno()方法从数据库里取出deptno），当点击其中一个选项时，由jQuery传值到后台的同时页面在frame的name为main的框架里加载，在EmpListServlet获取到前台传过来的deptno的值，再通过List findByDno(int deptno)获取到Emp对象信息的list集合，最后将请求转发给listEmp.jsp显示。

1. 实体类Emp

package com.chinasofti.domain;

import java.util.Date;

public class Emp {
    private int empno;
    private String ename;
    private String job;
    private int mgr;
    private Date hireDate;
    private double sal;
    private double comm;
    private int deptno;

    public Emp() {
        super();
    }

    public Emp(int empno, String ename, String job, int mgr, Date hireDate, double sal, double comm, int deptno) {
        this.empno = empno;
        this.ename = ename;
        this.job = job;
        this.mgr = mgr;
        this.hireDate = hireDate;
        this.sal = sal;
        this.comm = comm;
        this.deptno = deptno;
    }

    public int getEmpno() {
        return empno;
    }

    public void setEmpno(int empno) {
        this.empno = empno;
    }

    public String getEname() {
        return ename;
    }

    public void setEname(String ename) {
        this.ename = ename;
    }

    public String getJob() {
        return job;
    }

    public void setJob(String job) {
        this.job = job;
    }

    public int getMgr() {
        return mgr;
    }

    public void setMgr(int mgr) {
        this.mgr = mgr;
    }

    public Date getHireDate() {
        return hireDate;
    }

    public void setHireDate(Date hireDate) {
        this.hireDate = hireDate;
    }

    public double getSal() {
        return sal;
    }

    public void setSal(double sal) {
        this.sal = sal;
    }

    public double getComm() {
        return comm;
    }

    public void setComm(double comm) {
        this.comm = comm;
    }

    public int getDeptno() {
        return deptno;
    }

    public void setDeptno(int deptno) {
        this.deptno = deptno;
    }

    @Override
    public String toString() {
        return "Emp{" +
                "empno=" + empno +
                ", ename='" + ename + '\'' +
                ", job='" + job + '\'' +
                ", mgr=" + mgr +
                ", hireDate=" + hireDate +
                ", sal=" + sal +
                ", comm=" + comm +
                ", deptno=" + deptno +
                '}';
    }
}

2. EmpDao和EmpDaoImpl

package com.chinasofti.dao;

import com.chinasofti.domain.Emp;

import java.util.List;

public interface EmpDao {
    //部门编号遍历
    List getDeptno();
    //根据部门编号查找雇员信息
    List findByDno(int deptno);
}

package com.chinasofti.dao.impl;

import com.chinasofti.dao.EmpDao;
import com.chinasofti.domain.Emp;
import com.chinasofti.utils.JdbcUtilsSingle;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class EmpDaoImpl implements EmpDao {

    @Override
    public List findByDno(int deptno) {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;

        List list = new ArrayList();

        try {
            conn = JdbcUtilsSingle.getInstance().getConnection();
            String sql = "select empno,ename,job,mgr,hiredate,sal,comm,deptno from emp where deptno=?";
            ps = conn.prepareStatement(sql);
            ps.setInt(1, deptno);
            rs = ps.executeQuery();
            while (rs.next()) {
                Emp e = mappingEmp(rs);
                list.add(e);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtilsSingle.getInstance().release(rs, ps, conn);
        }
        return list;
    }

    private Emp mappingEmp(ResultSet rs) throws SQLException {
        Emp e = new Emp();
        e.setEmpno(rs.getInt("empno"));
        e.setEname(rs.getString("ename"));
        e.setJob(rs.getString("job"));
        e.setMgr(rs.getInt("mgr"));
        e.setHireDate(rs.getDate("hiredate"));
        e.setSal(rs.getDouble("sal"));
        e.setComm(rs.getDouble("comm"));
        e.setDeptno(rs.getInt("deptno"));
        return e;
    }

    @Override
    public List getDeptno() {
        Connection conn = null;
        PreparedStatement ps = null;
        ResultSet rs = null;

        List list = new ArrayList();

        try {
            conn = JdbcUtilsSingle.getInstance().getConnection();
            String sql = "select distinct deptno from emp";
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            while (rs.next()) {
                list.add(rs.getInt("deptno"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JdbcUtilsSingle.getInstance().release(rs, ps, conn);
        }
        return list;
    }
}

3. service层EmpService和EmpServiceImpl

package com.chinasofti.service;

import com.chinasofti.domain.Emp;

import java.util.List;

public interface EmpService {
    List getDeptno();
    List findByDno(int deptno);
}

package com.chinasofti.service.impl;

import com.chinasofti.dao.EmpDao;
import com.chinasofti.dao.impl.EmpDaoImpl;
import com.chinasofti.domain.Emp;
import com.chinasofti.service.EmpService;

import java.util.List;

public class EmpServiceImpl implements EmpService {
    private EmpDao empDao = new EmpDaoImpl();

    @Override
    public List getDeptno() {
        return empDao.getDeptno();
    }

    @Override
    public List findByDno(int deptno) {
        return empDao.findByDno(deptno);
    }
}

4. 显示层index.jsp,head.jsp,listEmp.jsp

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>


    


    
    

head.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


    
    
    


雇员列表


部门编号：
    请选择：
    
        ${dno}
    

listEmp.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


    



        

    

        
雇员编号
        
雇员姓名
        
雇员工作
        
上级编号
        
雇用日期
        
雇员工资
        
雇员奖金
        
部门编号
    
    

            
${c.empno}
            
${c.ename}
            
${c.job}
            
${c.mgr}
            
${c.hireDate}
            
${c.sal}
            
${c.comm}
            
${c.deptno}
        
    

5. 控制层DeptnoServlet和EmpListServlet

DeptnoServlet

package com.chinasofti.web;

import com.chinasofti.service.EmpService;
import com.chinasofti.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "DeptnoServlet", urlPatterns = "/DeptnoServlet")
public class DeptnoServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        EmpService empService = new EmpServiceImpl();
        List list = empService.getDeptno();
        request.setAttribute("list", list);
        request.getRequestDispatcher("/head.jsp").forward(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }
}

EmpListServlet

package com.chinasofti.web;

import com.chinasofti.domain.Emp;
import com.chinasofti.service.EmpService;
import com.chinasofti.service.impl.EmpServiceImpl;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@WebServlet(name = "EmpListServlet", urlPatterns = "/EmpListServlet")
public class EmpListServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        int deptno = Integer.parseInt(request.getParameter("deptno"));
        System.out.println(deptno);
        EmpService empService = new EmpServiceImpl();
        List list = empService.findByDno(deptno);
        request.setAttribute("list",list);
        request.getRequestDispatcher("/listEmp.jsp").forward(request,response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);
    }
}

源代码：https://github.com/yvettee36/JdbcEmp